| # The Families of Angiosperms |

L. Watson and M.J. Dallwitz

### Ecdeiocoleaceae Cutler & Airy Shaw

~ Restionaceae.

Habit and leaf form. Rush-like herbs. Switch-plants; with the principal photosynthesizing function transferred to stems. Leaves much reduced. Perennial; with a basal aggregation of leaves; rhizomatous. Xerophytic. Leaves alternate; distichous; membranous (reduced to scales); sessile; sheathing. Leaf sheaths with free margins. Leaves simple; epulvinate. Lamina entire; parallel-veined; without cross-venules. Leaves eligulate.

General anatomy. Plants with silica bodies (as silica sand, in the culm mesophyll). Chlorenchyma including ‘peg cells’.

Leaf anatomy. Epidermis without differentiation into ‘long’ and ‘short’ cells; without silica bodies. Stomata paracytic. Guard-cells ‘grass type’. Lamina without secretory cavities. The mesophyll not containing mucilage cells; without crystals (? — no raphides). Foliar vessels absent.

Axial (stem, wood) anatomy. Young stems cylindrical (grooved, wiry). Secretory cavities absent. Secondary thickening absent.

The vessel end-walls scalariform and simple.

Root anatomy. Root xylem with vessels; vessel end-walls scalariform and simple.

Reproductive type, pollination. Unisexual flowers present. Plants monoecious (male and female flowers in the one spikelet). Female flowers with staminodes (three). Gynoecium of male flowers pistillodial. Floral nectaries absent (nectaries absent). Pollination anemophilous.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in spikes; in effect, in ‘spikelets’. The ultimate inflorescence units racemose. Inflorescences terminal; small, solitary, terminal spikes — constituting spikelets; espatheate (i.e. no basal sheathing bract, by contrast with Restionaceae). Flowers bracteate (with basal ‘glumes’); ebracteolate; minute; 3 merous; cyclic. Perigone tube absent. Hypogynous disk absent.

Perianth of ‘tepals’; 6; free (somewhat unequal); 2 whorled (3+3); isomerous; sepaloid (glumaceous); different in the two whorls (two members of the outer whorl being laterally compressed and ciliate towards their tips).

Androecium of male flowers, 6. Androecial members free of the perianth; all equal; free of one another. Androecium of male flowers exclusively of fertile stamens. Stamens 6; isomerous with the perianth, or diplostemonous; oppositiperianthial. Anthers basifixed; non-versatile; dehiscing via longitudinal slits; tetrasporangiate. Pollen grains aperturate; 1 aperturate; ulcerate. The ulcus operculate; with an annulus. Interapertural exine not scrobiculate. Interapertural interstitium columellate.

Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synovarious; superior. Ovary 2 locular. Styles 2; free; attenuate from the ovary; apical. Stigmas 2 (the styles stigmatic to near the base). Placentation apical. Ovules differentiated; 1 per locule; pendulous; non-arillate; orthotropous. Outer integument contributing to the micropyle. Synergids non-haustorial.

Embryo well differentiated. Testa without phytomelan (?).

Geography, cytology. Western Australia.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Commeliniflorae; Poales. APG III core angiosperms; Superorder Lilianae; commelinid Monocot. APG IV Order Poales.

Species 3. Genera 2; Ecdeiocolea, Georgeantha.

Illustrations. • Ecdeiocolea monostachya, with Dielsia (Restionaceae): Bot. Jharb. 35 (1905).

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: 8th June 2026. delta-intkey.com’.

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