Family Verbenaceae
Verbenaceae Jaume St-Hil.Including Cyclocheilaceae W. Marais, Durantaceae J.G. Agardh, Nesogenaceae W. Marais, Petreaceae J.G. Agardh, Pyrenaceae Vent., Vitices (Viticaceae) Juss.Excluding Dicrastylidaceae, Phrymataceae, Stilbaceae, Symphoremataceae Habit and leaf form. Trees, shrubs, and herbs, or lianas (many); non-laticiferous and without coloured juice; bearing essential oils. ‘Normal’ plants and switch-plants; sometimes with the principal photosynthesizing function transferred to stems. Leaves well developed, or much reduced (occasionally). Plants non-succulent. Self supporting, or climbing; the climbers stem twiners, or scrambling; Clerodendrum twining clockwise. Mesophytic and xerophytic. Leaves opposite (usually), or whorled, or alternate (rarely); petiolate to sessile; foetid, or without marked odour, or aromatic; simple, or compound; epulvinate; when compound, ternate to pinnate (e.g.Vitex), or palmate. Lamina dissected, or entire; when dissected, pinnatifid; pinnately veined; cross-venulate. Leaves exstipulate; without a persistent basal meristem. Domatia occurring in the family (4 genera); manifested as pits, or pockets, or hair tufts. Leaf anatomy. The mesophyll with sclerencymatous idioblasts, or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (6 genera). Stem anatomy. Young stems tetragonal (often), or cylindrical, or oval in section. Cork cambium present; initially deep-seated (rarely), or superficial. Nodes unilacunar (1–several traces). Internal phloem absent. Secondary thickening developing from a conventional cambial ring. The secondary phloem not stratified. ‘Included’ phloem absent. Xylem with libriform fibres; with vessels. Vessel end-walls simple. Vessels without vestured pits. Reproductive type, pollination. Plants hermaphrodite (usually). Pollination entomophilous. Inflorescence, floral, fruit and seed morphology. Flowers usually aggregated in ‘inflorescences’; in cymes, in racemes, in spikes, in heads, and in verticils. The ultimate inflorescence unit cymose, or racemose. Inflorescences terminal, or axillary; with involucral bracts (often, these commonly coloured), or without involucral bracts; pseudanthial (sometimes), or not pseudanthial. Flowers bracteate; small to medium-sized; very irregular (usually), or regular to somewhat irregular. The floral irregularity involving the perianth and involving the androecium. Flowers (4–)5(–8) merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent; when present, annular. Perianth with distinct calyx and corolla; (7–)10(–16); 2 whorled; isomerous, or anisomerous. Calyx (2–)5(–8); 1 whorled; gamosepalous; entire, or lobulate, or blunt-lobed, or toothed. Calyx lobes markedly shorter than the tube to markedly longer than the tube. Calyx unequal but not bilabiate, or regular, or bilabiate (e.g. Phyla); persistent; when K5, with the median member posterior. Corolla (4–)5(–8); 1 whorled; gamopetalous. Corolla lobes markedly shorter than the tube, or about the same length as the tube. Corolla imbricate; tubular (usually), or campanulate (rarely); unequal but not bilabiate, or bilabiate, or regular (rarely). Androecium (2–)4(–5). Androecial members adnate (to the corolla tube); markedly unequal (usually), or all equal (rarely); free of one another; 1 whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 1–3; in the same series as the fertile stamens; representing the posterior median member, or the posterior median member and the posterior-lateral pair; non-petaloid. Fertile stamens representing the posterior-lateral pair and the anterior-lateral pair (usually), or the anterior-lateral pair, or the posterior median member, the posterior-lateral pair, and the anterior-lateral pair. Stamens (2–)4(–5) (the posterior member usually, and sometimes the three upper members, reduced or missing); inserted near the base of the corolla tube, or midway down the corolla tube, or in the throat of the corolla tube; usually didynamous; reduced in number relative to the adjacent perianth (usually), or isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers connivent (in pairs), or separate from one another; dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. 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; of the ‘dicot’ type, or of the ‘monocot’ type. Tapetum glandular. Pollen grains aperturate; (2–)3(–5) aperturate, or 6 aperturate; colpate, or colporate, or rugate; 2-celled (in 9 genera), or 3-celled (in 3 genera). Gynoecium 2 carpelled (usually), or 4 carpelled, or 5 carpelled. Carpels reduced in number relative to the perianth (usually), or isomerous with the perianth. The pistil 2–10 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 2 locular, or 4–5 locular (but the original locules (usually two) early becoming divided by a ‘false septum’ in each — cf. Labiatae). Locules secondarily divided by ‘false septa’ (usually), or without ‘false septa’. Gynoecium usually median; stylate. Styles 1; attenuate from the ovary, or from a depression at the top of the ovary (but the ovary apex no more than slightly lobed); apical, or lateral. Stigmas 1; 1 lobed, or 2 lobed; wet type; papillate; Group III type and Group IV type. Placentation basal to axile, or axile. Ovules 2 per locule (i.e. in the true locules, one each in the locelli); pendulous, or horizontal, or ascending (but always with the micropyle directed downwards); non-arillate; orthotropous, or hemianatropous, or anatropous; unitegmic; tenuinucellate. Endothelium not differentiated. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; ephemeral (usually), or persistent. Synergids usually hooked (and beaked). Endosperm formation cellular. Endosperm haustoria present; chalazal and micropylar (the latter usually the less well developed). Embryogeny onagrad. Fruit fleshy (usually), or non-fleshy; dehiscent (rarely), or indehiscent (mostly), or a schizocarp. Mericarps when schizocarpic, 4 (usually), or 8–10, or 2 (?); comprising nutlets, or comprising drupelets. Fruit when non-schizocarpic a drupe (usually), or a capsule. Capsules valvular (with 2–4 valves). The drupes with separable pyrenes, or with one stone. Seeds non-endospermic (except Nesogenes). Cotyledons 2 (expanded, flat). Embryo achlorophyllous (5/5); straight. Seedling. Germination phanerocotylar, or cryptocotylar. Physiology, biochemistry. Cyanogenic, or not cyanogenic. Alkaloids present, or absent. Iridoids detected; ‘Route I’ type (normal, in some Verbena), or ‘Route II’ type (mostly, normal and decarb.). Arthroquinones detected (Tectona); derived from shikimic acid. Verbascosides detected (5 genera, excluding Phyla). Cornoside detected (Phyla). Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (5 genera, 6 species). Ursolic acid present. Saponins/sapogenins present, or absent. Aluminium accumulation not found. Sugars transported as oligosaccharides + sucrose (the 8 genera screened all particularly rich in oligosaccharides). C3. C3 physiology recorded directly in Verbena. Anatomy non-C4 type (Cleodendron, Lantana, Premna, Stachytarpheta, Verbena, Vitex). Geography, cytology. Temperate, or sub-tropical to tropical (mainly). Very widespreadtemperate and tropical, but absent from central and Northern Eurasia. X = 5–12. Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Lamiiflorae; Lamiales. Cronquist’s Subclass Asteridae; Lamiales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Lamiales. Species about 3000. Genera about 90; Acantholippia, Adelosa, Aegiphila, Aloysia, Amasonia, Archboldia, Asepalum, Baillonia, Bouchea, Burroughsia, Callicarpa, Caryopteris, Casselia, Chascanum, Citharexylum, Clerodendrum, Coelocarpum, Coelocarpum, Cornutea, Cyclocheilon, Dimetra, Diostea, Dipyrena, Duranta, Faradaya, Garrettia, Geunsia, Glandularia, Glossocarya, Gmelina, Hierobotana, Holmskioldia, Hosea, Huxleya, Hymenopyramis, Junellia, Karomia, Lampaya, Lantana, Lippia, Monochilus, Nashia, Neorapinia, Neosparton, Nesogenes, Oncinocalyx, Oxera, Paravitex, Parodianthus, Peronema, Petitia, Petraeovitex, Petraea, Phyla, Pitraea, Premna, Priva, Pseudocarpidium, Recordia, Rehdera, Rhaphithamnus, Schnabelia (or Labiatae), Stachytarpheta, Stylodon, Surfacea, Tamonea, Tectona, Teijsmanniodendron, Tetraclea (or Labiatae), Teucridium, Tsoongia, Ubochea, Urbania, Verbena, Verbenoxylum, Vitex, Viticipremna, Xeroaloysia, Xolocotzia. For comment on the taxonomically unsatisfactory circumscription of Verbenaceae employed here, see remarks under Labiatae. Economic uses, etc. Timber from Tectona grandis (teak); some notable ornamentals, e.g. Clerodendrum, Callicarpa, Vitex, Lantana, Verbena; noxious, photosensitizing weeds (Lantana). Illustrations. |
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