Apocynaceae (Dogbane Family) Teñoso, J.1 and Salvador, M.2 1 Student, 2Faculty, Dept. of Biology, College of Science, Polytechnic University of the Philippines ABSTRACT Apocynaceae (Dogbane and Milkweed Family) is a taxon under the order Gentianales. It contains 424 genera that are grouped into five subfamilies: Rauvolfioideae, Apocynoideae, Periplocoideae, Secamonoideae and Asclepiadoideae. Recently, Asclepiadaceae was recommended to be included within Apocynaceae to make the latter monophyletic, since the former is accounted to be an apomorphic derivative of Apocynaceae. Keywords: Apocynaceae, Gentianales, Asclepiadaceae, monophyletic. INTRODUCTION Taxonomy have been designed to group and classify species based either on natural or artificial system. It acts as an effective communication tool in biology. The traditional system, Linnaean system of classification, is based on reproductive features of plants. Binomial nomenclature was used as a standard for naming organisms. This helps reduce changes that may take place from time to time. Moreover, the phylogenetic system is now widely used for classification since it drastically reduces subjective changes in taxon circumscription. It shows genetic relationships and phylogeny among interrelated organisms. One of the problematic groups in plant systematics is the Apocynaceae (ca. 424 genera). It belongs to the order Gentianales and is pantropic /subtropic in distribution, with few temperate members. Well-known ornamentals belong to this family like Nerium (oleander) and Hoya (wax flower). They contain milky latex and produce various alkaloids and cardenolides. Phytoactive compounds found in this family showed great promise. Vinblastine and vincristine used for the treatment of childhood leukemia are found in Catharanthus (rose periwinkle). Here, Apocynaceae, its subfamilies and tribes, botanical description and economic uses of representative species are discussed. METHODOLOGY Botanical review by Endress (2000; 2004) and Bruyns (2000) and phylogenetic studies by Sennblad and Bremer (2002) were used as the basis for this paper. Journals and articles about Apocynaceae and Asclepiadaceae were also taken into consideration. Online floras were utilized for the morphological description of representative species. RESULTS AND DISCUSSION Robert Brown published two papers, Prodromus Flora Novae Hollandiae and On the Asclepiadeae, in 1810. In the later paper, he separated the Asclepiadaceae from Apocynaceae of Jessieu (1789). The presence of complex translators and pollinia in the former and absence in the later was the said reason. The taxonomy between the two is still a controversy whether as it should be in one family, order separate from Gentianales or a suborder within Gentianales. However, as of today, none of this has met such acceptance. And they are usually maintained as two families in Gentianales. By molecular studies, however, Brown’s delimitation does not elicit natural relationship. Infrafamilial Classification of Apocynaceae Two subfamilies in Apocynaceae are recognized: the Plumerioideae (=Ravolfioideae) and Apocynoideae. Additional subfamilies were also recognized, although ambiguous: Tabernaemontanoideae Stapf (1902), Apocynoideae sensu Woodson (1930), Cerberoideae Richon (1948) and Carissoideae Endlicher (1838). Rauvolfoideae is considered more basal and heterogeneous than Apocynoideae. The former typically have corolla lobes sinistrorsely contorted in bud, anthers mostly unspecialized and free from style head and broad array of fruit and seed types; contrariwise, the Apocynoideae have corolla lobes dextrorsey contorted in bud, anthers specialized with lignilied rails and adnate to style head, forming gynostegium and fruit almost always a dry follicle with comose seeds. Rauvolfioideae has the least specialized flowers in the family (with an exemption from Tabernaemontanaeae that has lignified guide rails on anthers). Its flower is typically small, whitish and possesses salveriform corolla tube. Anthers of this subfamily are small and ovate and not adnate to style head. Problem is prevalent in searching for stable floral characters to distinguish tribes of Rauvolfioideae with monotonously alike flowers. Placement of species in tribes of this family has been always based on fruit characteristics, but this method is overly simplistic. Recent researches proposed that fleshy, indehiscent fruit have evolved at least three tribes. Pichon (1948) by far has the most comprehensive way of grouping rauvolfioid tribes – by the inner pericarp. Carisseae, Ambelanieae and Maucobeeae have fleshy, indehiscent berry. Those with deshiscent follicles with arillate seeds are Chilocarpae and Tabaernaemontanae. Three groupings were made for those with dry inner pericarp: spiny unilocular capsule, Allamandeae; indehiscent drupe with a stony endocarp, Ravolfiae (=Alyxieae sensu Lee); and, pair of dehiscent follicles with dry pericarp and usually winged seed, Alstonieae (=Plumeria sensu Leeuwenberg). Apocynoideae are more homogenous compared to that of Rauvolfioideae. Pichon described four tribes: Parsonsieae, Nerieae, Ecdysanthereae and Ichnocarpeae; to which he based the classification on the way anthers are united with style head termed as retinacle. This part has not been used by most apocynologists since it is easily ruptured during studies. Leeuwenberg (1994) proposed that Apocynoideae are so closely interrelated and possibly impossible to group the tribes or subtribes. He reassigned Pichon’s Parsonsieae and Nerieae to Echiteae and Wrightieae, respectively, and amalgamated the Ecdysanthereae and Ichnocarpeae to Apocyneae. Now, five tribes are recognized based on retinacle morphology and preliminary DNA results: Wrightieae, Malouetieae, Apocyneae, Echiteae and Mesechiteae. Recognition of Family Periplocaceae In 1905, Schlechter separated Periplocaceae from Asclepiadaceae. The former having pollen tetrads that ere loosely deposited on scooplike translators attached to a soft, sticky, nearly amorphous viscidium while the latter having pollen gathered in pollinia and attached to a cliplike corpuscle. Periplocoideae and remainder of Asclepiadaceae are thus separated based on the presence of soft, sticky, somewhat amorphous viscidium versus presence of harder corpuscle, not by the mere presence or absence of pollinia. Periplocoideae have anthers free from stlye head, as compared to asclepiads that have fused anthers forming a gynostegium. Kunze, in 1990 and 1996, proposed for the separation of Periplocaceae as a distinct family. Differences in the bases of the stamens between Periplocaceae and Asclepiadoideae was the sought reason for the separation – the former has swollen region below filaments, termed as basal tube or corolline or receptacle; and the latter has border between a receptacular base of the stamina column and in upper part in which filaments are fused. Each stamen of the Periplocoideae have small, approximately cylindrical filament beneath the anther, located at different heights on corolla tube but always are on the apex of thickened ridge called staminal foot. Other facets for the further differentiation of Periplocoideae include corona (consists of three parts: a robust central lobule directly behind the base of the filament attached on the apex of stamina foot, and two smaller lobules lateral to the middle one) and nectaries (positioned on sides of staminal foot and/or ridges between them, usually below the filament). Although characteristics have been discussed above for the separation of Periplocoideae as a separate family, little morphological support is established. Venter and Verhoeven (1997) attempted to classify the tribes based on floral states. Tribes of the subfamily have not been discussed by Endress and Bruyns (2000) since some species of Periplocoideae that they know do not fit well in the classification. Also, conflicts have arisen with the molecular analyses of Civeyrel (1996). Recognition of the Family Secamonoideae Secamonoideae’s status by the time of Brown was still ambiguous and was grouped within Cynanchoideae (=Asclepiadoideae). This subfamily falls relatively between Periplocoideae and Asclepiadoideae. The corpuscle in some genera ascends as a single body that is U-shaped in cross section and develops vertically with secretory fields. Each anther of this subfamily grows four locules and subsequently produces four pollinia. The pollinia composed if tetrads held together by cross-wall fusion, without an outer wall enclosing the pollinium. Relationships within the Asclepiadoideae Four tribes are documented in Asclepiadoideae: Marsdenieae, Stapelieae (=Ceropegieae), Asclepiadeae and Gonolobeae. One new tribe, Fockeeae, have been separated from Marsdenieae since the former lack caudicles and floor in the lower third of the corpuscle. Also, stamens with large apical appendages were taken into consideration. However, few molecular analyses have been made regarding this new tribe. Marsdenieae is the most basal tribe of Asclepiadoideae. It lacks hyaline insertion crest on the upper or outer edge of the pollinium and somehow outer corona – features contrasted to Ceropegieae. Also, Marsdenieae have smooth and hairless sead coat, as directly opposed by Asclepiadeae. Asclepiadeae is cosmopolitan with specific concentrations in Africa and New World. They have large and conspicuously flattened pendulous pollinia. The Gonolobeae is poorly known since little evidences have been made. Woodson (1941) characterized this subfamily by the features of the pollinarium (the horizontal to rarely pendulous broad pollinia with a hyaline insertion creat and usuallu at least one partly concave face). Kunze (1995) showed that insertion crest becomes lodged in the guide rail and that growth of the pollen tube takes place through the concave face of the pollinium. Stepelieae have pollinia attached to the caudicles at their bases, anther sacs not imbedded in tissue of anther wings anther wings always below level of anther sac and style head separated from ovaries by a sharp constriction, with the gynoecium lacking of a true style. In the molecular study made by Sennblad and Bremer (1996), they reduced the Gonolobeae to be a subtribe Asclepiadeae; but only two species were sequenced. It thus lack clear morphological and phylogenetic identities. Taxonomic Treatment taken from Endress and Bruyns (2000) Apocynaceae Jussieu (1789) Woody climbers, vines, perennial herbs, trees or shrubs, more rarely annuals. Latex usually milky, sometimes clear, rarely yellow or red. Leaves simple and entire, normally petiolate, rarely sessile, usually opposite, rarely alternate or whorled; stipules absent or small and caducous, almost always with toothlike colleters in axil of leaf, sometimes on petiole, in a cluster adaxially at juncture of petiole and base of lamina or along midrib above, rarely with domatia abaxially in axils of veins. Flowers perfect, rarely functionally dioecious, actinomorphic, very rarely slightly zygomorphic, almost always 5-merous except for gynoecium of two carpels (rarely more). Calyx mostly with colleters within at base. Corolla salveriform, infundibuliform, tubular, or rotate. Petals usually contorted in bud, either dextrorse or sinistrorse, more rarely valvate. Corolline or gynostegial coronas often present. Stamens inserted on corolla tube, on staminal feet, or on staminal tube. Anthers mostly highly elaborated and with lignified guide rails and normally with apical connective appendage, mostly attached to style- head, forming gynostegium (free from style head and mostly without guide rails in Rauvolfioideae). Pollen when shed in single grains, in tetrads, in tetrads collected into weakly cohesive pollinia or tightly bound into pollinia with waxy outer covering (ectexine). Nectar secreted in altemistaminal troughs on staminal tube or staminal feet or from disclike nectary around base of ovary, more rarely from sides of ovary or absent. Ovary mostly apocarpous, superior to subinferior; placentation marginal when ovary apocarpous, parietal or axile when syncarpous, upper part of carpels fusing postgenitally to form complex style head that produces adhesive for pollen transport, with pollen-trapping basal collar and/or pollen-presenting upper crest present in many Rauvolfioideae and Apocynoideae; stigma mostly on underside of style head, often restricted to five chambers behind guide rails, but laterally uniformly receptive in some Rauvolfioideae. Adhesive a formless, sticky foam or mucilage, or as five translators with scooplike pollen receptacle and sticky base, or as five hard clips (corpus- cules), usually accompanied by five pairs of flexible arms (caudicles). Fruit mostly a pair of ventrally dehiscent follicles (often only one due to abortion) (rarely a capsule), with small seeds with a micropylar coma, rarely with a chalazal coma or ecomose (fruits in Rauvolfioideae drupes, berries, follicles, or capsules; seeds usually ecomose, naked, winged, or arillate). I. Rauvolfioideae Kostel (1834). Trees, shrubs, woody lianas or vines, rarely herbs. Latex usually milky, rarely reddish or yellowish. Leaves opposite, whorled, or alternate. Calycine colleters often lacking, when present usually in single series (but characteristically multiseriate in Tabernaemontaneae); corolla mostly salveriform, rarely with inflated throat (tubular campanulate or infundibuli- form); corolla lobes mostly not inflexed in bud (except in some Tabernaemontaneae and Alyxieae); aestivation almost always sinistrorse; corona when present almost always in the staminal sector, usually of simple lobes or pouches in petal sinuses (rarely fused into annu- lus), sometimes lower down on corolla tube above stamen; anthers included in corolla tube, usually fertile to base (fertile in upper part only and with sterile lignified basal appendages in most Tabernaemontaneae), free from style head; ovary congenitally syncarpous or apocarpous, very rarely postgenitally syncarpous; stigma restricted to the base of the style head, or entire body of style head uniformly receptive. Nectaries surrounding base of ovary, adnate to outer ovary wall or absent. Fruit dehiscent or indehiscent; pericarp fleshy or dry; endocarp sometimes lignified, forming a stone around the seed(s); seeds generally naked or winged, testa glabrous or hairy, smooth, or pitted, ridged or rugulose, without coma (except in Haplophyton), sometimes with pronounced hilar furrow; endosperm smooth, sometimes ridged or ruminate. Pollen mostly 3-4colporate, but typically porate and often with only 2 apertures in Alyxieae and a few Melodineae. Indole alkaloids often present, iridoid glycosides and carde- nolides less frequently. Tribes of Rauvolfioideae 1. Alstonieae G. Don (1838). Trees or shrubs. Latex usually milky, but often reddish or yellowish in Aspidosperma. Leaves alternate, whorled, or opposite. Calycine colleters absent; corolla salveriforrn or somewhat funnelform in Haplophyton; corolla-lobe aestivation either sinistrorse or dextrorse; corona absent; style head with or without a basal collar; ovary apocarpous or rarely 2. 3. syncarpous; disc absent, adnate, or inconspicuous. Fruit normally with dry pericarp and dehiscent, a pair of follicles or these rarely fused, but fruit fleshy in Geissospermum and Vallesia; endocarp usually not forming a stone (except in Vallesia); ovules several to numerous per carpel. Seeds various: thin and compressed with wing, or with hairs around margin, which often become longer at ends (Alstonia, Tonduzia, Laxoplumeria), or seeds not compressed and with coma at both ends (Haplophyton) or naked (Microplumeria, Vallesia). Endosperm smooth. Pollen 3colporate. Secondary chemistry indole alkaloids, x = 10, 11. Distribution: Old World and New World, tropics, subtropics. Vinceae Duby(1828). Trees or shrubs, more rarely lianas, vines, or herbs, with milky latex. Leaves whorled or opposite, rarely alternate. Calycine colleters absent; corolla salveriform; corolla-lobe aestivation usually sinistrorse (dextrorse in Kopsia, Neisosperma, and Ochrosia); corona absent; style head usually with stigmatic region beneath basal collar; disc normally present; ovary apocarpous (in some Rauvolfia spp. hemisyncarpous), often only one carpel maturing. Fruit either indehiscent, drupaceous with a fleshy pericarp and indurated endocarp forming a stone, or a pair of dehiscent follicles; seeds 1-4(-6) per carpel, rarely more, ovoid or compressed (the flat margins forming a ledge in Kopsia, Ochrosia, and Neisosperma). Endosperm usually fleshy and smooth (very thin or apparently absent in Kopsia). Pollen mostly 3-colporate. Secondary compounds indole alkaloids, x = 9, 10, 11, 23. Distribution: Old World and New World, tropics, subtropics, and temperate. Willughbeeae A. DC. (1844). Trees, shrubs, or woody lianas, the last often with grappling tendrils, with milky latex. Leaves opposite; calycine colleters present or absent; corolla salveriform; corolline corona absent; corollalobe aestivation almost always sinistrorse; apical connective appendages of anthers often scarcely developed; style head usually with stigmatic region beneath basal collar, sometimes body uniformly receptive; ovary 4. 5. congenitally syncarpous; disc mostly adnate or in- distinct from ovary. Fruit indehiscent, a berry with fleshy, nonfibrous pericarp and placentas usually pulpy in fruit; endocarp not forming a stone; seeds usually numerous, embedded in pulp, with or without longitudinal furrow; endosperm smooth or wrinkled longitudinally. Pollen (1-)3(--4)colporate. Secondary chemistry indole alkaloids, x = 11. Distribution: Old World and New World, tropics. Tabernaemontaneae G. Don. (1838). Trees or shrubs, rarely lianas, with milky latex. Leaves opposite. Calycine colleters mostly present, often multiseriate; corolla salveriform or rarely funnelform; corolla lobes often in- flexed in bud; aestivation almost always sinistrorse; corona mostly absent; anthers with ligni- fled guide rails; style head with stigmatic region beneath basal collar or flange and usually with (often 5-ribbed) upper wreath or style head subglobose and without basal collar and upper wreath and body uniformly receptive; ovary apocarpous or syncarpous; disc adnate, indistinct, or free. Fruit with fleshy pericarp, either an indehiscent berry with the seeds usually embedded in pulp or a pair of dehiscent follicles with arillate seeds; seeds often with deep hilar groove on one side and longitudinal grooves on the other or testa wrinkled or pitted; endocarp not forming a stone; endosperm ruminate. Pollen 3-5colporate. Secondary chemistry highly evolved in- dole alkaloids of the heynean type. n = 11. Distribution: Old World and New World, tropics. Melodineae G. Do. (1838). Lianas, trees, or shrubs, with milky latex. Leaves opposite or whorled. Calycine colleters usually absent; corolla salveriform; corolla-lobe aestivation sinistrorse; small corolline corona often present in petal sinuses (well developed and often annular in Melodinus); anther connective with a apical extension in Diplorhynchus and Dyera and with both apical connective extension and small sterile basal lobes in Pycnobotrya; style head mostly without basal collar or upper wreath; disc usually absent; ovary apocarpous or syncarpous, sometimes 6. 7. only at base (Diplorhynchus), more than half inferior in Dyera. Fruit mostly a pair of follicles with dry pericarp (fruit a capsule in Craspidospermum and a fleshy berry in Melodinus); endocarp not forming a stone; seeds usually numerous, smooth, fiat, and winged, often peltately attached with long funicle (somewhat verrucose, only slightly compressed, and embedded in pulpy placenta in Melodinus). Endosperm mostly smooth. Pollen usually 3-colporate (in tetrads in some Melodinus species and porate tetrads in Craspidospermum). Secondary compounds indole alkaloids, x = 10, 11. Distribution: Old World, tropics, rarely subtropics. Hunterieae Miers (1878). Trees or shrubs, with milky latex. Leaves opposite. Calycine colleters mostly present, often multiseriate, rarely absent; corolla salveriform; corolla-lobe aestivation sinistrorse; corona absent; style head uniformly receptive, ovoid to narrowly clavate, with neither basal collar nor upper wreath but often with slender, elongate nonreceptive apices; ovary apocarpous, 2-5carpellate; disc adnate or indistinct. Fruit a composite berry of 2-5 distinct mericarps with fleshy, fibrous pericarp; endocarp not forming a stone; seeds ovoid, embedded in pulp; endosperm smooth. Pollen 3-colporate. Secondary chemistry indole alkaloids, n = 11. Distribution: Old World, tropics. Plumerieae E. May. (1838). Trees or shrubs, the latter sometimes scrambling, with milky latex; leaves usually alternate, sometimes opposite (whorled in Allamanda). Calycine colleters absent or present; corolla salveriform or funnelform; corolla-lobe aestivation sinistrorse; corolline corona often present below the petal sinuses behind stamen (usually much dissected in Allamanda) and infrastaminal appendages generally present; anther connective often broadened and with elon- gate apical extension; style head mostly with basal collar or lobes (no distinct basal collar in Plumeria, Himatanthus, or Mortoniella), mostly without upper wreath (well-developed upper wreath present in Allamanda) but often with free apices conspicuously enlarged; ovary apocarpous or 8. 9. syncarpous at the very base (postgenitally syncarpous in Allamanda), hemi-inferior in Plumeria, Himatanthus, and Mortoniella; disc absent or present. Fruit mostly a dehiscent pair of follicles (a capsule in Allamanda) or indehiscent and drupaceous (samaroid in Cerberiopsis) with fleshy or dry pericarp; plancentas often lignified in fruit; endocarp sometimes forming a stone; seeds 1-4(-many) per carpel, usually with compressed, winglike margin or distinct papery wing. Endosperm smooth, mostly thin. Pollen 3-colporate. Secondary compounds cardenolides or iridoid glycosides (in Skytanthus, Skytanthus alkaloids), x = 9, 10. Distribution: Old World and New World, tropics and subtropics. Carisseae Dumort (1829). Shrubs with (often branched) spines in leaf axils, with milky latex. Leaves opposite; calycine colleters present or absent; corolla salveriform; corona absent; corolla-lobe aestivation sinistrorse or dextrorse; style head scarcely differentiated, without basal collar, body uniformly receptive; ovary congenitally syncarpous; disc mostly absent or adnate to ovary. Fruit indehiscent, a berry with fleshy, nonfibrous pericarp; endocarp not forming a stone, but placentas becoming lignified in fruit forming woody partition; seeds 2-6(-12), rarely more, compressed; endosperm smooth. Pollen 3colporate. Secondary chemistry cardenolides, x = 11. Distribution: Old World, tropics and subtropics. Alyxieae G. Don. (1838). Trees, shrubs, or vines, with milky latex. Leaves alternate, opposite, or whorled. Calycine colleters absent; corolla salveriform (sometimes throat somewhat expanded in Condylocarpon); corolla lobes often deeply inflexed in bud; aestivation sinistrorse; corona absent; style head with neither basal collar nor upper wreath, body uniformly receptive; ovary apocarpous or syncarpous (Lepiniopsis and Chilocarpus); in Plectaneia carpels free except for narrow, congenitally fused region in the center of their ventral flanks) and up to 5carpellate in Lepinia and Lepiniopsis often stipitate; disc absent, indistinct, or adnate. Fruit mostly indehiscent, with fleshy pericarp and endocarp usually forming a stone (pericarp dry in Condylocarpon and Chilocarpus dehiscent; fruit capsular, dry, and dehiscent in Plectaneia); seeds normally not compressed, usually elongate, globular, or ovoid, longitudinally rolled with deep hilar furrow and ruminate endosperm (compressed and with wing in Plectaneia, arillate in Chilocarpus). Pollen 2-3-porate, typically barrel shaped (in tetrads and inaperturate in Condylocarpon). Neither alkaloids nor cardenolides are known to occur in the tribe, x = 9 (known only for Alyxia). Distribution: Pacific Basin and Asia; Condylocarpon in the New World, tropics. II. Apocynoideae Burnett (1835). Woody lianas, vines, less frequently trees or shrubs, rarely perennial herbs. Latex usually milky (often clear in Echiteae and some Wrightieae). Leaves almost always opposite, sometimes with adaxial cluster of colleters at juncture of petiole apex and blade base (some Mesechiteae and Apocyneae) or domatia abaxially in axils of secondary veins with midvein (some Malouetieae, Mesechiteae, and Apocyneae). Calycine colleters normally present; co- rolla infundibuliform, tubular eampanulate, salveriform, urceolate, tubular, or rotate; corolla lobes sometimes inflexed in bud; aestivation almost always dextrorse (sinistrorse in some Wrightieae and in Parameria); corolline corona often present, sometimes annular, often petaloid or dissected (Wrightieae), sometimes lower down in corolla tube behind stamen (Apoeyneae, Echiteae), sometimes more than one kind of corona present (mainly Eehiteae); rarely corona lobes on dorsal side of anther (some Malouetieae, Apocyneae); anthers in- eluded or exserted, almost always fertile only in upper part, lower part enlarged and sterile and sides elaborated into lignified guide rails (guide rails poorly developed in some Malouetieae), attached to style head (only very weakly so in some Malouetieae and Wrightieae). Style head variously shaped, epidermis sometimes radially differentiated into 5 secretory and nonseeretory zones, sometimes with collar at base and crest at the apex; stigmatic region on lower cylindrical part on underside; ovary usually apoearpous, sometimes postgenitally syncarpous; ovules mostly numerous per carpel. Nectaries usually present in ring around base of ovary, sometimes coalesced into annulus (absent in most Wrightieae). Fruit usually a pair of slender to stout, thinly to thickly woody, ventrally dehiscent follicles with dry periearp; endocarp not forming a stone; seeds usually numerous, compressed, with coma usually on micropylar end, sometimes with a coma at the chalazal end or at both micropylar and chalazal ends (some Wrightieae and Malouetieae), rarely eeomose (some Malouetieae); endosperm thin, not ruminate. Pollen porate, most commonly with 3-4 apertures; occasionally grains 2-5aperturate or polypantoporate. Steroidal alkaloids or cardenolides often present, indole alka- loids absent. Tribes of Apocynoideae 1. Wrightieae G. Don (1838). Shrubs, trees, or woody climbers. Latex usually milky, sometimes clear. Leaves opposite (alternate in Adenium, whorled in Nerium). Calycine colleters few, alternisepalous, or more numerous. Corolla salveriform to infundibuliform or rarely tubular campanulate; aestivation sinistrorse in Wrightia, Pleioceras, and Stephanostemma; often with conspicuous corona of fiat, petaloid segments in mouth. Stamens included to exserted; lignified guide rails often relatively short. Anthers often only weakly attached to base of style head. Style head usually with basal collar and upper wreath of longer hairs; pollen shed onto upper hair wreath; stigma located beneath basal collar. Disc almost always absent. Ovary apocarpous or, more rarely, syncarpous (secondarily syncarpous in Nerium). Follicles often rather stout, sometimes long and slender, rarely a postgenitally fused capsule (Nerium and some spp. of Wrightia); seeds with a chalazal and/or micropylar coma. Pollen 3--4porate. Secondary compounds cardenolides, x = 10, 11. Distribution: Old World, tropics, rarely subtropics (Nerium temperate). 2. 3. Malouetieae Mull.-Arg. (1860). Shrubs, trees, or woody climbers. Latex usually milky. Leaves opposite (alternate in Pachypodium), often with domatia abaxially in axils of secondary veins with midvein. Calycine colleters usually few, altemisepalous, sometimes several and evenly spread across base of sepal. Corolla salveriform to tubular campanulate; aestivation dextrorse; corona usually absent, but well developed in Malouetia and as inflated hump on dorsal side of anther in Kibatalia. Stamens included or exserted; lignified guide rails usually well developed (absent in Holarrhena). Anthers attached to middle of style head. Style head globose with narrowly conical upper part or broadly fusiform, usually without basal collar and upper wreath; stigmatic region on sides of lower cylindrical part below adnation of anthers; pollen shed onto sides of upper cone; ovary apocarpous; ovules mostly numerous per carpel; nectary disc usually well developed. Follicles mostly long and slender, sometimes stouter; seeds with chalazal and/or micropylar coma, ecomose, or entire seed testa with long hairs. Pollen quite variable: mostly 3-4-porate, but (1-)2(--4) in Mascarenhasia and Pachypodium, 2--4-porate in Malouetia and polypantoporate in Spirolobium. Secondary compounds steroids, x = 11 (9 in Pachypodium). Distribution: Old World (Malouetia also in Central America and South America), tropics. Apocyneae Rehb (1831). Woody climbers, rarely perennial herbs. Latex usually milky. Leaves opposite, rarely whorled or alternate, sometimes with domatia abaxially in axils of secondary veins with midvein and/or cluster of colleters adaxially at juncture of apex of petiole and base of blade. Calycine colleters few and alternisepalous or numerous and spread across base of sepal inside (rarely absent); corolla salveriform, campanulate, or urceolate; corolla-lobe aestivation dextrorse (sinistrorse in Parameria), rarely valvate; corona, if present, mostly as small pouches in petal sinuses, sometimes lower down on corolla tube behind stamens (Apocynum with alternistaminal appendages near base of 4. corolla tube). Stamens usually inserted near the base of the corolla tube, rarely inserted on thickened staminal feet (e.g., Motandra, Aganosma); lignified guide rails long, well developed; main attachment at about middle of style head; base ofthecae normally agglutinated to upper style head as well; style head broadly fusiform, broadest and often with equatorial flange at about middle, normally with neither basal collar nor upper wreath; stigmatic region usually on lower cylindrical region below adnation of anthers. Disc present; ovary apocarpous, postgenitally syncarpous in Beaumontia and Parepigynum, often semi-inferior. Follicles generally thin walled (a stout capsule in secondarily syncarpous species); seeds fiat, linear to ellipsoid or ovate, the testa glabrous or hairy with micropylar (sometimes rostrate) coma. Pollen (2-)3(--4)-porate (polypantoporate in Trachelospermum, Vallariopsis, and Apocynum). Secondary compounds cardenolides or steroidal alkaloids (Elytropus). x = 10, 11 (more rarely 8, 12). Distribution: Old World, tropics (Odontadenia exclusively New World and Apocynum and one sp. of Trachelospermum also New World and there temperate to subtropical). Mesechiteae Miers (1878). Vines, woody lianas, or perennial herbs, the latter sometimes with xylopod. Latex usually milky. Leaves opposite, rarely whorled, often with cluster of colleters adaxially at base of blade (distributed along the length of midrib in some species of Mandevilla), sometimes with domatia abaxially in axils of secondary veins with the midvein. Calycine colleters mostly in alternisepalous groups or in continuous ring, more rarely solitary and episepalous; corolla usually divided into narrow lower tube and expanded upper throat, mostly infundibuliform or tubular campanulate, more rarely tubular or salveriform; corolla-lobe aestivation dextrorse; distinct corona usually absent; stamens mostly inserted at base of throat; lignified guide rails long, well developed; style head with neither basal collar nor upper wreath, with 5 arms, which usually project from lower part (arms forming long ridges for most of length of style 5. III. head in Mandevilla and Macrosiphonia) to which anthers are attached; stigmatic zone con- fined to region on underside or lower region of style head. Disc present; ovary apocarpous. Follicles usually slender; seeds linear, testa glabrous, with micropylar coma. Pollen (2-)3-5(-6)-porate. No information on secondary compounds or chromosome numbers was found in the literature. Distribution: New World, tropics and subtropics. Echiteae Bartl. (1830). Vines or woody lianas, rarely erect shrubs. Latex often clear, sometimes milky. Leaves opposite, rarely whorled. Calycine colleters often one, episepalous, or several and spread across base of sepal, rarely absent; corolla salveriform, infundibuliform, tubular campanulate, campanulate (rotate in Parsonsia, Artia, Ecua, and Thernardia); corolla-lobe aestivation dextrorse, rarely valvate; stamens mostly inserted in upper part of corolla tube (near base in Parsonsia, Artia, Ecua, Pottsia, and Thernardia); anthers often partially to almost completely exserted, with large, lignified guide rails, attached near base of style head; style head cylindrical to narrowly fusiform, broadest and with (usually well developed, often membranous) collar at base and sometimes upper wreath as well; stigmatic zone located on underside of style head beneath collar. Disc present; ovary apocarpous (postgenitally syncarpous in Parsonsia, Artia, Thernardia, Temnadenia, and some spp. of Prestonia). Follicles typically slender (postgenitally fused in Parsonsia, Artia, Thernardia, Temnadenia, and some spp. of Prestonia, but splitting apart at maturity along suture); seeds mostly linear but broadly ovate in Parsonsia and Artia, testa glabrous, with micropylar (often rostrate) coma. Pollen 3-5(8)- porate, x = 6, 7, 8, 9. Secondary compounds cardenolides (known only for Pentalinon). Distribution: New World and Old World, tropics. Periplocoideae R. Br. Ex Endl. (1838). Perennials, woody sometimes tuberous lianas, shrubs to small trees (UtIeria), erect scram- bling or twining herbs or geophytes with underground tuber. Latex milky (clear in Raphionacme namibiana). Leaves opposite, sometimes with cluster of colleters adaxially at juncture of apex of petiole and base of blade. Calyx with usually few adaxial alternisepalous colleters. Corolla rotate to tube rarely longer than lobes; lobes usually spreading, with valvate to dextrorsely imbricate aestivation; corolline corona usually present in sinuses of petals as pair of lobules or single filiform to clavate lobule (usually faintly bifid), often much reduced to rounded bumps or absent (Baroniella, Baseonema, Pentanura). Stamens inserted between base of corolla lobes and base of tube on apex of thickened, ridgelike staminal foot running down corolla tube and mostly fusing at base into solid ring around narrow neck in style above ovaries, apex of foot also sometimes with corona lobe behind point of insertion of filament, this corona lobe sometimes confluent with corolline corona lobes and even more or less in series with them; filaments usually inclined toward style head, usually more or less cylindrical; anthers usually exposed, 4-1ocular, much broader than filament, usually more or less deltoid, nearly horizontal to ascending, with membranous margins neither lignified nor fashioned into guide rails, often laterally adherent or postgenitally fused into more or less umbrellalike structure over style head, adaxially fused to style head usually above its thickest portion (rarely below: Hemidesmus); inner and outer coronal series on stamens lacking. Nectaries on sides of staminal feet or in 5 troughs between staminal feet bearing stamens. Pollen usually shed as T- shaped to rhomboidal tetrads, sometimes gathered into more or less horizontally oriented pollinia (two per locule) not surrounded by waxy outer wall (Atherolepis, Decalepis, Finlaysonia, Gongylosperma, Gymnanthera, Hemidesmus, Meladerma, Streptoeaulon, and Utleria); grains porate, with few to many pores, these scattered or pairwise at the juncture of the monads. Style head broad and flat topped to tapering from broad base into narrow, often bifid apex, with thick and short to long and slender neck joining it to ovaries and 5 stigmatic zones near lower edge between anthers, with 5 vertically oriented grooves between anthers in which translator secreted; translator consisting of spoon- to cornetshaped receptacle above (into which pollen/pollinia deposited), with small sticky viscidium at lower end projecting vertically over edge of style head or horizontally beneath it; ovary apocarpous, semi-inferior, rarely superior (Gymnanthera). Fruit a pair of slender to sometimes very swollen, fusiform, ventrally dehiscent follicles (sometimes one by abortion: Raphionacme) with dry pericarp; seeds numerous, compressed, usually narrowly elliptical in outline, without winglike margin, with micropy|ar coma (extended around entire margin in Finlaysonia and Raphionacme namibiana), endosperm thin. x = 11. Secondary compounds typically cardenolides. Distribution: Old World, dry temperate, subtropics, tropics. IV. Secamonoideae Endl. (1838). Large lianas to twining perennial herbs or small erect shrubs. Latex milky. Leaves opposite, sometimes with few colleters clustered adaxially at juncture of apex of petiole and base of blade. Calyx usually with few adaxial, altemisepalous colleters. Corolla rotate to campanulate or urceolate; lobes mostly with dextrorsely contorted or valvate aestivation (but sinistrorsely contorted in Genianthus); eorolline corona consisting of 5 fleshy ridges radiating out along in- ner surface of corolla lobes close to and nearly parallel to margins and meeting in sinuses where they sometimes form pouch. Stamens inserted on staminal tube around ovaries and adaxially fused to sides of style head (usually in its cylindrical portion); anthers 4-1ocular, sessile on apex of staminal tube, sometimes partly hidden by corona lobes, usually more or less deltoid, erect to more or less horizontal, rarely with elongated appendages (Calyptranthera), lateral margins, often covered with hairs or with marginal cilia, with well-developed, lignified guide rails below fertile part; staminal tube with simple to complex corona attached dorsally (rarely absent) and without clear vascularization: outer corona rarely present as small, continuous ridge running beneath guide rail and below anthers; inner corona arising at or slightly below base of anthers, sometimes consisting of two series of lobes (Genianthus). Nectaries consisting of 5 vertical altemistaminal troughs behind guide rails on staminal tube. Pollen inaperturate, gathered into minute pollinia, two per locule, not surrounded by waxy outer wall; pollinia more or less erect, forming above guide rails, more or less ellipsoidal, without insertion crest, sometimes adjacent pairs adhering to form single body. Style head very variably shaped, with thick cylindrical part just above ovaries widening slightly toward apex, narrowing above this into usually bifid apex, which is sometimes much inflated, occasionally long and slender, with 5 stigmatic zones located on sides of lower cylindrical part, probably just below thickest area behind guide rails, secreting translator just above each guide rail; translator consisting of small, porous, cliplike, brownish corpuscle with flanks and sometimes with floor, sometimes with one or two caudicles (if two then each attaching a pair of pollinia to corpuscle) (Genianthus, Secamonopsis, and some species of Secamone); ovary apocarpous, semi-inferior. Fruit a pair of slender to stout, fusiform, ventrally dehiscent follicles with dry pericarp; seeds numerous, compressed, more or less elliptical in outline, without winglike margin, with micropylar coma, endosperm thin. No information on chromosome numbers found in literature. Secondary compounds (reported only for Menabea = Pervillea) are cardenolides. Distribution: Old World, temperate to tropics. V. Asclepiadoideae R. Br. Ex Burnett (1835). Trees to shrubs or herbs, succulents, or small geophytes (rarely annual), with milky or clear latex. Leaves opposite (rarely whorled), sometimes reduced to small rudiment or occasionally a spine, often with cluster of colleters adaxially at juncture of apex of petiole and base of blade. Calyx usually with few to many adaxial, more or less alternisepalous colleters. Corolla rotate to tubular; lobes valvate to imbricate; corolline corona rare in sinuses of lobes (except in some Ceropegieae and Gonolobinae, where present as annulus). Stamens inserted on staminal tube around ovaries and adaxially fused to style head below its thickest portion near its base; anthers 2-1ocular, sessile on apex of staminal tube, spreading, erect, or horizontal (rarely descending), deltoid, subquadrate, with or without sterile, membranous, apical appendage, lateral margins sometimes becoming membranous after dehiscence, with welldeveloped, lignified guide rails alongside or below fertile part; staminal tube with simple to complex corona attached dorsally (rarely absent) and without clear vascularization: outer corona frequently present at or near base, of 5 free lobes to fused into tube; inner corona usually present at or just below bases of anthers at apex of staminal tube, usually of 5 free lobes. Nectaries consisting of 5 vertical alternistaminal troughs behind guide rails on staminal tube. Pollen gathered into pollinia, one per locule, with waxy outer wall, often with hyaline insertion crest. Style head broad, often with flat or concave apex (rarely conical to slenderly conical), sessile on top of ovaries to tapering gradually with narrow neck into them, with 5 stigmatic zones located on sides of lower cylindrical part behind guide rails, secreting translator just above each guide rail; translator consisting of hard, cliplike, brown to black corpuscle, mostly with flanks and floor, with two flexible, translucent caudicles (rarely absent in some Marsdenieae), each of which attaches one pollinium to corpuscle; ovary apocarpous, mostly superior. Fruit a pair (often one by abortion) of slender to stout fusiform, more or less obclavate (rarely very stout to more or less spherical), ventrally dehiscent follicles with dry pericarp; seeds nu- merous, compressed, more or less elliptical in outline, often with winglike margin, mostly with micropylar coma (rarely absent or present around seed margin), endosperm thin. x = 11 (rarely 10, 9). Distribution: cosmopolitan, temperate to tropics. Tribes of Asclepiadoideae 1. Marsdenieae Benth. (1868). Herbs, vines, lithophytes, or epiphytes (these usually leaf succulents), rarely stem succulents, with milky, yellow, or clear latex. Corolla rotate to urceolate; lobes with valvate to dextrorsely imbricate aestivation; corolline corona rare (e.g., Sarcolobus, Marsdenia), consisting of ridges near sinuses of petals running down corolla tube to near base. Anthers erect to more or less horizontal, often with apical appendage, but this never constricted at base, with guide rails below fertile part (more or less poorly developed in Fockea). Outer corona near base of staminal tube, rarely ringlike or cupular around whole column (Gunnessia), mostly absent; inner corona usually of 5 free small to large entire lobes, rarely absent (Rhyssolobium). Pollinia erect to horizontal, mostly more or less ellipsoidal, occasionally with hyaline insertion crest along inner or lower edge (Micholitzia) through which pollen tubes emerge. Style head broad, with thick convex to conical apex, sessile on top of ovaries; corpuscle usually with flanks and floor (occasionally very fragile and lacking floor: Cibirhiza, Fockea, Gongronema); caudicles normally present (more or less absent in Cibirhiza, Fockea). Follicles (often only one by abortion) slender to fusiform obclavate (rarely nearly spherical), occasionally ornamented with longitudinal ridges on exterior; seeds without winglike margin, with coma (absent in some Sarcolobus, right around seed in Fockea sinuata), x = 11. Characteristic secondary compounds are "Asclepiadaceae bitter principles" (glycosides). Distribution: cosmopolitan, mainly subtropical to tropical. 2. Ceropegieae Orb. (1843). Herbs (rarely annuals: Conomitra), vines, or geophytes with subterranean tubers or stem succulents, with clear latex, rarely milky (especially Heterostemma). Leaf frequently reduced to minute, scalelike structure or spine, rarely with few colleters at juncture of apex of petiole and base of blade (Ceropegia, Heterostemma). Corolla rotate to variously tubular (urceolate to cylindrical; e.g., Ceropegia, Echidnopsis, Stapeliopsis), often fleshy, frequently with 3. fleshy annulus around mouth of tube, often ornamented with papillae, hairs, or cilia; lobes with valvate aestivation, sometimes remaining fused at apices; corolline corona rarely present in sinuses of corolla lobes (Leptadenia). Anthers mostly hidden by corona lobes, erect to horizontal (rarely descending), sometimes lateral margins becoming membranous after dehiscence (rarely with membranous apical appendage: Caralluma), with guide rails below fertile part. Outer corona from 5 freespreading lobes to partially or entirely fused into cup around column; inner corona usually of 5 free-ascending to erect lobes. Secondary nectaries some- times on corona lobes. Pollinia erect to horizontal (rarely descending toward center of flower, e.g., Tavaresia), nearly spherical, ellipsoidal to D-shaped in outline and then strongly dorsiventrally flattened, with hyaline insertion crest along upper or outer margin through which pollen tubes emerge. Style head broad, with flat to concave (rarely convex or beaked) apex, usually much broader than tall, mostly sessile with ovaries somewhat embedded into indented base but occasionally tapering below via narrow neck into ovaries (e.g., Orbea, Macropetalum); corpuscle with flanks and floor and two spreading lateral wings to underside of which caudicles are attached. Follicles (sometimes only one by abortion) slender to stout fusiform; seeds usually surrounded by winglike margin; coma present, x = 11. Characteristic secondary compounds are "Asclepiadaceae bitter principles" (glycosides). Distribution: Old World, arid temperate, subtropics, tropics. Asclepiadeae (R. Br.) Duby (1828). Herbs, trees (up to 6 m, Calotropis), vines, geophytes with subterranean tubers, occasion- ally succulents, with milky (rarely clear or yellow) latex. Leaves often with cluster of colleters adaxially at juncture of apex of petiole and base of leaf blade. Corolla rotate to occasionally tubular; lobes with valvate to imbricate aestivation; corolline corona rare, in sinuses of lobes (Araujia sericifera) or annular in Gonolobinae. Anthers generally erect to spreading, with deltoid apical appendage distinctly constricted at base, with guide rails along- side fertile part (rarely below: Karimbolea, some species of Tylophora, most Gonolobinae). Outer corona from 5 to 20 (Eustegia, Emicocarpus) minute, free, spreading to erect lobes to partially or entirely fused into cup, together with or free from inner lobes around column or annular (Gonolobinae), rarely absent; inner corona usually of 5 massive, free, often channeled lobes, often with additional lobules on adaxial surface (rarely partially fused with corolla, Parapodium) to small and adpressed to backs of anthers or absent (Pleurostelma, Stephanuso Microloma). Pollinia pendulous or rarely erect (Karimbolea), more or less horizontal (some species of Tylophora), small and more or less ellipsoidal to long narrow and dorsiventrally flattened, rarely with hyaline insertion crest along inner edge, Pergularia; on upper margin near attachment ofcaudicles, Gonolobinae; upper edge in some Schizoglossum or with caudicles attenuated into small apical spike (Oncinema), pollen tubes emerging through inner, upper edge or one concave face (Gonolobinae). Style head broad, with fiat to concave (sometimes conical to slenderly conical) apex, tapering below into narrow neck above ovaries (more or less sessile in Eustegia, Emicocarpus); caudicles frequently with projecting hooks and ridges assisting in insertion of pollinium in guide rail; ovary apocarpous, mostly superior. Follicle (usually one by abortion) often extremely swollen (Araujia, Calotropis), rarely spherical, more usually fusiform obclavate, frequently ornamented with spine- like processes or protuberances or longitudinal ridges on exterior; seeds more or less elliptical in outline, without winglike margin, with coma (absent in Emicocarpus). x = 11 (rarely 10, 9). Secondary compounds are "Asclepiadaceae bitter principles" (glycosides), more rarely car- denolides. Distribution: cosmopolitan, temperate to tropics. REPRESENTATIVE SPECIES Rauvolfioideae Alstonia scholaris (L.) R. Br. Medium to large tree, to about 40 m high with a somewhat tessellated corky grey to grey-white bark. The boles of larger trees are strongly fluted to 10 m. The outer blaze is cream to yellowish in colour with abundant, milky latex that flows rapidly when cut. Leaves in whorls of 4-8 in the upper axils; leaf stalks 1-1.5 cm long, the lamina obovate to elliptical or elliptical-lanceolate, glabrous or sparsely hairy, tapering towards the base, 11.5-23 x 47.5 cm. Upper surface is dark green, the lower greenwhite with 25-40 pairs of lateral veins on each side of the midrib and 2-6 mm apart. The tip of the leaf is rounded or shortly pointed, tapering towards the base. The inflorescence is a much-branched terminal panicle, up to 120 cm long; flowers 7-10 mm long white, cream or green; the tube hairy; lobes sparsely or densely pubescent, 1.5-4 mm long, the left margins overlapping; strongly perfumed. Fruit a pendulous, two-lobed, dehiscent follicle, brown or green, dry or woody, spindle-shaped, 15-32 cm long, 4-6 mm in diameter, containing numerous flat, oblong, brown seeds, 4-5 x 0.9-1.2 mm, with a tuft of hairs 7-13 mm long at each end. The seed does not taper to a point at either end. Etymology. Alstonia Dr. C. Alston, professor of botany, Edinburgh University. scholaris use of wood for schoolboards in Myanmar. Uses. The latex provides a good quality chewing gum. A. scholaris has been recommended as a fuelwood species for the patana lands of Sri Lanka. Bark yields a fibre, and the wood is regarded as suitable for pulp and paper production. A. scholaris is the most important source of pulai timber. The density of the wood is 270490 kg/cubic m at 15% mc. Heartwood cream to pale yellow, sapwood wide and visually indistinct from the heartwood. Often has strong odour and a bitter taste. It is used for pattern making, corestock, plywood, carving and mouldings. The wood is also used for making coffins in Sri Lanka and school boards in Myanmar. Flowers of A. scholaris yield an essential oil. Australian aborigines used the bark for treatment of abdominal pains and fevers, the latex for neuralgia and toothache. In India, the bark is used to treat bowel complaints and has proved a valuable remedy for chronic diarrhoea and the advanced stages of dysentery. Leaves used for treating beriberi, dropsy and congested liver. Wood charcoal is used as gun powder. The tree is sometimes planted as an ornamental. In a study of the ethnobotany of the Nagas of Nagaland in northeast India, A. scholaris was amongst the native plants used in magico-religious beliefs. Distribution. Native to Australia, Bangladesh, Brunei, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Solomon Islands, Sri Lanka, Thailand, Vietnam. Exotic to Taiwan, Province of China, US. Catharanthus roseus L. Shrub or herb (15–)30–100(– 200) cm high, erect or decumbent; base usually woody with pale gray bark; latex white. Stems terete, longitudinally ridged or narrowly winged, green or dark red, pubescent at least when young. Leaves decussate, stipulate; stipules 2–4, acuminate, <1(–2) mm long; petiole (1–)3–11 mm long, narrowly winged, green or red; blade (1.0–)2.5–9.0 x (0.6–)0.8–4.0 cm, elliptical to obovate, oblong, or rarely lanceolate; apex mucronulate, rounded to acute or obtuse; base cuneate to attenuate; margins entire, sometimes ciliate; venation pinnate with 7–11 pairs of lateral veins; both surfaces dark green with pale lateral veins in living material; petiole, stipules, and blade pubescent or glabrous. Inflorescences axillary; flowers paired on peduncles 1–4 mm long or solitary, subsessile; inflorescence pubescent or glabrous. Sepals 5, 2–6 mm long, basally connate, narrowly triangular, subulate, pubescent or glabrous. Corolla salverform; tube usually greenish, (1.5–)2.2–3.0 cm long, externally glabrous or pubescent, internally pubescent with strigose rings below mouth and below insertion point of stamens; lobes 5, pink to white or reddish purple, often with a darker or yellowish center, (0.5–)1.0–2.8 cm long, broadly obovate with narrowed base and rounded, usually cuspidate apex, sometimes pubescent. Stamens 5, inserted in widest upper portion of corolla tube; anthers subsessile, 2.2–3.0 mm long, narrowly triangular, included within corolla tube. Gynoecium of 2 free carpels below, syncarpous above; ovary pubescent or glabrous; single style 15–24 mm long; terminal pistal head bearing a recurved basal veil, pubescent ring, and pubescent cylinder with bilobed stigma; disk of 2 glands, 2–4 mm long, alternating with carpels. Fruit 2 follicles, (1.2–)2.0–4.7 cm long, linearterete, erect, longitudinally ridged, green, pubescent or glabrous; seeds numerous, black, 1–3 mm long, irregularly oblong. Etymology. Catharanthus perfect-flower, kaqaroj-anqoj. roseus rose-like, rose-coloured. Uses. Madagascar periwinkle has been widely distributed for long enough that it has gained medicinal uses for a variety of purposes far from its native land of Madagascar. Most notably, the plant is or has been used for diabetes in places as diverse as Madagascar, South Africa, Jamaica, Suriname, Vietnam, the Philippines, India, and Australia. Studies using animal models of diabetes have found that crude extracts of Madagascar periwinkle do reduce blood glucose levels. The mechanism of action of this activity is not understood, although the alkaloids now used to treat leukemia were discovered by researchers investigating the plant’s antidiabetic potential. High blood pressure is another condition sometimes treated with Madagascar periwinkle; as noted under “Toxicity,” large doses of the plant can cause hypotension, indicating the plausibility of this use. Although two of the bisindole alkaloids from Madagascar periwinkle (vincristine and vinblastine) are used as pharmaceutical drugs to treat leukemia and Hodgkin’s disease, crude extracts of the plant do not contain enough of these compounds that they could be used as effective cancer treatments (if they did, they would be extremely toxic), and there is little or no folk use for similar purposes. Distribution. Native to Madagascar, the Madagascar periwinkle has been spread worldwide as a cultivated ornamental. It may now be found naturalized in almost every tropical and subtropical region of the world, occurring on every continent except Antarctica and on many islands. Willughbeia anomala Markgr. Woody climber to 20 m. Branchlets glabrous or sparsely rufous pubescent; branches lenticellate. Leaves: petiole 0.7-1.6 cm long; blade elliptic oblong, 6-19.5 by 2.1-4.9 cm, 2.6-4.2 times as long as wide, apex acuminate, base cuneate, papery to subcoriaceous, glabrous or with a few brown hairs on midrib beneath, dull ochre beneath when dry, 12-23 pairs of secondary veins at 55-80°, reaching margin, tertiary venation faint and perpendicular to secondary veins, occasionally with 1 intercalated vein. Inflorescence axillary and terminal, axis longer than subtending petiole, to 4 cm long; 4-19 flowers per inflorescence; axes rufous pubescent; pedicels 1.7-3.8 mm long. Sepals ovate, thick, 1-1.4 mm long, lobes 0.50.7 by 0.3-1 mm, 0.6-2 times as long as wide, apex rounded, rufous pubescent, ciliate. Corolla tube cylindrical, 10-14 mm long, c. 10 times as long as calyx, rufous puberulent in 5 rows down tube or glabrous, pubescent in throat; lobes 6-8.2 mm long, oblong or elliptic, ciliate or not. Stamens inserted at 1.1-1.7 mm from corolla base which is 0.11-0.14 of tube length; filaments 0.4-0.8 mm long; anthers 1.3-1.4 by 0.5 mm. Ovary 0.6-0.9 mm; style 0.1-0.2 mm long, impressed on ovary; style head 0.3-0.4 mm long, apex 0.5-0.6 mm long. Fruit spherical, 6.6-8 cm diameter. Seeds c. 2.6 by 1.5 by 1.3 cm. Uses. To treat shingles (kayap) and other skin diseases. The white latex from the fresh plant is applied externally. Distribution. Borneo, Malesia, Philippines. Tabernaemontana pandacaqui Lamarck. Shrubs or small trees 1-14 m tall. Branchlets pubescent to glabrous. Petiole 0.3-2 cm; leaf blade elliptic or narrowly so, 3-25 X 1-10 cm, sometimes pubescent abaxially, apex acuminate, caudate, or obtuse; lateral veins 4-16 pairs. Cymes 3-16 cm. Flower buds with a broadly ovate head, apex rounded or obtuse. Corolla white, tube 0.8-2.2 cm; lobes obliquely oblong, falcate, 0.6-1.9 cm. Stamens inserted at or above middle of corolla tube. Ovary glabrous. Follicles obliquely ellipsoid, 1.2-7 X 0.5-3 cm, apex beaked or rounded. Fl. May-Jul, fr. Jul-Nov. Use. All parts of the plant are poisonous. The roots, leaves, and flowers are used in Guangdong and Guangxi against snake and scorpion poisoning. In modern medicine, the roots are used to treat hypertension, headache, and scabies. Distribution. Open forests, brushwoods; low to middle elevations. S Guangdong, Taiwan, S Yunnan [Indonesia, Malaysia, Philippines, Thailand; Australia, Pacific Islands]. Melodinus cochinchinensis (Loureiro) Merr., Lianas stout, to 10 m, glabrous except for inflorescences. Branches dark brown. Petiole 6-10 mm; leaf blade elliptic or narrowly so, 6-19 X 2.2-6.5 cm, papery, base cuneate, apex acute or acuminate; lateral veins numerous, convergent, conspicuous. Cymes paniculate, terminal, 3-branched, 4-5.5 cm, minutely pilose; bracts and bracteoles minute. Pedicel short. Sepals orbicular or broadly elliptic, ca. 2 mm, ciliate, apex subacute to rounded. Corolla white; tube ca. 6 mm, pilose except at base; lobes ovate, ca. 3.5 mm; corona large, lobes 2cleft, villous. Ovary glabrous. Style ca. 3 mm. Berries narrowly ellipsoid, ca. 9 X 5 cm. Seeds oblong or ovate, ca. 1.3 cm. Fl. Apr-May, fr. Sep-Nov. Use. Have long been used in folk medicine for the treatment of various ailments such as meningitis in children and rheumatic heart diseases, hernia, infantile malnutrition, dyspepsia and testitis Distribution: Montane forests; 800-2800 m. S Yunnan [Myanmar, Thailand, Vietnam] Apocynoideae Wrightia antidysenterica (L.) R. Br. Trees or shrubs with latex. Leaves opposite, petiolate; glands axillary. Cymes terminal or subterminal, dichasial, few to many flowered. Sepals quincuncial, with 5-10, basal, scalelike glands inside. Corolla salverform, funnelform, subrotate, or rotate, tube cylindric to campanulate; lobes overlapping to left; corona ligulate, fringed, or cup-shaped, entire or subentire at apex, shallowly or deeply divided, sometimes absent. Stamens inserted at middle, apex, or rarely base of corolla tube; anthers sagittate, connivent and adherent to pistil head, exserted, spurred at base; disc absent. Ovaries 2, distinct or connate; ovules numerous in each locule. Style filiform; pistil head ovoid, usually dilated at base. Follicles 2, connate or divaricate. Seeds narrowly fusiform, with an apical coma directed toward fruit base, beakless. Uses. The bark possesses anti-microbial and antiinfammatory properties and therefore the juice extracted from it is administered for mouth sores. The leaves are used in treating several skin disorders, psoriasis, nonspecific dermatitis etc. The bark is used as an adulterant for the well-known drug, Holarrhena antidysenterica Distribution: tropical Africa, Asia, Australia; Apocynum venetum L. Stems to 4 m tall, glabrous except for inflorescences; branches and branchlets whitish gray, terete, finely striate. Leaves usually opposite; petiole 3-6 mm; leaf blade narrowly elliptic to narrowly ovate, 1-8 X 0.5-2.2 cm, base rounded or cuneate, margin denticulate, apex acute or obtuse, mucronate. Sepals narrowly elliptic or narrowly ovate, ca. 1.5 mm. Corolla purplish red or pink; tube campanulate, 6-8 mm, granulose; lobes 3-4 mm. Disc fleshy, 5-lobed; lobes rounded, base adnate to ovary. Follicles slender, 8-20 cm X 2-3 mm. Seeds ovoid or ellipsoid, 2-3 mm, coma 1.5-2.5 cm. Fl. Apr-Sep, fr. Jul-Dec. 2n = 22. Uses. The strong bast fibers obtained from the inner bark are used in making cloth, strings, sails, fishing nests, and high-quality paper. The leaves yield up to 5% gum, which is used for making rubber, and a medicine used as a sedative and to treat hypertension. The species has fragrant flowers and is grown as a honey plant. Distribution. Salt-barren zone, desert margins, alluvial flats, riversides. Gansu, Hebei, Henan, Jiangsu, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shandong, Shanxi, Xinjiang, Xizang [India, Japan, Mongolia, Pakistan, Russia; SW Asia, Europe]. Secamonoideae Secamone elliptica R. Br. Twigs, petioles and leaves produce a milky exudate. Leaf blades about 25-55 x 828 mm, petioles about 2-9 mm long. Small reddish glands visible on the twigs close to the point of attachment of the petioles. Sepals about 1.25-1.5 x 1 mm. Petals about 2.5 x 1.5 mm. Stamens fused together to form a corona and column. Anthers about 1 x 0.75 mm. Pollinia two per locule. Fruits usually paired, each fruiting carpel oblanceolate to fusiform, about 60-70 x 5-9 mm, flat on one side. Seeds numerous, eachseed flat, about 7 x 2 mm. Plume about 25-30 mm long, attached to one end of the seed. Embryo about 5-6 mm long. Cotyledons elliptic, longer and wider than the radicle. Uses. Larval plants. Distribution. Occurs in Australia and southwards to north-eastern Australia. Altitudinal range in northern Australia from near sea level to 750 m. Grows in vine thicket and monsoon forest. Also occurs in Malesia and the Pacific islands. Asclepiadoideae Hoya carnosa (Lf.) R.Br. Shrubs epiphytic, climbing, glabrous except for inflorescences. Stems robust, to 6 m, pale gray, smooth. Petiole 1-1.5 cm; leaf blade broadly ovate-cordate to ovate-oblong or elliptic, 3.5-13 × 3-5 cm, base rounded to shallowly cordate, apex obtuse or short acuminate; lateral veins ca. 4 pairs, obscure. Pseudumbels extra-axillary, globose, ca. 30flowered, pubescent; peduncle ca. 4 cm. Pedicel 2-4 cm. Corolla white, sometimes with a pink center, rotate, 1.5-2 cm in diam.; lobes triangular, densely papillate inside, margin recurved, apex reflexed. Corona lobes stellate spreading, outer angle acute, middle ridge prominent, margin strongly reflexed and enclosing a hollow space at base, inner angle acute, incumbent on anthers. Stigma head obtuse or obscurely apiculate. Follicles linear-lanceolate, 6-10 × 0.5-1.5 cm. Seeds ca. 5 × 1 mm; coma ca. 2.5 cm. 2n = 22*. Uses. A common ornamental. Distribution. Hoya carnosa is one of the many species of Hoya that are native to Eastern Asia and Australia. Asclepias tuberosa L. Herbaceous perennials. Calyx deeply five-parted; corolla deeply five-parted, valvate in aestivation, finally reflexed; staminal corona fiveleaved, leaflets rolled into a hoodshape, a hornlike process standing out from the base of each; anthers in a five-angled, truncate mass; pollen in masses of five distinct pairs, pendulous; fruit in two ventriocous follicles; seeds numerous, flat, umber-colored, with an abundant white, long, silky coma. Stem ascending, sometimes almost decumbent, with spreading branches at top, hairy. Leaves alternate, scattered, upper ones sessile, acute, obtuse at base, oblong, two to four inches by six to ten lines. Flowers in numerous, large, corymbed umbels, terminal; with hoods bright orange, oblong, narrow; appearing in July and August. Follicles erect, lanceolate-pointed. Uses. The root of this plant is probably one of the most reliable and serviceable relaxing diaphoretics in the whole Materia Medica. It diffuses itself with only moderate rapidity, but maintains its influence with considerable pertinacity. Its principal action is upon the sweat glands, at the same time that it relaxes the capillaries and thereby relieves the heart and arteries. It also exerts a decided impression upon the serous tissues, especially the pleurae and peritoneum; the mucous membranes of the lungs and bowels are also influenced by it; and its general action gives a peculiar and valuable relief to acute arterial and nervous excitements. The chief employment of this agent is in febrile and inflammatory affections, where the perspiration needs to be decidedly promoted, and excitement of the heart relieved by a full outward determination of blood. It secures a slow, steady, and free perspiration, at the same time suitably diminishing excessive heat of the surface; which action renders it highly serviceable in typhus, scarlet, bilious, puerperal, lung, rheumatic, and other forms of fever, with a hot skin and rigid pulse. Measles and catarrhal fever may be added especially to this list; and so great is its service in pleurisy, that Apleurisy root is one of the most popular of its names among the people. In acute dysentery, with fever and tormina, it secures that free circulation to the surface which affords great relief to the bowels; and in the acute stages of inflammation of the womb, bladder, and kidneys, it is of equal advantage. In all these cases its use is followed by not only an increased perspiration and softening of the pulse; but the action of the kidneys becomes better, the mucous surfaces act more firmly and naturally, and the nervous system obtains a soothing impression that is very desirable. General as the action of this agent thus is, it is yet rather slow; and its influence is so void of stimulation, that the physician will be disappointed if he look for sudden and powerful effects from it. Its persistency and mildness, together with its certainty, are what make it so useful. Most commonly it is combined with some diffusive and more prompt stimulant, especially with about one-fourth its own weight of ginger or polemonium. There is a peculiar insipidness about the taste of this asclepias, which is well covered by the ginger. The fresh root has a rather mawkish, nauseating taste. Distribution. Ontario to Newfoundland; New England south to Florida; west to Texas; north through Colorado to Minnesota. REFERENCES Apocynum venetum L. (n.d.). Retrieved September 11, 2015 from http://www.efloras.org/florataxon.aspx?flora_id=2&ta xon_id=200018353 Asclepias tuberosa White Root, Pleurisy Root, Butterfly Weed. (n.d.) Retrieved September 11, 2015 from http://www.henriettesherb.com/eclectic/cook/ASCLEPIAS_TUBEROSA.ht m Catharanthus roseus Madagascar Periwinkle. (n.d.) Retrieved September 11, 2015 from http://eol.org/pages/581125/details#comprehensive_de scription. Endress, M. (2004). Apocynaceae: Brown and Now. Telopea. 10 (2), 525-541. Endress, ME. & Bruyns, PV. (2000). A Revised Classification of the Apocynaceae s.l. The Botanical Review. 66 (1), 1-56. Hoya carnosa. (n.d.) Retrieved September 11, 2015 from http://www.efloras.org/florataxon.aspx?flora_id=3&ta xon_id=134988 Melodinus cochichinensis. (n.d.). retrieved September 11, 2015 from http://www.efloras.org/florataxon.aspx?flora_id=2&ta xon_id=210001260 Orwa et al. (2009). Alstonia scholaris R. Br. Apocynaceae. Retrieved September 11, 2015 from http://www.worldagroforestry.org/treedb/AFTPDFS/A lstonia_scholaris.PDF Secamone elliptica. (n.d.) Retrieved September 11, 2015 from http://keys.trin.org.au/key-server/data/0e0f0504-0103430d-8004060d07080d04/media/Html/taxon/Secamone_elliptica. htm Sennblad, B. & Bremer, B. (2002). Classification of Apocynaceae s.l. According to a New Approach Combinig Linnean and Phylogenetic Taxonomy. Syst.Biol. 51 (3), 389-409. Tabernamontanae. (n.d.) Retrieved September 11, 2015 from http://eol.org/pages/2899689/details Willughbeia anomala.(n.d.).Retrieved September 11, 2015 from http://portal.cybertaxonomy.org/floramalesiana/node/2715