Hemerocallidaceae R. Br.
~ Liliaceae - Hemerocallidae
Habit and leaf form. Lilylike, glabrous herbs. Perennial; with a basal aggregation of leaves; shortly rhizomatous (with fibrous roots), or rhizomatous and tuberous (with root tubers). Mesophytic. Leaves alternate; distichous; flat, or folded; sessile; sheathing. Leaf sheaths not tubular; with free margins. Leaves simple. Lamina entire; linear, or lanceolate; parallel-veined; without cross-venules (?). Lamina margins entire.
Leaf anatomy. Stomata present; anomocytic.
Lamina dorsiventral. The mesophyll containing calcium oxalate crystals, or without calcium oxalate crystals (?). The mesophyll crystals druses (?). Vessels absent.
Stem anatomy. Secondary thickening absent. Xylem without vessels.
Root anatomy. Root xylem with vessels. Vessel end-walls scalariform.
Reproductive type, pollination. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the gynoecium (via septal nectaries).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit cymose. Inflorescences scapiflorous (the scape bracteate); terminal; considered to represent one or two double helicoid cymes (Krause 1930); espatheate. Flowers medium-sized to large (not delimited from the pedicel by a joint); somewhat irregular to very irregular; zygomorphic. The floral irregularity involving the androecium (the stamens upcurved), or involving the perianth and involving the androecium. Flowers 3 merous. Perigone tube present (campanulate or funnelshaped). Hypogynous disk absent.
Perianth of ‘tepals’; 6; joined; 2 whorled; isomerous; petaloid; similar in the two whorls; brick red, or yellow to orange (sometimes striped, but not variegated with a droplike pattern).
Androecium 6. Androecial members adnate (to the perigone tube); markedly unequal; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 6; diplostemonous; long filantherous. Anthers dorsifixed (epipeltate, often twisted); versatile; introrse. Microsporogenesis simultaneous. Tapetum glandular. 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; sessile. Gynoecium stylate. Styles 1; attenuate from the ovary; apical; much longer than the ovary (slender, slightly upcurved). Stigmas 1; truncate, or capitate; wet type. Placentation axile. Ovules 30–50 per locule (‘many’); anatropous; tenuinucellate. Embryo-sac development Polygonum-type. Endosperm formation nuclear.
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (opening from the top). Fruit many seeded. Seeds endospermic; subglobose, prismatic or slightly elongate, not flat. Embryo well differentiated (about the same length as the endosperm). Cotyledons 1. Embryo achlorophyllous (1/1); straight. Testa smooth; encrusted with phytomelan; black.
Seedling. Hypocotyl internode present (short). Seedling collar not conspicuous. Cotyledon hyperphyll compact; non-assimilatory. Coleoptile absent. Seedling cataphylls absent. First leaf dorsiventral.
Physiology, biochemistry. Arthroquinones detected; polyacetate derived. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid absent. Saponins/sapogenins present (steroidal).
Geography, cytology. Holarctic. Boreal and Tethyan. Temperate. Temperate Eurasia, especially Japan. X = 11, the chromosomes not dimorphic, by contrast with Hosta.
Taxonomy. Subclass Monocotyledonae. Superorder Liliiflorae; Asparagales. APG (1998) Monocot; non-commelinoid; Asparagales. Species 16. Genera 1; only genus, Hemerocallis.
Illustrations. • Hemerocallis fulva. • Hemerocallis thunbergii.
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).
