Citation: R. Br., Prod. Fl. Nov. Holl. 496 (1810).

Derivation: Greek thrix, trikhos, hair; desme, a band or bundle; alluding to the twisted hairs or awns which terminate the anthers.

Synonymy: Boraginoides Boehmer in D.C.G. Ludwig, Def. Gen. Pl. edn 3:18 (1760), nom. rej.; Pollichia Medikus, Bot. Beob. 2217 (1784), nom. rej.

Common name: None

Description:
Perennial or sometimes annual shrubs usually sparsely branched, covered with coarse hairs of 2 sizes and spreading to appressed; leaves first opposite and subpetiolate later becoming alternate and sessile.

Inflorescence terminal, with one to several erect scorpioid cymes with flowers loosely arranged each on a pedicel longer than the bracts; sepals connate, one-third to one-half their length, much elongating after flowering; corolla regular, rotate with a tube about as long as the lobes, without scales in the throat, with stamens inserted in the throat and forming a column around the style; stamens with anthers sessile or almost so, with a terminal appendage larger than the anther and twisted around one another; ovary scarcely 4-lobed, with a circular nectary around it, with a style inserted near the apex slender and with an included indistinct terminal stigma.

Fruit with 4 mericarps splitting from the central gynobase; mericarps obovoid, triangular in section, smooth to slightly rough on the inside.

Distribution:  35 species occurring mainly in tropical and subtropical Africa, Asia and Australia; 1 species native to Australia.

Biology: No text

Author: Not yet available