Family Cartonemataceae

Cartonemataceae Pichon

~ Commelinaceae

Habit and leaf form. Herbs. Plants non-succulent (by contrast with Commelinaceae). Perennial; rhizomatous, or tuberous. Mesophytic, or xerophytic. Leaves deciduous; alternate; spiral; ‘herbaceous’; sessile; sheathing; simple. Lamina entire; linear; parallel-veined; without cross-venules. Leaves with a persistent basal meristem, and basipetal development.

General anatomy. Plants with silica bodies, or without silica bodies.

Leaf anatomy. The mesophyll without calcium oxalate crystals. Vessels present (Triceratella), or absent (Cartonema); end-walls scalariform.

Stem anatomy. Secondary thickening absent. Xylem with vessels (Triceratella), or without vessels (Cartonema). Vessel end-walls scalariform.

Root anatomy. Root xylem with vessels; vessel end-walls reticulately perforated.

Reproductive type, pollination. Plants hermaphrodite. Floral nectaries absent (nectaries lacking). Pollination entomophilous (but without nectar).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes and in spikes. The ultimate inflorescence unit racemose. Inflorescences terminal, or axillary, or leaf-opposed; simple or branched spikes or racemes. Flowers regular; 3 merous; cyclic; pentacyclic. Perigone tube absent.

Perianth with distinct calyx and corolla; 6; free; 2 whorled; isomerous; different in the two whorls; yellow. Calyx 3; 1 whorled; gamosepalous. Corolla 3; 1 whorled; polypetalous; yellow; persistent (marcescent).

Androecium 6. Androecial members free of the perianth; all equal; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 6; diplostemonous. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Microsporogenesis successive. Pollen grains aperturate; 1 aperturate; sulcate; 2-celled.

Gynoecium 3 carpelled. The pistil 3 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 3 locular. Styles 1; apical. Stigmas 1; capitate. Placentation axile. Ovules 2 per locule; superposed; non-arillate; anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Endosperm formation nuclear. Embryogeny asterad.

Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal. Seeds endospermic. Endosperm not oily (mealy). Embryo weakly differentiated. Cotyledons 1. Testa operculate (with an ‘embryostega’, covering the embryo); without phytomelan.

Seedling. Hypocotyl internode absent. Mesocotyl present (at least in Cartonema). Seedling collar not conspicuous. Cotyledon hyperphyll compact; non-assimilatory. Coleoptile present. Seedling cataphylls absent. First leaf dorsiventral. Primary root ephemeral.

Physiology, biochemistry. C3.

Geography, cytology. Tropical. Australia.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Commeliniflorae; Commelinales. APG 3 core angiosperms; Superorder Lilianae; commelinid Monocot; Order Commelinales (as a synonym of Commelinaceae?).

Species 6. Genera 2; Cartonema, Triceratella.