The families of flowering plants

L. Watson and M.J. Dallwitz

Dysphaniaceae (Pax) Pax

~ Amaranthaceae, Chenopodiaceae.

Habit and leaf form. Small, prostrate herbs. Annual to perennial; without conspicuous aggregations of leaves. Mesophytic, or xerophytic. Leaves small; alternate; petiolate; non-sheathing; aromatic; simple; epulvinate. Lamina entire. Leaves exstipulate. Lamina margins entire, or crenate. Leaf development not ‘graminaceous’.

Leaf anatomy. Stomata present; diacytic (?). Hairs present; glandular, or eglandular and glandular.

Axial (stem, wood) anatomy. Secondary thickening developing from a conventional cambial ring, or anomalous. The anomalous secondary thickening when present, via concentric cambia.

Reproductive type, pollination. Unisexual flowers present. Plants gynomonoecious, or monoecious, or polygamomonoecious (?).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in fascicles and in spikes. Inflorescences terminal, or axillary; fasciculate, or crowded and spicate. Flowers minute. Hypogynous disk absent.

Perianth sepaline; (1–)3–4; free, or joined (basally); 1 whorled; accrescent. Calyx (if perianth so interpreted) (1–)3–4; polysepalous, or gamosepalous (basally); persistent; accrescent (surrounding the fruit, becoming winged); valvate.

Androecium 1(–2). Androecial members free of the perianth; free of one another (exserted); 1 whorled. Androecium exclusively of fertile stamens. Stamens 1, or 2; reduced in number relative to the adjacent perianth to isomerous with the perianth; oppositisepalous. Anthers introrse. Pollen grains aperturate; 13–50 aperturate (?); (poly) foraminate.

Gynoecium (2–)3 carpelled. The pistil 1 celled. Gynoecium syncarpous; synovarious, or synstylovarious; superior. Ovary 1 locular. Styles 1, or 2; apical. Ovules in the single cavity 1; non-arillate; hemianatropous (?).

Fruit non-fleshy; indehiscent; a nut (surrounded by the broadly winged perianth). Seeds non-endospermic (?). Perisperm present (?). Embryo well differentiated. Embryo curved (‘circular, surrounding the endosperm’).

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. Anatomy non-C4 type (Dysphania). Sieve-tube plastids P-type; type III (without a crystal, cf. Chenopodiaceae).

Geography, cytology. Australia.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG III core angiosperms; core eudicot; Superorder Caryophyllanae. APG IV Order Caryophyllales (as a synonym of Amaranthaceae).

Species 5. Genera 1; only genus, Dysphania.

General remarks. In terms of the data compiled here, Dysphania differ from Amaranthaceae sensu stricto (q.v.) in being aromatic, without betalains, and lack of crystal sand in the tissues, as well as in the valvate calyx, free androecial members, and hemianatropous ovules.

Illustrations. • Dysphania simulans: von Mueller & Tate (1885).

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: 5th March 2018.’.