The Families of Angiosperms

L. Watson and M.J. Dallwitz

Scrophulariaceae Juss.

Including Antirrhineae (Antirrhinaceae) DC. & Duby, Aragoaceae D. Don, Cheloneae (Chelonaceae) Augier ex Martinov, Calceolariaceae Olmstead, Diditalaceae Augier ex Martinov, Hebenstreitiaceae Horan., Limoselleae (Limosellaceae) J.G. Agardh, Linderniaceae Borsch, K. Müll.bis & Fisch, Mazaceae, Melampyraceae Lindl., Oftiaceae, Paulowniaceae Nakai, Pedicularis (Pedicularidaceae) Juss., Personaceae Dulac, Phrymaceae p.p., Rhinanthoideae (Rhinanthaceae) Vent., Schlegeliaceae Reveal, Selaginaceae Choisy, Sibthorpiaceae D. Don, Verbascaceae Nees, Veronicaceae Rafin.; excluding Cyclocheilaceae, Ellisiophyllaceae, Orobanchaceae.

Habit and leaf form. Shrubs and herbs (mostly), or trees, or lianas; non-laticiferous, without coloured juice. Leaves well developed (usually), or much reduced (e.g., in the parasitic Harveya, Hyobanche), or absent (?). Plants succulent (somewhat, in Bacopa, Lindernia), or non-succulent; autotrophic, or parasitic (commonly, especially in the Rhinantheae), or autotrophic; green and photosynthesizing; parasitic when mycoheterotrophic, on roots of the host. Annual, or biennial, or perennial; with a basal aggregation of leaves, or without conspicuous aggregations of leaves, or with terminal aggregations of leaves (e.g. sometimes in Peplidium). Climbing (sometimes), or self supporting (mainly); the climbers stem twiners, or petiole twiners. Hydrophytic (e.g. ‘Ambulia’, = Limnophila), or helophytic, or mesophytic, or xerophytic (e.g. the ericoid Selagineae); when hydrophytic, rooted. Leaves of aquatics submerged, or emergent, or floating. Conspicuously heterophyllous (e.g. Hebe, Hydrotriche), or not conspicuously heterophyllous. Leaves alternate, or opposite, or whorled; when alternate spiral, or four-ranked; ‘herbaceous’, or leathery, or fleshy (rarely), or membranous (rarely); petiolate to sessile, or perfoliate (occasionally); connate (occasionally?), or not connate (usually); sheathing, or non-sheathing; simple (usually), or simple to compound (occasionally, when deeply pinnatifid as exemplified in Pedicularis); epulvinate. Lamina dissected, or entire; if dissected pinnatifid, or palmatifid, or much-divided (e.g. submerged leaves in Hydrotriche, Limnophila); pinnately veined, or palmately veined. Leaves exstipulate. Lamina margins entire, or crenate, or serrate, or dentate. Leaf development not ‘graminaceous’.

Leaf anatomy. The leaf lamina variously dorsiventral to bifacial. Hydathodes present (occasionally), or absent. Stomata present; mainly confined to one surface, or on both surfaces; anomocytic, or anisocytic. Hairs present (often numerous, the family exhibiting diverse forms); eglandular and glandular; unicellular and multicellular. Complex hairs present, or absent; commonly glandular and peltate. Adaxial hypodermis present (rarely, e.g. in Veronica spp.), or absent. Cystoliths present (occasionally), or absent. The mesophyll containing crystals (but rather infrequent), or without crystals. The crystals when present, nearly always small and solitary-prismatic (the large prismatic forms and druses recorded in Paulownia seemingly being unknown elsewhere in the family). Minor leaf veins with phloem transfer cells (9 genera, e.g. Antirrhinum, Rhinanthus), or without phloem transfer cells (16 genera, e.g. Pedicularis, Scrophularia, Verbascum).

Axial (stem, wood) anatomy. Pith with diaphragms, or without diaphragms. Cork cambium present, or absent (may herbaceous forms lacking cork); when present, initially deep-seated, or initially superficial. Nodes unilacunar. Primary vascular tissues usually in a cylinder, without separate bundles; collateral. Internal phloem absent (i.e., unlike Solanaceae). Secondary thickening absent (sometimes?), or developing from a conventional cambial ring (usually). Primary medullary rays commonly absent in herbaceous genera.

The wood ring porous to diffuse porous. The vessels small to large (but typically small and sometimes extremely so, rarely large). The vessel end-walls simple. The vessels without vestured pits; with spiral thickening, or without spiral thickening. The axial xylem with fibre tracheids (rarely), or without fibre tracheids; with libriform fibres (usually), or without libriform fibres; including septate fibres (rarely), or without septate fibres. The fibres without spiral thickening. The parenchyma if present, apotracheal, or paratracheal (usually very sparse or absent); wood partially storied (VPI, Penstemon), or not storied. Tyloses neary always absent, or present (but recorded only in Paulownia).

Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite. Pollination entomophilous, or ornithophilous (bees and hummingbirds); mechanism conspicuously specialized (with loose-pollen mechanisms), or unspecialized.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes, or in racemes, or in spikes, or in heads, or in panicles. The ultimate inflorescence units cymose, or racemose. Inflorescences terminal, or axillary; mainly racemes, spikes and thyrses, terminal peloric flowers common. Flowers bracteate, or ebracteate; bracteolate, or ebracteolate; minute, or small to medium-sized (mostly), or large; very irregular (usually — apart from peloric terminal flowers), or somewhat irregular (e.g. Verbascum, Bacopa, Elacholoma); resupinate (e.g., in Lindernia hypandra), or not resupinate (usually). The floral irregularity involving the perianth and involving the androecium, or involving the androecium. Flowers neither papilionaceous nor pseudo-papilionaceous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present.

Perianth with distinct calyx and corolla; (6–)8–10(–13); 2 whorled; isomerous, or anisomerous. Calyx sometimes difficult to interpret, with the posterior member missing, or the anterior pair united, etc., 3, or 4, or 5; 1 whorled; gamosepalous (usually), or polysepalous (Dischisma, Bacopa); blunt-lobed, or toothed, or entire (sometimes, in Centranthera); unequal but not bilabiate, or bilabiate, or regular; neither appendaged nor spurred; persistent; imbricate, or valvate; when K5, with the median member posterior. Corolla 4 (the posterior pair united), or 5(–8), or 3 (sometimes, in Glossostigma); 1 whorled; appendiculate (e.g. with flaps covering the anthers, in Lindernia), or not appendiculate; gamopetalous (in bud having the two posterior teeth or the upper lip covering the laterals, or in Rhinanthoideae these covered by one or both of the laterals); imbricate, or valvate; more or less bilabiate (usually), or unequal but not bilabiate (e.g. Dischisma, Hebenstretia, where the upper lip is four-lobed and the lower lip is more or less suppressed), or regular (more or less, in Verbascum, etc., as well as in the peloric terminal flowers exemplified in Linaria and Digitalis); spurred (sometimes), or not spurred; not fleshy; persistent, or deciduous.

Androecium (4–)5 (posterior member sometimes missing), or 2(–3) (sometimes the lower pair reduced or missing). Androecial members adnate (to the corolla); usually markedly unequal; free of one another, or coherent (via the anthers, in Centranthera, Cymbalaria, Elacholoma etc.); 1 whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present 1 (the posterior member), or 2–3; in the same series as the fertile stamens; representing the posterior median member, or the posterior median member and the posterior-lateral pair. Fertile stamens representing the posterior-lateral pair and the anterior-lateral pair (usually), or the posterior-lateral pair (?), or the anterior-lateral pair, or the posterior median member, the posterior-lateral pair, and the anterior-lateral pair. Stamens (2–)4(–5); inserted near the base of the corolla tube, or midway down the corolla tube, or in the throat of the corolla tube; didynamous (usually), or not didynamous, not tetradynamous; reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous; alternating with the corolla members. Filaments appendiculate (sometimes spurred, in Lindernia), or not appendiculate. Anthers cohering, or connivent (in pairs), or separate from one another; morphologically sometimes difficult to interpret morphologically being variously more or less dorsifixed, or dorsifixed to basifixed (the thecae conventionally joined along their length by the connective, or more or less separate with the connective reduced as in Angelonia, occasionally - cf. Lindenbergia - the thecae completely and widely separated); not becoming inverted during development; dehiscing via pores (Bartsia, some Euphrasia spp.), or dehiscing via longitudinal slits; introrse; unilocular (Selagineae, according to Hutchinson), or bilocular (usually); bisporangiate (e.g. Jamesbrittenia), or tetrasporangiate (usually). Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer, or initially with more than one middle layer (1 or 2); of the ‘dicot’ type. Tapetum glandular. Pollen grains aperturate; 2–7 aperturate; colporate (commonly, or colporoidate), or colpate; 2-celled (in 19 genera).

Gynoecium 2(–3) carpelled. The pistil 2(–3) celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 2(–3) locular. Locules without ‘false septa’. Gynoecium median; stylate. Styles 1; without an indusium; attenuate from the ovary, or from a depression at the top of the ovary; apical. Stigmas 1, or 2; when single, usually 1–2 lobed; wet type, or dry type; papillate; Group II type and Group III type. Placentation axile, or apical (Selagineae). Ovules 1 per locule (Selagineae), or 2–50 per locule (i.e. to ‘many’); pendulous to ascending, or pendulous (Selagineae); non-arillate; anatropous, or campylotropous, or hemianatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type, or Allium-type, or Drusa-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 2 (Mimulus, one being binucleate), or 3; not proliferating; ephemeral to persistent. Synergids pear-shaped, or hooked. Hypostase present, or absent. Endosperm formation cellular. Endosperm haustoria present (usually), or absent; when developed, chalazal and micropylar (usually), or chalazal, or micropylar. Embryogeny onagrad, or solanad.

Fruit non-fleshy (usually), or fleshy (rarely); dehiscent (usually), or indehiscent (rarely), or a schizocarp (Selagineae, Lagotis). Mericarps when schizocarpic, 2, or 1 (one often sterile or obsolete in Selagineae). Fruit when non-schizocarpic, i.e. usually, a capsule (usually), or a berry, or capsular-indehiscent (e.g. sometimes in Kickxia). Capsules septicidal (usually), or loculicidal, or poricidal (occasionally), or circumscissile, or splitting irregularly. Seeds endospermic. Endosperm oily. Seeds minute, or small; not conspicuously hairy; winged, or wingless (often angled); without amyloid. Embryo usually well differentiated. Cotyledons 2. Embryo chlorophyllous (3/3), or achlorophyllous (12/26); straight to curved.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. C₃, or C₄. C₃ physiology recorded directly in Agalinis, Antirrhinum, Castilleja, Gratiola, Linaria, Lindenbergia, Mimulus, Orthocarpus, Pentstemon. C₄ physiology recorded directly in Anticharis. Anatomy non-C₄ type (Agalinis, Castilleja, Gratiola, Limnophila, Linaria, Orthocarpus, Penstemon, Scrophularia). Sugars transported as oligosaccharides + sucrose (in Paulownia). Cyanogenic (rarely), or not cyanogenic. Cynogenic constituents phenylalanine-derived. Alkaloids present, or absent (mostly). Anthraquinones detected (3 genera); derived from shikimic acid. Verbascosides detected (14 genera). Cornoside detected (4 genera). Iridoids detected (commonly, including in Selagineae); ‘Route I’ type (doubtfully, normal), or ‘Route II’ type (normal and decarb.). Saponins/sapogenins present, or absent. Proanthocyanidins absent. Flavonols to all intents and purposes, absent. Ellagic acid absent (13 species, 9 genera). Aluminium accumulation not found. Sieve-tube plastids S-type.

Special distinguishing feature. The funicles not as in Acanthaceae.

Geography, cytology. Frigid zone to tropical. Cosmopolitan. X = 6 (or more).

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Scrophulariales. Cronquist’s Subclass Asteridae; Scrophulariales. APG III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Lamiales.

Species 3000. Genera about 280; Acanthorrhinum, Achetaria, Adenosma, Agathelpis, Albraunia, Alectra, Allocalyx, Alonsoa, Amalophyllon, Amphianthus, Amphiolanthus, Anarrhinum, Anastrabe, Angelonia, Antherothamnus, Anticharis, Antirrhinum, Aptosimum, Aragoa, Artanema, Asarina, Auriolaria, Bacopa, Bampsia, Basistemon, Baumia, Benjaminia, Besseya, Bowkeria, Brachystigma, Brandisia, Brookea, Bryodes, Bungea, Buttonia, Bythophyton, Calceolaria, Calorhabdos, Camptoloma, Campylanthus, Capraria, Celsia (= Verbascum), Centranthera, Centrantheropsis, Chaenorhinum, Charadrophila, Cheilophyllum, Chelone, Chenopodiopsis, Chionohebe, Chionophila, Clevelandia, Cochlidiosperma, Collinsia, Colpias, Conobea, Craterostigma, Crepidorhopalon, Cromidon, Cycniopsis, Cycnium, Cymbalaria, Cyrtandromoea, Dasistoma, Deinostema, Dermatobotrys, Detzneria, Diascia, Diclis, Digitalis, Dintera, Diplacus, Dischisma, Dizygostemon, Dodartia, Dopatrium, Elacholoma, Encopella, Epixiphium, Eremogeton (or Myoporaceae), Erinus, Escobedia, Esterhazya, Faxonanthus (or Myoporaceae), Fonkia, Freylinia, Galvezia, Gambelia, Geochorda, Gerardiina, Ghikaea, Glekia, Globulariopsis, Glossostigma, Glumicalyx, Gosela, Graderia, Gratiola, Halleria, Harveya, Hebe, Hebenstretia, Hedbergia, Hemianthus, Hemiarrhena, Hemichaena, Hemimeris, Hemiphragma, Hiernia, Holmgrenanthe, Holzneria, Howelliella, Hydranthelium, Hydrotriche, Hygea (or Gesneriaceae), Hyobanche, Ildefonsia, Isoplexis, Ixianthes, Jamesbrittenia, Jerdonia (or Gesneriaceae), Jovellana, Kashmiria, Keckiella, Kickxia, Lafuentea, Lagotis, Lamourouxia, Lancea, Legazpia, Leptorhabdos, Leucocarpus, Leucophyllum (or Myoporaceae), Leucosalpa, Leucospora, Limnophila, Limosella, Linaria, Lindenbergia, Lindernia, Lophospermum, Lyperia, Mabrya, Macranthera, Maeviella, Magdalenaea, Manulea, Manuleopsis, Maurandella, Maurandya, Mazus, Mecardonia, Melanospermum, Melasma, Melosperma, Micranthemum, Micrargeria, Micrargeriella, Microcarpaea, Microdon, Mimetanthe, Mimulicalyx, Mimulus, Misopates, Mohavea, Monochasma, Monopera, Monttea, Moscheovia, Nanorrhinum, Nemation, Nathaliella, Nemesia, Neogaerrhinum, Neopicrorhiza, Nothochelone, Nothochilus, Nuttallanthus, Odicardis, Oftia (or Myoporaceae), Omphalotrix, Ophiocephalus, Oreosolen, Otacanthus, Ourisia, Paederota, Paederotella, Parahebe, Parastriga, Paulownia, Peliostomum, Pennelianthus, Penstemon, Peplidium, Phygelius, Phyllopodium, Physocalyx, Picria, Picrorhiza, Pierranthus, Polycarena, Porodittia, Psammetes, Pseudobartsia, Pseudolysimachion, Pseudomelasma, Pseudorontiuim, Pseudosopubia, Pseudostriga, Pterygiella, Radamaea, Rehmannia, Rhamphicarpa, Raphispermum, Rhodochiton, Rhynchocorys, Russelia, Sairocarpus, Schistophragma, Achizosepala, Schizotorenia, Schlegelia, Schwalbea, Schweinfurthia, Scolophyllum, Scoparia, Scrofella, Scrophularia, Selago, Seymeria, Seymeriopsis, Shiuyinghua, Sibthorpia, Silviella, Siphonostegia, Sopubia, Spirostegia, Stemodia, Stemodiopsis, Strigina, Strobilopsis, Sutera, Synthyris, Teedia, Tetranema, Tetraselago, Tetraspidium, Tetraulacium, Thunbergianus, Tonella, Torenia, Tozzia, Triaenophora, Trieena, Trungboa, Tuerckheimocharis, Uroskinnera, Vellosiella, Verbascum, Veronica, Veronicastrum, Walafrida, Wightia, Wulfenia, Wulfeniopsis, Xizangia, Xilocalyx, Zaluzianska. Rhinanthoideae-Rhinantheae and Gerardiëae should probably be transferred to Orobanchaceae: Agalinis, Bartsia, Castilleja, Cordylanthus, Euphrasia, Gerardia, Melampyrum, Odontites, Orthocarpus, Parentucellia, Pedicularis, Ptheirospermum, Rhinanthus, Striga, Tozzia, Triphysaria.

General remarks. For discussion of classificatory problems posed by Scrophulariaceae, impinging on Bignoniaceae, Buddlejaceae, Callitrichaceae, Plantaginaceae, Hippuridaceae, Lentibulariaceae, and Hydrostachydaceae, and such problem genera as Paulownia and Schlegelia, see Olmstead and Reeves (1995), who provided preliminary insights from chloroplast gene sequencing. The implication is that the traditional family Scrophulariaceae comprises two distinct clades, involving numerous other small families; but no attempt is made here to incorporate the radical APG re-organization of generic assignments, involving (for example) transfer to the little family Plantaginaceae sensu stricto (q.v.) of about 90 genera and 1,500 species of traditional Scrophulariaceae, the practical worth of which in terms of character correlations remains to be demonstrated. Meanwhile, a strong argument can be made for referring Rhinanthoideae to the Orobanchaceae.

Economic uses, etc. Many are poisonous, a few are (e.g. Digitalis) or have been officinal, Halleria has edible fruit (umbinza). Many constitute important ornamentals, and Limnophila (‘Ambulia’) is used in aquaria.

Quotations.

With Antique Mullein’s flannel leaves
(John Clare, quoted by Ann Pratt, ‘Wild Flowers’ (1857) - Verbascum)

Snap dragons gaping like to sleeping clowns
(John Clare 1827, ‘The Shepherd’s Calendar’, June)

. . . . then purged with Euphrasy and Rue
The visual nerve, for he had much to see
(Milton, quoted by Ann Pratt, ‘Wild Flowers’ (1857) - Euphrasia = ‘Eyebright’)

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th April 2024. delta-intkey.com’.

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