The families of flowering plants
Including Crescentiaceae Dum.
Habit and leaf form. Trees, or shrubs, or lianas, or herbs (rarely). Self supporting, or climbing; when climbing stem twiners, or tendril climbers (via modified terminal leaflets), or root climbers; the twiners twining anticlockwise (Tecoma). Leaves opposite (mostly), or whorled, or alternate (rarely, then spiral); petiolate; non-sheathing; compound (usually), or simple; pinnate, or palmate, or bipinnate, or multiply compound. Lamina when simple dissected, or entire; when dissected pinnatifid, or palmatifid. Leaves exstipulate; without a persistent basal meristem. Domatia occurring in the family (14 genera); manifested as pits (rarely), or pockets, or hair tufts.
Leaf anatomy. Stomata present; anomocytic, or paracytic, or diacytic (Kigelia).
The mesophyll with sclerencymatous idioblasts (spicular cells), or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (Catalpa, Jacaranda, Tecomella).
Stem anatomy. Cork cambium present; initially deep-seated, or superficial. Nodes unilacunar (3 to several traces). Cortical bundles absent. Medullary bundles present (inversely orientated, e.g. in Campsis, Tecoma), or absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring, or anomalous; via concentric cambia (e.g. Campsis, Clytostoma, Tecomaria, where a second series of bundles forms internally to the primary cylinder, in the pith), or from a single cambial ring. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones (commonly), or not stratified. Included phloem absent. Xylem with libriform fibres; with vessels. Vessel end-walls simple (commonly), or simple (sometimes with numerous bars), or reticulately perforated. Vessels without vestured pits. Wood storied, or partially storied (VP, VPI), or not storied; parenchyma paratracheal.
Reproductive type, pollination. Plants hermaphrodite. Pollination entomophilous, or ornithophilous, or cheiropterophilous.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; in cymes and in racemes. The ultimate inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; usually dichasial, tending to cincinnial. Flowers somewhat irregular to very irregular. The floral irregularity involving the perianth and involving the androecium (K irregular, C sometimes more or less regular). Flowers more or less 5 merous; cyclic; tetracyclic. Hypogynous disk usually present.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous; entire, or toothed; campanulate; unequal but not bilabiate, or bilabiate; often open in bud. Corolla 5; 1 whorled; gamopetalous. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate, or valvate (rarely); usually campanulate, or funnel-shaped; bilabiate (often, the upper lip with two lobes, the lower with three), or regular (rarely).
Androecium (4–)5. Androecial members adnate (to the corolla tube); markedly unequal; free of one another; 1 whorled. Androecium nearly always including staminodes, or exclusively of fertile stamens (occasionally all five members are fertile, or the usual posterior staminode is absent). Staminodes 1 (the posterior, adaxial member), or 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 anterior-lateral pair (mostly), or 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; didynamous (mostly), or not didynamous, not tetradynamous; reduced in number relative to the adjacent perianth (usually), or isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers connivent (usually), or separate from one another; dehiscing via longitudinal slits; bisporangiate, or tetrasporangiate. Endothecium developing fibrous thickenings, or not developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Tapetum amoeboid. Pollen grains aperturate (usually), or nonaperturate; 2–12 aperturate; colpate, or colporate; 2-celled (in 13 genera).
Gynoecium 2 carpelled. The pistil 1 celled, or 2 celled, or 4 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary 1 locular, or 2 locular, or 4 locular. Locules secondarily divided by false septa, or without false septa. Gynoecium median; stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; 2 lobed; wet type; papillate; Group III type. Placentation when unilocular parietal; when 2 or 4 locular axile. Ovules in the single cavity when unilocular, 6–100 (to many); 6–50 per locule (many); ascending; orthotropous, or hemianatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral to persistent. Synergids hooked (large). Hypostase usually present (but weak). Endosperm formation cellular. Endosperm haustoria present; chalazal, or chalazal and micropylar.
Fruit non-fleshy (usually), or fleshy (rarely); dehiscent (usually), or indehiscent (rarely); a capsule (usually), or a berry (rarely). Capsules septicidal, or loculicidal. Seeds non-endospermic (with Schlegelieae excluded); winged (usually), or wingless. Cotyledons 2; flat (enlarged, foliaceous). Embryo achlorophyllous (4/4); straight.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Not cyanogenic. Alkaloids present, or absent. Iridoids detected (very commonly); Route I type (normal, doubtfully), or Route II type (normal and decarb.). Arthroquinones detected (4 genera); derived from shikimic acid. Verbascosides detected (8 genera). Cornoside detected (Eccremocarpus). Proanthocyanidins absent. Flavonols present, or absent; when present, quercetin. Ellagic acid absent (8 species, 7 genera). Arbutin absent. Ursolic acid present. Saponins/sapogenins present (rarely), or absent. Aluminium accumulation not found. Sugars transported as oligosaccharides + sucrose (predominantly), or as sugar alcohols + oligosaccharides + sucrose. C3. C3 physiology recorded directly in Catalpa, Chilopsis.
Peculiar feature. The funicles not as in Acanthaceae.
Geography, cytology. Temperate (a few), or sub-tropical and tropical (mainly). Widespread, with Catalpa common to the Old and New Worlds. N = 20 (mostly). Supposed basic chromosome number of family: 7.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgrens Superorder Lamiiflorae; Scrophulariales. Cronquists Subclass Asteridae; Scrophulariales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Lamiales.
Species 650. Genera 110; Adenocalymna, Amphilophium, Amphitecna, Anemopaegma, Argylia, Arrabidaea, Astianthus, Barnettia, Bignonia, Callichlamys, Campsidium, Campsis, Catalpa, Catophractes, Ceratophytum, Chilopsis, Clytostoma, Colea, Crescentia, Cuspidaria, Cybistax, Delostoma, Deplanchea, Digomphia, Dinklageodoxa, Distictella, Distictis, Dolichandra, Dolichandrone, Eccremocarpus, Ekmanianthe, Fernandoa, Fridericia, Gardnerodoxa, Glaziova, Godmania, Haplolophium, Haplophragma, Heterophragma, Hieris, Incarvillea, Jacaranda, Kigelia, Lamiodendron, Leucocalantha, Lundia, Macfadyena, Macranthisiphon, Manaosella, Mansoa, Markhamia, Martinella, Melloa, Memora, Millingtonia, Mussatia, Neojobertia, Neosepicaea, Newbouldia, Nyctcalos, Ophiocolea, Oroxylum, Pajanelia, Pandorea, Parabiognonia, Paragonia, Paratecoma, Parmentiera, Pauldopia, Perianthomega, Periarrabidaea, Perichlaena, Phryganocydia, Phyllarthron, Phylloctenium, Piriadacus, Pithecoctenium, Pleionotoma, Podranea, Potamoganos, Pseudocatalpa, Pyrostegia, Radermachera, Rhigozum, Rhodocolea, Roentgenia, Romeroa, Saritaea, Sparattosperma, Spathicalyx, Spathodea, Sphingiphila, Spirotecoma, Stereospermum, Stizophyllum, Tabebuia, Tanaecium, Tecoma, Tecomanthe, Tecomella, Tourrettia, Tynanthus, Urbanolophium, Xylophragma, Zeyheria.
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 provide preliminary insights from chloroplast gene sequencing.
Economic uses, etc. Important timber from Tabebuia (West Indian boxwood), Catalpa.
Illustrations. • Technical details: Kigelia (Thonner). • Technical details: Catalpa, Tecoma. • Technical details: Crescentia (Lindley). • Amphicome arguta: Bot. Reg. XXIV, 19 (1838). • Bignonia unguis-cati: as B. tweediana, Bot. Reg. xxvi, 45 (1840). • Bignonia unguis-cati: as B. picta, Bot. Reg. 45, 1842. • Colea floribunda: Bot. Reg. 19, 1841. • Eccremocarpus scaber: Bot. Reg. 939, 1825. • Pandorea jasminoides: as Tecoma, Bot. Reg. 2002, 1837. • Tecomaria capensis: Bot. Reg. 1117, 1827.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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).
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th December 2012. http://delta-intkey.com’.