Alternative names: Not Applicable

Description:
Plants ephemeral, annual or perennial; herbs, subshrubs, shrubs or rarely small trees; leaves simple, opposite, alternate or whorled, exstipulate, entire to pectinate.

Inflorescence usually a spike of solitary flowers or simple or compound dichasia, sometimes compressed into a globular or flat-topped corymb; flowers bisexual or unisexual, actinomorphic, 4-merous, rarely reduced to 3-merous or 2-merous; plants monoecious or dioecious; each flower or dichasium subtended by a pair of bracteoles; sepals usually 4; petals usually 4, usually hooded or boat-shaped; stamens usually 8, rarely 4, anthers ovoid to linear, 4-saccate, basifixed, sometimes apiculate, the filaments usually elongating after anthesis; styles usually 4, free, stigmas usually capitate, fimbriate; ovary inferior, usually completely or incompletely 4-locular with 1 or 2 pendulous ovules in each locule (if 2, then 1 aborts).

fruit an indehiscent nut or schizocarp splitting into 4 mericarps, variously winged or ornamented, 1- or 4-locular with 1 seed per locule.

Distribution:  8 genera and about 150 species, cosmopolitan but with the main centre of diversity in Australia. In Australia 6 genera and 105 species, concentrated in temperate areas, but with some species almost throughout the continent. A few species are minor weeds of agriculture and waterways. For an overall account of the family in Australia see Orchard (in press) Fl. Aust. 18.

Biology: No text

Key to Genera:

1. Fruit an indehiscent nut
2. Fruit usually 4-locular, rarely 1-3-locular, borne in dichasia of 3 or more in the axils of the bracts	HALORAGIS 3.
2. Fruit always 1-locular
3. Fruit more than 3 mm long, in compound dichasia, yellow, showy	GLISCHROCARYON 1.
3. Fruit less than 2 mm long, solitary in the axils of bracts, green, grey or purplish, insignificant	GONOCARPUS 2.
1. Fruit splitting at maturity into 4 l-seeded mericarps	MYRIOPHYLLUM 4.

Author: Prepared by A. E. Orchard