Family Hostaceae

Hostaceae B. Mathew

Alternatively Funkiaceae Horan.~ Liliaceae, Agavaceae and Alliaceae with fibrous or tuberous rootstock

Including Hesperocallidaceae Traub

Habit and leaf form. Herbs (or basally woody). Perennial; with a basal aggregation of leaves; cormous, or rhizomatous (the roots often fleshy). Leaves alternate; spiral; petiolate, or sessile; sheathing. Leaf sheaths with free margins. Leaves simple. Lamina entire; linear to lanceolate, or oblong to ovate; pinnately veined (parallel-pinnate), or parallel-veined. Lamina margins entire.

Leaf anatomy. Stomata present; anomocytic.

Lamina dorsiventral. The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides and solitary-prismatic. Vessels absent.

Stem anatomy. Secondary thickening absent. Xylem without vessels.

Root anatomy. Root xylem with vessels (with scalariform perforation plates).

Reproductive type, pollination. Plants hermaphrodite. Floral nectaries present. Nectar secretion from the gynoecium (from septal nectaries).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes. The ultimate inflorescence unit racemose. Inflorescences scapiflorous; simple scapigerous racemes; espatheate. Flowers bracteate; medium-sized; regular (or nearly so); 3 merous; cyclic; pentacyclic. Perigone tube present (cylindrical, campanulate or funnel-shaped, the lobes of variable length and sometimes recurved). Hypogynous disk absent.

Perianth of ‘tepals’; 6; joined; 2 whorled; isomerous; petaloid; similar in the two whorls; white, or violet, or blue.

Androecium 6. Androecial members adnate (to the perianth tube); free of one another. Androecium exclusively of fertile stamens. Stamens 6. Anthers dehiscing via longitudinal slits; introrse; appendaged. The anther appendages apical (the connective forming a tube over the filament tip). Microsporogenesis successive. Tapetum glandular. Pollen grains aperturate; 1 aperturate; sulcate.

Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil 3 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 3 locular. Gynoecium stylate. Styles 1 (filiform); apical. Stigmas 1; 1 lobed, or 3 lobed; wet type (in Hosta). Placentation axile. Ovules 25–50 per locule (‘many’); anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Synergids pear-shaped (with filiform apparatus). Endosperm formation helobial.

Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Fruit many seeded. Seeds endospermic; small (flattened or compressed, often elliptic). Testa 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. Primary root ephemeral.

Physiology, biochemistry. Proanthocyanidins absent. Flavonols present; kaempferol (abundant, in Hosta). Ellagic acid absent.

Geography, cytology. Holarctic. China, Japan and North America. X = 24, 30.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Liliiflorae; Asparagales. APG 3 core angiosperms; Superorder Lilianae; non-commelinid Monocot; Order Asparagales.

Species 12. Genera 3; Hosta, Leucocrinum (or Anthericaceae), Hesperocallis.

Illustrations.
• Hosta glauca: Bot. Reg. 1839, 50.
• Hosta spp. (Chittenden).