Alternative names: Not Applicable

Description:
Herbs with ribbed branches; leaves alternate, simple, entire; stipules tiny, terete, sometimes caducous.

inflorescence terminal, usually racemose or spike-like, rarely (outside S.Aust.) paniculate or umbelliform or the flowers solitary; flowers actinomorphic or zygomorphic, bisexual, often subtended by small bracts with smaller bracteoles borne laterally on the pedicel; hypanthium short or cup-shaped; sepals 5, free; petals 5, free or fused in the middle into a tube; stamens 5, free; anthers 2-locular, dehiscing by longitudinal slits; ovary superior; carpels 3-5, 1-ovulate, united along a central axis; style 1, sometimes (Macgregoria) surrounded at the base by a cup, terminated by 3-5 terete stigmas.

fruit a schizocarp with up to 5 nutlets (cocci); hypanthium and ovary axis persistent; seeds erect; endosperm fleshy; embryo straight.

Distribution:  A small predominantly Australian family of 3 genera and at least 19 species, 1 species extending to Malesia and Micronesia and another endemic in New Zealand; only Stackhousia in S.Aust. (W. R. Barker (1977 & 78) Taxonomic studies in Stackhousia Smith (Stackhousiaceae) in South Australia. J. Adelaide Bot. Gard. 1:69-82 & 200; W. R. Barker (1984) Fl. Aust. 22:185-200, 203).

Biology: No text

Taxonomic notes: Tripterococcus is confined to south-west W.Aust., and Macgregoria, included by J. Black in his Fl.S. Aust. 358 (1952), occurs in adjacent arid central Australia but does not extend into S.Aust.

Author: Prepared by W. R. Barker