Ozothamnus

A genus of about fifty species of evergreen shrubs or weakly woody perennial herbs, confined to the Australasian region. Leaves alternate, often heath-like. Flower-heads resembling those of Helichrysum, usually small, often in dense corymbs. Involucral bracts with dry papery appendages, often conspicuously radiating and simulating the ligules of ray-florets, then usually white; usually a few outer florets female, the rest bisexual, all discoid (ray-florets nil); receptacle without scales. Closely related to Cassinia (from which it differs by the absence of receptacular scales) and Helichrysum, from which no one technical character serves to distinguish it, and in which it is often included as a subgenus.

There is no monographic treatment of the genus, and its taxonomic status is still in need of clarification. The Australian species may be identified by reference to: N. T. Burbidge, ‘A Monographic Study of Helichrysum subgenus Ozothamnus’, in Austr. Journ. Bot., Vol. 6, pp. 229–84 (1958); and those of New Zealand to: H. H. Allan, Flora of New Zealand, Vol. 1, pp. 715–21 (1961).

Footnotes

Revised by C. Jeffrey of the Herbarium, Royal Botanic Gardens, Kew.