zyxw zyxw zyxwvu zy zyx zyxwv Remarks on three Hypobathreae (Rubiaceae) from Rodrigues, Seychelles and Sri Lanka Deva D. Tirvengadum and Elmar Robbrecht Tirvengadum, D. D. & Robbrecht, E. 1985. Remarks on three Hypobathreae (Rubiaceae) from Rodrigues, Seychelles and Sri Lanka. - Nord. J. Bot. 5 : 455461. Copenhagen. ISSN 0107-055X. Ramosmania (from Rodrigues Island, Mauritius), recently described by Tirvengadum & Verdcourt as a genus of uncertain position, is here shown to belong to the tribe Hypobathreae (subtr. Hypobathrinae). It is related to Morindopsis Hook. f. Two other rubiaceous genera previously placed in the tribe Gardenieae, viz. Paragenipa Baillon, from the Seychelles, and Nargedia Beddome, from Sri Lanka, are also shown to belong to the tribe Hypobathreae. Paragenipa cervorum Baillon being conspecific with Randia Iancifolia, (Boj. ex Bak.) Hemsl. the new combination Paragenipa lancifolia is made. From the anatomical point of view, Paragenipa is interesting on account of its remarkable seed-coat (exotesta with several layers of fibres), unusual in most Rubiaceae. Nargedia is the first representative of the subtribe Lamprothamninae outside Africa. D . D . Tirvengadum, Museum National dHistoire Naturelle, Lab. de Phankrogamie, 16, rue Buffon, F-75005 Paris, France. E . Robbrecht; Nationale Plantentuin van Belgie, Domein van Bouchout, 8-1860 Meise, Belgium. Introduction In the classical systems of the Rubiaceae (Hooker 1873, Schumann 1891), the Gardenieae are an overrated and artificial tribe assembling genera with contorted corollalobes, many ovules per locule and fleshy fruits. Since Bremekamp’s (1934, p. 6-7) criticism of its delimitation, a more natural definition of the tribe is slowly crystallizing. Recently, one of us (Robbrecht 1980a) has proposed a new tribe, Hypobathreae, in order to accomodate about twenty genera previously ascribed to the Gardenieae. Besides these changes at tribal level, significant infratribal improvements have been made. Keay (1958) has partially delimited the Randia-Gardenia complex for Africa and Tirvengadum (1978, 1982) has, on the basis of hitherto neglected generic characters such as the shoot-sequence system and the structure of the testa cells, proposed a new circumscription of tribe Gardenieae for South and South East Asia and is currently pursuing his monographic research on that 0 NORDIC JOURNAL OF BOTANY NORD. J. BOT. 5 : 455461, TROP 110 30 Nord. J. Bot. 5 ( 5 ) 1985 tribe for tropical Asia. Those two contributions have led to a better comprehension of the tribe, particularly in complex groups and among poorly defined genera of the Old World tropics. In this paper, three imperfectly known or poorly collected taxa previously placed in the Gardenieae from the Indian Ocean islands of Rodrigues (Mauritius), Seychelles and Sri Lanka, are discussed and their tribal disposition established. Material and methods The observations for this study were carried out in AAU, MAU and P (D.T.) and BR (E.R.) and are based on herbarium material. Visits to Kew and L were made by both of us. Field work (D.T.) was carried out in Sri Lanka (Oct. 1977), in Rodrigues (Jul. 1980) and in the Seychelles (Jan. 1980, Aug. 1981). Herbarium abbreviations are in accordance with Holmgren et al. (1981). zyxwv 455 zyxwvutsrqp zyxwvuts zyxwvutsrqp zyxwvutsr The following specimens were used for detailed observations: Ramosmania heterophylla (Balf. f.) Tirvengadum & Verdcourt Rodrigues, s.I., Dec. 1874, Balfour s.n. (K): flowers, pollen and young fruits - same collection, (P): flowers and young fruits. - Paragenipa lancijolia (Boj. ex Bak.) Tirvengadum & Robbrecht - Seychelles, s.1. (wrongly labelled from Mauritius), 1858, Grey s.n. (K): flowers - Seychelles, s.d., Wright 45 (K): flowers - Maht, 18 Sept. 1976, s. A. Robertson 2275 (P, SEY) : fruits - ibid., 5 Oct. 1970, Schlieben 11687 (K): fruit - ibid., July/Aug. 1902, Thomasset 72 (K): Pollen - ibid., July/Aug. 1902, Thomasset 90 (K): flowers and fruits - Morne Seychellois National Park, 6 Jan. 1980, Tirvengadum & Chong Seng 898 (P): young fruits - Sans Souci, 14 Aug. 1983, Chong Seng s.n. (P): mature flowers and young fruits. D Nargedia macrocarpa Bedd. Lanka, s.I., Thwaites 2709 (P, PDA): young fruits - Kanneliya Forest Reserve, 9 June 1973, Kostermans 24996 (L): young fruits - ibid., 8 Oct. 1974, Tirvengadum & Waas 691 (P): young fruits. - Sri A pollen slide of Paragenipa lancifolia, prepared by Mrs M. Harley and Dr I. K. Ferguson, was obtained from the Jodrell Anatomy Laboratory, Kew. Fruits and seeds were obtained from dried herbarium specimens. Permanent slides were made by mounting pieces of the peeledoff testa and hand-made sections of the seeds in Hoyer's gum. The testa cells were observed in surface view and in cross-section under an ordinary light microscope and also under a scanning electron microscope. Ramosmania Tirvengadum & Verdcourt Nord. J. Bot. 2: 326, figs. 1-4, 1982 - Type: Ramosmania heterophylla (Balf. f.) Tirvengadum & Verdcourt. In the protologue of Ramosmania, a monospecific endemic genus based on Randia heterophylla Balf. f., the genus has been excluded from the Gardenieae. A de- Fig. 1. Ramosmanza heterophylla - A. Immature fruit (X3). B. Fruit in longitudinal section (X3). - C. Cross-section of fruit ( x6) . - D . Immatureseed (X37). -AllfromBalfours.n.,Dec. 1874 (P). tailed investigation was made, but without attempt to settle the question of its tribal disposition. All features of the genus, especially inflorescences, pollen, fruits and seeds fit well the concept of the Hypobathrinae of the tribe Hypobathreae; within the subtribe it is a near relative of Morindopsis Hook. f. This latter Asiatic genus shares the characteristic paired, opposite, oblique, long peduncles of the inflorescences (condensed and involucred), very often fused over a certain distance with the stem; both genera have also in common large, elongated, ribbed fruits with many elon- Tab. 1. Comparison of Ramosmania and Morindopsis for some important characters. Ramosmania Morindopsis Shrubs Trees Stipules forming a short subtruncate sheath when adult, acuminate on the young stems Stipules not sheathed (slightly connate at base), ovate-lanceolate, acuminate Leaves heterophyllous Leaves homophyllous Inflorescence 1-5-flowered Flowers collected into a small head of 5-12 flowers solitary) Flowers fairly conspicuous, monoecious, 5-merous Flowers small, dioecious, 45-merous Corolla tube 10-20 mm long Corolla tube 2.5-3 mm long Endemic to Rodrigues (Mauritius) Confined to South East Asia 456 ( 0 rarely zyx Nord. J. Bat. 5 ( 5 ) 1985 zy zy zyxw I 5 6 8 zyxwvutsrqpon zy zyxwvuts Fig. 2. Purugenipu luncifoliu - 1. Flowering habit. - 2. Flower bud. - 3. Mature flower after anthesis. - 4. Corolla opened to show anthers and hairy base of limb inside. - 5. Anthers, front and side view. - 6. Style slightly hirsute just above base and bifid stigma. - 7. Vertical section of the ovary, disc and calyx. - 8. Transverse section of the ovarv. - 9. Fruitine habit. - 10. Youne fruit. - 11. Gross-section of fruit. - 1. FromThornasset s.h. (K); 2-8 from A. Grey 1858(K); cafyx structure (5,3)from Wright 4<(K); 9 from Jeffrey 457 (K); 10-11 Schlieben 11687 (P). 30* Nord. J. Bot. 5 ( 5 ) 1985 457 zyxwvutsr zyxwvutsr gated seeds (Fig. I ) . They differ in a number of important features, the most conspicuous one being the corolla size, as shown in Tab. 1. Paragenipa Baillon zyxwvutsr Bull. Mens. SOC.Linn., Paris 1: 207, 1879. -Type: Puragenipu lancifolia (Boj. ex Bak.) Tirvengadum & Robbrecht. Baillon described Paragenipa cervorurn from the Seychelles, but at the end of the protologue expressed doubt about the generic status he ascribed to Paragenipa. He thus anticipated a new delimitation of the genus Gmipa L. (Baillon 1880, p. 305 et seq. & 433) into a big gcnus. including Gardenia Ellis, Randia L., Rothmannia Thunb. etc. ..., and divided it into 22 sections, amongst them Randia, and Paragenipa. Incidentally, Baillon’s Paragenipa was never, until now, considered as congeneric with Randia lancifolia (Boj. ex Bak.) Hemsl. in the Anglo-Saxon taxonomic literature. It is worth mentioning in this context that Paragenia is listed in Index Kewensis and given as a valid generic name in Index Nominum Genericorum (Farr et al. 1979, p. 1258). Hemsley’s “Randia” was originally ascribed to the genus Pyrostria Comm. ex Juss. (P. lancifolia Boj. ex Baker) by Baker (1877, p. 149) on the basis of a flowerless “scrap” which he had inadequately described. He inadvertently published the same taxon again (Baker 1877, p. 156) as a new species of Psychotria L. (P. wrightii Baker), based on the material (Wright 45) from the Seychelles. Despite the fact that a complete diagnosis and a type specimen were cited for the latter by Baker, Hemsley (1916) in transferring Pyrostria lancifolia to Randia adopted the epithet lancifolia and quoted Psychotria wrightii in synonymy. Hemsley, in choosing the epithet “lancifolia” for his new combination “Randia lancifolia” has obviously applied the principle of “priority” in respect of Bojer’s unpublished binomial. Tirvengadum & Sastre (1979, p. 91) excluded “Randia lancifolia” from genus Randia (a genus confined to the New World) without attributing it to any tribe. Fig. 3. Pollen of Puragenipu luncifolia - A. Polar view (X ca. 1300). - B. Equatorial view (x1600). - C. Mesocolpium ( ~ 6 6 7 0 ). D . Detail of a broken wall ( X ca. 6670). - A-D from Thomasset 72 (K). with internodes much shorter than the leaves. (Fig. 2). Leaves very thickly coriaceous, ovate to oblong-lanceolate, shortly petiolate. Stipules broadly deltoid-cuspidate, early deciduous. Inflorescences 24-flowered with a short and stout stalk, axillary and opposite. Calyx broadly campanulate with 4-5 obscure teeth. Corolla infundibuliform with 4-5 ovate-oblong or almost orbicular lobes (twisted to the left in the buds). Stamens nearly entirely included in corolla with lanceolate and subsessile anthers. Pollen (Fig. 3) radially symmetrical, isopolar, 3-colporate, spherical and small (E = ca. 20 ym); exine semitectate (reticulum). Ovary 2-locular, with axile placentation; ovules many, pendulous, and z zyxwvutsr Paragenipa lancifolia (Boj. ex Bak.) Tirvengadum & Robbrecht, comb. nov. Pyrostria lancifoliu Boj. ex Bak., F1. Mauritius & Seychelles: 149, 1877. - Rundiu luncifoliu (Boj. ex Bak.) Hemsl., J. Bot. 54, suppl. 2: 17, 1916. - Type: Thomasset 90 (K). Psychotriu wrightii Baker, FI. Mauritius & Seychelles: 156, 1877. - Type: Wright 45 (K). Paragenipa cervorum Baillon, Bull. Mens. SOC.Linn., Paris 1: 207, 1879. - Genipu cervorum (Baillon) Baillon, Hist. des Plantes 7: 310, 1880. - Type: syntypes; Pervillt 31 (P), 78 (P). The former is designated lectotype and the latter paratype here; a fragment (in Herb. Baillon - P) is certainly taken from one of these collections. 0 ..,, zyxwvuts Glabrous shrub or small tree 5-6 m tall (fide Perville) with fairly stout, rigid branches swollen at the nodes and 458 :..’ , .. .? : ; i Fig. 4. Purugenipa luncifolia seed in two views with indication of embryo position ( x l l ) , and embryo ( ~ 2 3 )-. From Robertson 2275 (P). Nord. J. Bot. 5 ( 5 ) 1985 zyxwvutsrqpo zyxwvuts zyxwvutsrqp Fig. 5. Parugenipa funcifofiaseed-coat structure. - Left: outer epidermis of the testa in surface view. - Right: cross-section of the seed-coat, showing from outside to inside: outer epidermis (oe) with thickenings along radial walls, inner layers of testa (partly taking part in the mechanical strengthening of the seed-coat, partly crushed by the endosperm), and endosperm (es). Bars 100 pm. From Robertson 2275 (P). zyxwvutsr imbricately arranged. Style cylindrical, hairy near the base and deeply bifid. Fruits small, ellipsoid drupes of ca. 15 x 8 mm; epicarp thin; mesocarp fleshy and endocarp papery. Seeds (Figs 2, 4) arranged in two rows in each locule, 3.5-5 mm in diam., more or less flattened, with a short linear hilum and a fibrous seed-coat. Embryo (Fig. 4) shorter than one third of the diameter of the seed; radicle superior and pointing to one end of hilum. The elongated shape of the testa-cells and the occurrence of thickenings along their radial walls account for the fibrous nature of the seed-coat (Fig. 5). The outer epidermis of the testa forms a rigid palisade, and one or two adjacent inner layers also take part in the mechanical strengthening of the seed-coat; they have similar but smaller thickenings along the radial walls, and some additional thickenings along the inner tangential wall. All these thickenings, wherein a primary and a secondary deposit may be discerned, are smooth and elliptical in cross-section. The cells of the rest of the testa are crushed by the development of the endosperm. All these features doubles are consistent with the subtribe Hypobathrine of the Hypobathreae. The seedcoat is remarkable in being of an exotestal type with several layers of fibres (and not with a single palisade as almost exclusively in Rubiaceae), but otherwise fits well enough with other Hypobathreae. Paragenipa is related to the Madagascan Chapdieria A. Rich. and to the Mascarene Fernelia Comm. ex Lam. The delimitation of these genera is not clear and needs further investigation. Capuron (s.d., p. 54, par. 47) assembled many elements into an artificially large genus Fernelia (including Chapdieria ...). If Capuron’s concept is proved to be correct, then Parugenipa will have to be reduced to a synonym of that genus. Nargedia macrocarpa (Thw.) Bedd. FI. Sylv. S. India: t. 328 (For. Man. Bot.: CXXXIV-2,187>74 fide Stafleu & Cowan 1976, p. 162). - Hyptiunthera macrocurpu Thw., Enurn. PI. Zeyl.: 157, 1859. - Type: Ceylon, Thwaites CP 2709 (K, PDA). - Since Beddome’s publication of Nargedia, this genus remained monospecific and its taxonomic comprehension as well as that of N . macrocarpa did not improve substantially. Thwaites (op. cit.), however, pointed out that the latter species agrees in most of its characters with Hyptianthera Wight & Am., and, in the protologue, Beddome mentioned that Nargediu is perhaps only a sub-genus or section of Hyptiunthera, placing it in the tribe Gardenieae (Nargedia being an anagram of Gardenia). Hooker (1880), Schumann (1891) and Trimen (1894) conserved this position for Nargedia. In a synopsis of the Gardenieae of Ceylon, one of us (Tirvengadum 1978: 4) excluded Nargediu from the Gardenieae s.s., and later (Tirvengadum 1982: 10) pointed out that it would have to be transferred to the tribe Hypobathreae. Beddome’s illustration and protologue (Beddome 1873-74, t. 328) already clearly revealed the following important characters of the genus Nargedia: inflorescence few-flowered, condensed, axillary and opposite; corolla 4- or 5-merous, with contorted aestivation; ovary 2-locular with 2-few pendulous ovules in each locule; seeds 2-3, much compressed with deeply ruminate endosperm. We had no flowering materials among the collections available, whereby the pollen of Nargedia remains unknown, but the study of some fruiting specimens adds to our knowledge of the genus. Fruits ellipsoid to nearly globose (Fig. 6A), rather zyxwv zyxwvutsrqpon Nord. J . Bot. 5 ( 5 ) 1985 459 zyxwvutsrqpo zyxwvu Fig. 6. Nurgediu macrocurpu fruit and seed. - A . Fruit ( ~ 2 . 3 )-. B. Two views of the same seed (X3.5). - C. Seed in cross-section ( ~ 1 0 ) the ; stippling represents the presumed testa (exo- & endotesta) and white the presumed endosperm. - D. Parts of the exotesta in surface view, taken from two different spots on the seed. - E. Cross-section of a part of the seed; exotesta (et), endotesta (nt) and endosperm (es); the limit between endotesta and endosperm (not depicted in detail) is not clear because of the state of the material. - Bar 100 pm (D, E). B, D & E from Tirvengadum & Waas 691, A & C from Kostermans 24996). large (the immature ones up to 2.5 X 1.5-1.8 cm), very weakly costate and crowned by the minute persistent calyx. Fruit wall hard and sclerified; mesocarp consists of an outer part of several layers of small and tannin-rich parenchymatic tissue and of an inner part of many layers of strongly sclerified cells mixed up with some parenchyma. Seeds (only observed immature - embryo and endosperm not clearly developed) 2 or 3 in each fruit-chamber, pendulous from the dissepiment; endosperm strongly ruminate (Fig. 6C); hilum linear, apical (Fig. 6B). Seed coat brown and appearing warty under hand lens; exotesta-cells isodiametric to elongate (Fig. 6D), depending upon their location on the seed, parenchyma-like, devoid of any thickening, and very rich in tannins (Fig. 6E). All these features obviously point to the subtribe Lamprothamninae of the Hypobathreae. Polysphaeria and Galiniera (Robbrecht 1980b: Figs. 2.79 & 2.81) have the same type of rumination (deep radially arranged folds). Guliniera shares with it the less elongated to ilodiametrical exotesta-cells, a deviating character in the tribe. Nargedia is the first representative of the Lamprothamninae found outside Africa and Madagascar. I Acknowledgements - We would like to thank the administrators of the following insitutions, who have made their col- 460 lections available during visits or sent material on loan: K, L, MAU, PDA and SEY. We are also indebted to Dr H. Heine (Paris) for critically reviewing the manuscript, to Dr B. Verdcourt (Kew) for providing us with the pollen slide and S.E. Micrographs of “Randia lancifolia” and to Mrs K. Tind (Botanical Institute, Risskov) for the illustration of Paragenipa lancifolia. zyxwv zyxwv References Baillon, H. 1880. Histoire des Plantes 7: 257-503. - Librairie Hachette & Cie, Paris. Baker, J. G . 1887. Flora of Mauritius and The Seychelles. - L. Reeve & Co., London. Beddome, A. H. 187S1874. The Flora Sylvatica for South India. (Forrester’s Manual of Botany: CXXXIV-1 & 2). Gantz Brothers, Madras. Bremekamp, C. E. B. 1934. A monograph of the genus Pavettu L. - Fedd. Repert. 37: 1-208. Capuron, R. (s.d.). Rtvision des Rubiactes de Madagascar et des Comores. - Unpublished manuscript of 277 typed pages deposited at the Laboratoire de Phantrogamie, Museum National d’Histoire Naturelle. Paris. Farr, E. R., Leussink, J. A. &’ Stafleu, F. A. 1979. Index 2. - Bohn, Scheltema Nominum Genenorum Holkema, Utrecht, dr. W. Junk b.v., The Hague. Hemsley, W. B. 1916. Flora of Seychelles and Aldabra. Journ. Bot. 54. SUUUI.11: 1-24. Holmgren, P. K., Keuken, W. & Schofield, K. 1981. Index Herbariorum 1, ed. 7. - Bohn, Scheltema & Holkema, U t recht . Hooker, J. D. 1873. Ordo LXXXIV. Rubiaceae. - In: Bentham, G. & Hooker, J. D., Genera Plantarum 2: 7-151, L. Reeve & Co., London. zy Nord. J . Bot. 5 ( 5 ) 1985 zyxwvu zyxwvutsrqp zyxwvutsrqp zyxwvutsr zyxwvut - 1880. Flora British India. - L. Reeve & Co., London. Keay, R. W. J. 1958. Randia and Gardenia in West Africa. Bull. Jard. Bot. Etat Brux. 58: 15-72. Robbrecht, E . 1980a. The Hypobathreae (Rubiaceae-Ixoroideae) - Delitination and division of a new tribe. - Bull. Jard. Bot. Nat. Belg. 50: 69-77. - 1980b. Bijdragen tot de classificatie van de Ixoroideae en tot de revisie van Tricalysia s.1. (Rubiaceae). - Gent (unpubl. thesis). Schumann, K., 1891. Rubiaceae - In: Engler, A. & Prantl, K., Die Natiirlichen Pflanzenfamilien IV (4): 1-156, Leipzig. Stafleu, F. A. & Cowan, R. S. 1976. Taxonomic Literature I (Edit. 2). - Bohn, Scheltema & Holkema, Utrecht. Tirvengadum, D. D. 1978. A synopsis of the Rubiaceae-Gar- denieae of Ceylon (Sri Lanka). - Bull. Mus. natn. Hist. Nat., Paris, Bot. 35: S 3 3 . - 1982. A study of tribe Gardenieae (Rubiaceae) of South and South East Asia. Generic delimitation and revision with enumeration of species. - Ph.d. thesis, Univ. of Aarhus (unpubl.). - & Sastre, C. 1979. La signification taxonomique des modes de ramification de Randia et genres affines. - Bull. Mauritius Inst. 8 (4): 77-98. Trimen, H. 1894. A Handbook of the Flora of Ceylon 2. - Duluau & Co., London. Wight, R. & Walker-Arnott, G . A , , 1834. Prodromus Florae Peninsulae Indiae Orientalis - London. zyxwvutsrqponm Nord. J. Bot. 5 ( 5 ) 1985 461