Citation: Desf., Mém. Mus. Hist. Nat. Paris 6:16 (1820).

Derivation: Greek gyros, a circle; stemdn, a stamen; alluding to the whorled stamens.

Synonymy: Not Applicable

Common name: None

Description:
Shrubs or trees, dioecious, glabrous; leaves alternate, sessile, with small setose stipules.

Inflorescence rarely of reduced racemes or more often of single flowers in the axil of leaves towards the apex of leafy branches; male flowers with a calyx with few to many lobes forming a saucer- or cup-shaped tube around the few to numerous sessile anthers in 1 or more whorls spreading or clustered around the central axis; female flowers with a lobed cup-shaped calyx tube, with 1-30 carpels in 1 row around the central axis and each with an elongate papillose stigma.

Fruit spherical or almost round in side view, with dry follicles dehiscing along the dorsal ridge but often deciduous before the single seed is shed; central axis cylindrical or almost so.

Distribution:  12 species; endemic to mainly southern temperate Australia with the central arid areas well represented.

Biology: No text

Taxonomic notes: George (1982) included the species of Didymotheca in Gyrostemon as an almost complete range of numbers of carpels from 1-30 per female flower has been recorded since the former genus was established.

Key to Species:

1. Stamens in more than 1 whorl; carpels 17-33; leaves usually more than c.3 cm long	G. ramulosus 2.
1. Stamens in 1 whorl; carpels 1-7; leaves rarely more than c.3 cm long
2. Male and some female flowers in short racemes with 1-3 flowers; LE region	G. tepperi 3.
2. Male and female flowers borne only on a pedicel in the axils of leaves; southern regions of S.Aust
3. Stems terete and without distinct ridges when young; carpels 4-7 per female flower	G. australasicus 1.
3. Stems usually with decurrent ridges from the leaf bases when young; carpels 1 or 2 per female flower	G. thesioides 4.

Author: Not yet available