Family Dysphaniaceae

Dysphaniaceae (Pax) Pax

~ Amaranthaceae, Chenopodiaceae

Habit and leaf form. Small, prostrate herbs. Annual to perennial; with neither basal nor terminal aggregations of leaves. Mesophytic, or xerophytic. Leaves small; alternate; petiolate; non-sheathing; aromatic; simple; epulvinate. Lamina entire. Leaves exstipulate. Lamina margins entire, or crenate. Leaves without a persistent basal meristem.

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

Stem anatomy. Secondary thickening developing from a conventional cambial ring, or anomalous; when anomalous, via concentric cambia. Sieve-tube plastids P-type; type III (c, without a crystal, cf. Chenopodiaceae).

Reproductive type, pollination. 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, biochemistry. Anatomy non-C4 type (Dysphania).

Geography, cytology. Australia.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Caryophylliflorae; Caryophyllales. Cronquist’s Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales (as a synonym of Amaranthaceae).

Species 5. Genera 1; only genus, Dysphania.