The families of flowering plants
The families of flowering plants | |
~ Luzuriagaceae, Philesiaceae, Smilacaceae
Habit and leaf form. Unarmed, glabrous shrubs, or lianas (from short rhizomes, with the habit of Asparagus asparagoides). Switch-plants (‘with alternating, sessile phyllodes’), or ‘normal’ plants (see comments below); if the ‘leaves’ are really phyllodes, phyllodineous. Leaves well developed, or much reduced (?). Perennial; with neither basal nor terminal aggregations of leaves; rhizomatous (?). Self supporting, or climbing; the climbers stem twiners; stems twisting dextrorsely. Xerophytic. Leaves (if they are not phyllodes!) alternate; distichous; shortly petiolate; non-sheathing (‘without a sheathing base’); simple. Lamina parallel-veined; cross-venulate. Lamina margins entire.
Leaf anatomy. The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides.
Stem anatomy. Young stems cylindrical. Secondary thickening anomalous (in the rhizome); from a single cambial ring.
Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Plants (crypto) dioecious (the female flowers with smaller, sterile stamens, the males with a sterile nectariferous ovary). Female flowers with staminodes. Gynoecium of male flowers pistillodial (nectariferous). Floral nectaries present. Nectar secretion from the gynoecium (with septal nectaries).
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’ (articulated on their pedicels); terminal; when aggregated, in cymes, or in racemes (a bostryx). The ultimate inflorescence unit cymose. Inflorescences axillary. Flowers small; regular; 3 merous. Floral receptacle developing a gynophore. Perigone tube present (this campanulate, about two thirds the lenght of the perianth).
Perianth of ‘tepals’; 6; joined; 2 whorled; isomerous; petaloid; green, or white; persistent (marcescent, not becoming twisted).
Androecium 6. Androecial members adnate (‘to the middle of the perigone tube’); all equal; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; alterniperianthial. Anthers dorsifixed to basifixed (?); dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Microsporogenesis successive. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; sulcate; 2-celled (?).
Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 3 locular; stipitate (‘basally contracted into a thick gynophore’). Gynoecium stylate. Styles 1; free; attenuate from the ovary; apical. Stigmas 1; 3 lobed. Placentation axile. Ovules 2–3 per locule, or 3–7 per locule (?); biseriate (?); anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type.
Fruit fleshy; indehiscent; a berry; few to many. Seeds copiously endospermic. Endosperm oily. Seeds without starch. Cotyledons 1. Embryo straight. Testa encrusted with phytomelan; black (thick).
Geography, cytology. Paleotropical and Cape. South Africa.
Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Liliiflorae; Asparagales. APG 3 core angiosperms; Superorder Lilianae; non-commelinid Monocot; Order Asparagales (as a synonym of Asparagaceae?).
Species 1. Genera 1; Behnia only.
General remarks. See Conran et al, (1997), Reveal (1998). Even the more detailed description of the former is fairly inadequate. It makes no reference to phyllodes, but perhaps significantly records the ‘leaves’ as non-sheathing.
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’.