The families of flowering plants
Habit and leaf form. Herbs (usually repent or prostrate, mostly glabrous), or shrubs (some subshrubs). Plants succulent, or non-succulent; autotrophic (mostly), or carnivorous (? - perhaps in the Australian, glandular-hairy Vandellia, cf. Byblidaceae, but genuine carnivory has yet to be demonstrated). Annual, or biennial, or perennial (mostly annual); rhizomatous. Helophytic, or mesophytic, or xerophytic (including some resurrection plants, e.g. Craterostigma). Leaves opposite (the petioles sometimes basally fused); petiolate to sessile (sometimes with winged petioles); simple (usually), or compound (sometimes pinnate in Scolophyllum); epulvinate. Lamina dissected (then dentate or crenate), or entire; pinnately veined, or palmately veined. Leaves exstipulate. Lamina margins entire, or crenate, or serrate. Leaf development not graminaceous.
General anatomy. Plants without laticifers.
Leaf anatomy. Hairs present; eglandular, or glandular; unicellular, or multicellular. Unicellular hairs branched, or simple.
Axial (stem, wood) anatomy. Young stems often tetragonal. Secretory cavities absent. Primary vascular tissues in a cylinder, without separate bundles.
The vessels in radial rows.
Reproductive type, pollination. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the disk. Pollination entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when solitary, axillary; when not solitary, in racemes, or in heads. The ultimate inflorescence units racemose. Flowers ebracteate; very irregular; zygomorphic; resupinate (e.g., sometimes in Lindernia), or not resupinate. The floral irregularity involving the perianth. Flowers cyclic; tetracyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 8–10; 2 whorled; isomerous to anisomerous. Calyx (4–)5; 1 whorled; gamosepalous (fused basally); unequal but not bilabiate, or regular; persistent. Corolla 4–5 (with abaxial glandular hairs, the two posterior lobes united or almost so); 1 whorled; appendiculate (Lindernia with flaps covering the anthers); gamopetalous. Corolla lobes markedly shorter than the tube. Corolla two-lipped to funnel-shaped; markedly bilabiate (the posterior one sometimes much shorter), or regular; white, or purple, or blue; plain, or with contrasting markings (usually).
Androecium (2–)4(–5) (sometimes the lower pair reduced or missing). Androecial members adnate (to the corolla tube); markedly unequal; free of one another, or coherent (the posterior pair often connivent); 1 whorled. Androecium exclusively of fertile stamens, or including staminodes (the two anterior members reduced to staminodes or lacking in some Lindernia spp.). Staminodes when present, 2; in the same series as the fertile stamens; representing the anterior-lateral pair. Fertile stamens representing the posterior-lateral pair, or the posterior-lateral pair and the anterior-lateral pair. Stamens 2, or 4; reduced in number relative to the adjacent perianth, or isomerous with the perianth; oppositisepalous; alternating with the corolla members. Filaments appendiculate (spurred), or not appendiculate. Anthers separate from one another, or connivent; dorsifixed; introrse.
Gynoecium 2 carpelled (?). Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synstylovarious (the long style with a two-lobed, lamellate stigma); superior. Ovary 2 locular. Gynoecium median; long stylate. Styles 1; apical. Stigmas 1; 2 lobed; bilobed; wet type; papillate. Placentation basal to axile. Ovules 10–50 per locule ('many').
Fruit non-fleshy; dehiscent; a capsule. Capsules poricidal (occasionally), or septicidal. Seeds endospermic. Endosperm ruminate. Cotyledons 2.
Physiology, phytochemistry. C3 (?).
Geography, cytology. Holarctic, Paleotropical, Neotropical, and Cape. Temperate, sub-tropical, and tropical. More or less worldwide in warmer regions, especially Orient, neotropics and southern United States.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgrens Superorder Lamiiflorae; Scrophulariales. Cronquists Subclass Asteridae; Scrophulariales. APG III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Lamiales.
Species almost 200. Genera 16; Amphiolanthus, Artanemia, Bampsia, Craterostigma, Crepidorhopalon, Hartliella, Hemiarrhena, Ilysanthes, Lagaspia, Lindernia, Picria, Pierranthus, Schizotorenia, Scolophyllum, Torenia, Vandellia.
General remarks. This very inadequate description (cf. Christenhusz et al. (2017) represents one of numerous dubiously worthwhile APG segregates from Scrophulariaceae.
Illustrations. • Hemiarrhena plantagina: Hook. Ic. Pl. 11 (1867–71). • Lindernia dilatata (cf. L. dubia): Baringer, Flora Costaricensis 41 (2000).
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: 5th March 2018. delta-intkey.com/angio’.