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~ (Formerly) Liliaceae or Melanthiaceae, with Aletris and Lophiola assigned by Bentham & Hooker to Haemodoraceae
Habit and leaf form. Herbs. Leaves well developed. Perennial; with a basal aggregation of leaves, or without conspicuous aggregations of leaves; rhizomatous. Leaves alternate; spiral, or distichous; flat; ‘herbaceous’; sessile; sheathing. Leaf sheaths not tubular. Leaves with blades borne edgewise to the stem (Narthecium), or with blades ‘normally orientated’ (Aletris); simple. Lamina entire; linear to lanceolate; parallel-veined. Leaves eligulate.
Leaf anatomy. The leaf lamina dorsiventral, or bifacial. The mesophyll commonly containing crystals. The crystals raphides, or solitary-prismatic. Foliar vessels absent.
Axial (stem, wood) anatomy. Secondary thickening absent. The axial xylem without vessels.
Root anatomy. Root xylem with vessels; vessel end-walls scalariform.
Reproductive type, pollination. Unisexual flowers present (rarely), or absent. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the perianth (from the tepal bases).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in panicles. Inflorescences scapiflorous, or not scapiflorous; simple or compound racemes or spikes, rarely panicles. Flowers bracteate; nearly always regular; 3 merous; cyclic; usually pentacyclic. Perigone tube present (Aletris, Nietneria and Lophiola with a campanulate tube), or absent (Narthecium). Hypogynous disk absent.
Perianth of ‘tepals’; 6; free to joined; 2 whorled (3+3); isomerous; more or less petaloid; without spots, or spotted (occasionally); similar in the two whorls; white, or yellow (bright yellow in Narthecium, but usually inconspicuous, lacking patterns and spurs).
Androecium 6. Androecial members more or less free of the perianth; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; alterniperianthial. Anthers dorsifixed (hypopeltate), or basifixed; dehiscing via longitudinal slits; extrorse (usually), or introrse (occasionally). Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Microsporogenesis successive. Anther wall initially with more than one middle layer; of the ‘monocot’ type. Tapetum glandular. Pollen grains aperturate; 1 aperturate, or 2 aperturate (?); sulcate (?); 2-celled.
Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled. Gynoecium syncarpous; synovarious, or synstylovarious; superior. Ovary 3 locular; sessile. Gynoecium stylate. Styles 1, or 3; free to partially joined; apical. Stigmas 1, or 3. Placentation axile. Ovules 2–100 per locule (to ‘many’); funicled; non-arillate; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed. Endosperm formation helobial (? - by contrast with Liliales).
Fruit non-fleshy; not an aggregate; dehiscent; a capsule. Capsules septicidal, or loculicidal. Seeds endospermic. Endosperm oily. Seeds winged, or wingless (?). Embryo well differentiated. Embryo ovoid or globose. Testa without phytomelan.
Seedling. Hypocotyl internode present, or absent (?). Seedling collar not conspicuous. Cotyledon hyperphyll elongated; assimilatory; more or less circular in t.s., or dorsiventrally flattened (?). Coleoptile absent. Seedling cataphylls absent. Primary root ephemeral.
Physiology, phytochemistry. Inulin recorded (Gibbs 1974). Not cyanogenic. Alkaloids absent. Saponins/sapogenins steroidal present. Proanthocyanidins present, or absent; if present, cyanidin. Flavonols present, or absent; if present, kaempferol and quercetin. Ellagic acid absent.
Geography, cytology. Holarctic. Frigid zone, temperate, sub-tropical, and tropical. Temp. northern hemisphere, India to Japan, Malesia, N. America. Chromosomes with normal centromeres.
Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Liliiflorae; Melanthiales. APG III core angiosperms; Superorder Lilianae; non-commelinid Monocot. APG IV Order Dioscoreales.
Species about 35. Genera 6; Aletris, Lophiola, Metanarthecium, Narthecium, Nietneria.
Illustrations. • Aletris farinosa: Britton and Brown, Ill. Fl. N. U.S.A and Canada (1896). • Aletris aurea: Britton and Brown, Ill. Fl. N. U.S.A and Canada (1896). • Le Maout and Decaisne: Narthecium ossifragum. • Narthecium ossifragum: Eng. Bot. 9 (1869). • Narthecium ossifragum: Fl. von Deutschland in Abbildungen ... 1 (1906). • Narthecium ossifragum (B. Ent.).
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: 25th April 2024. delta-intkey.com’.
