Alternative names: Not Applicable
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.
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).
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.
Prepared by W. R. Barker