Including Didymocarp(ac)eae D. Don, Ramondiaceae Godr. & Gren. ex Godr., Replicataceae Dulac
Habit and leaf form. Herbs (usually, sometimes slightly woody), or shrubs, or lianas (rarely). `Normal' plants, or plants of very peculiar form (sometimes); sometimes remarkably neotenic (with spectacular reduction of the axis - e.g. Streptocarpus, where the plant has but one leaf which represents a cotyledon, the other cotyledon having atrophied early). With a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves. Self supporting, or epiphytic (commonly), or climbing; climbers root climbers. Mesophytic. Heterophyllous (members of leaf pairs often very different in size), or not heterophyllous. Leaves opposite (usually), or alternate (rarely), or whorled (rarely); `herbaceous', or leathery; petiolate; simple; epulvinate. Lamina entire (usually), or dissected; rarely pinnatifid; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire, or serrate, or dentate. Leaves without a persistent basal meristem. Domatia recorded (Mitraria); represented by pits.
Leaf anatomy. Stomata anisocytic (often very large).
Adaxial hypodermis present, or absent. Lamina dorsiventral; with secretory cavities (accompanying the xylem, in a few genera), or without secretory cavities. Secretory cavities when present, containing oil, or containing resin. The mesophyll with sclerencymatous idioblasts, or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (Heschynanthus, Isoloma, Mitraria).
Stem anatomy. Secretory cavities present (in a few genera), or absent; when present, with oil, or with resin. Cork cambium present; initially deep-seated, or superficial. Nodes unilacunar, or tri-lacunar, or penta-lacunar. Cortical bundles present (a single one, in the stem ridge of Rhynchoglossum obliquum), or absent. Medullary bundles present (e.g. Klugia, Monophyllaea, Rhynchoglossum). Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids (Coronanthera), or without fibre tracheids; with libriform fibres, or without libriform fibres (Coronanthera); with vessels. Vessel end-walls simple. Wood partially storied (VPI, some Cyrtandra species), or not storied (?); parenchyma paratracheal (or very sparse, or absent).
Reproductive type, pollination. Hermaphrodite, or monoecious (rarely). Entomophilous, or ornithophilous, or cheiropterophilous.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in `inflorescences'. The terminal inflorescence unit cymose (usually), or racemose. Inflorescences terminal, or axillary, or epiphyllous. Flowers medium-sized to large; very irregular (usually), or somewhat irregular. The floral asymmetry involving the perianth and involving the androecium, or involving the androecium. Flowers cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk often present (when ovary superior).
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous (usually), or polysepalous (sometimes); usually valvate. Corolla 5; 1 whorled; gamopetalous; imbricate; rotate, or campanulate; bilabiate (usually), or unequal but not bilabiate, or regular (e.g. Ramonda).
Androecium 2-5. Androecial members adnate (to the corolla tube); markedly unequal (often), or all equal; free of one another (rarely), or coherent; 1 - adelphous, or 2 - adelphous; 1 - whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes 1-3 (replacing fertile members). Stamens 2, or 4(-5) (the posterior member occasionally present - e.g. Ramonda); commonly didynamous; reduced in number relative to the adjacent perianth (usually), or isomerous with the perianth; oppositisepalous. Anthers cohering, or connivent, or separate from one another (rarely); dehiscing via longitudinal slits. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or decussate. Anther wall initially with one middle layer; of the `dicot' type. Tapetum glandular. Pollen grains aperturate; (2-)3(-6) - aperturate; colporate (usually, or colporoidate), or rugate; 2-celled.
Gynoecium 2; syncarpous; synstylovarious to eu-syncarpous; superior to inferior. Ovary 1 locular (usually), or 2 locular (through meeting of the two placentae). Gynoecium median. Epigynous disk when ovary inferior, commonly present. Styles 1; attenuate from the ovary; apical. Stigmas 1-2; 1-2 - lobed; wet type, or dry type; papillate; Group II type, or Group III type. Placentation usually parietal; when bilocular, axile. Ovules in the single cavity usually (i.e. when unilocular), 15-100 (i.e. `many'); when bilocular 10-50 per locule (i.e. `many'); funicled, or sessile; non-arillate; anatropous; unitegmic; tenuinucellate. Endothelium differentiated (proximally only). Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; very ephemeral. Synergids slender, sometimes with long, tapering tips entering the micropyle and extending through its length. Endosperm formation cellular. Endosperm haustoria present; chalazal and micropylar. Embryogeny onagrad.
Fruit fleshy, or non-fleshy; dehiscent (usually), or indehiscent; a capsule (usually), or a berry (infrequently). Capsules loculicidal (usually), or valvular (sometimes), or septicidal (rarely). Seeds endospermic, or non-endospermic (Cyrtandroideae). Endosperm when present, oily. Seeds small. Cotyledons 2. Embryo achlorophyllous (1/1); straight.
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Not cyanogenic. Alkaloids absent (one species). Iridoids absent. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (4 species, 3 genera). Saponins/sapogenins absent. Aluminium accumulation not found. C3. C3 recorded in Saintpaulia. Anatomy non-C4 type (Didymocarpus).
Peculiar feature. The funicles not as in Acanthaceae.
Geography, cytology. Temperate (a few), or sub-tropical to tropical (mostly). Pantropical, a few temperate. X = 4-17(+). Supposed basic chromosome number of family 8, or 9.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren's Superorder Lamiiflorae; Scrophulariales. Cronquist's Subclass Asteridae; Scrophulariales. Takhtajan's Subclass Asteridae; Lamianae; Scrophulariales. Species 2000. Genera about 140; Achanthonema, Achimines, Aeschynanthus, Agalmyla, Allocheilos, Alloplectus, Allostigma, Ancylostemon, Anetanthus, Anna, Anodiscus, Asteranthera, Beccarinda, Bellonia, Besleria, Boea, Boeicca, Bournea, Briggsia, Briggsiopsis, Bucinellina, Calcareoboea, Capanea, Cathayanthe, Championia, Chirita, Chiritopsis, Chrysothemis, Cobananthus, Codonanthe, Codonanthopsis, Colpogyne, Columnea, Conandron, Corallodiscus, Coronanthera, Corytoplectus, Cremosperma, Cubitanthus, Cyrtandra, Dayaoshania, Deinocheilos, Depanthus, Diastema, Didissandra, Didymocarpus, Didymostigma, Dolicholoma, Drymonia, Episcia, Epithema, Eucodonia, Fieldia, Gasteranthus, Gesneria, Gloxinia, Goyazia, Gyrocheilos, Gyrogyne, Haberlea, Hemiboea, Hemiboeopsis, Heppiella, Hexatheca, Isometrum, Jancaea, Koellikeria, Kohleria, Lagarosolen, Lembocarpus, Lenbrassia, Leptobaea, Lietzia, Linnaeopsis, Loxocarpus, Loxonia, Loxostigma, Lysionotus, Metabriggsia, Metapetrocosmea, Micraeschynanthus, Mitraria, Monophyllaea, Monopyle, Moussonia, Napeanthus, Nautilocalyx, Negria, Nematanthus, Neomortonia, Niphaea, Nodonema, Oerstedina, Opithandra, Orchadocarpa, Oreocharis, Ornithoboea, Oxychlamys, Paliavana, Paraboea, Paradrymonia, Parakohleria, Pearcea, Petrocodon, Petrocosmea, Pheidonocarpa, Phinaea, Phyllobaea, Platyadenia, Primulina, Pseudochirita, Ramonda, Reldia, Resia, Rhabdothamnopsis, Rhabdothamnus, Rhoogeton, Rhynchoglossum, Rhynchotechum, Rhytidophyllum, Rufodorsia, Saintpaulia, Sarmienta, Schistolobos, Schizoboea, Sepikea, Sinningia, Smithiantha, Solenophora, Stauranthera, Streptocarpus, Tengia, Tetraphyllum, Thamnocharis, Titanotrichum, Trachystigma, Tremacron, Trisepalum, Tylopsacas, Vanhouttea, Whytockia.
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