The Hermannia Pages:
Western Tar Vine

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The Western Tar Vine of the Australian interior is classified by the Australian National Botanic Garden and other Australian organisations in the monotypic genus Gilesia, as Gilesia biniflora F. Mueller. Elsewhere, including the recent revision of Malvaceae by Clemens Bayer, Gilesia is included within Hermannia, a genus otherwise nearly confined to Africa, but with one species extending to Arabia, and three species in northern Mexico and adjacent parts of the United States.

The only name I know for the plant in Hermannia, is Hermannia gilesii F. Mueller, but this is a provisional name later rejected by the author, and is invalid. The plant has also been described as Corchorus longipes Tate and Hymenocapsa longipes (Tate) J. M. Black, but Gilesia biniflora has priority. Hence I deduce that the correct name is Hermannia biniflora (F. Mueller) A. N. Other, but I am unaware of any formal publication of this combination. (It is absent from Index Kewensis and the Australian Plant Name Index.)

Gilesia biniflora does differ from the generality of Hermannia species in its prostate habit and white flowers, but these characters do not warrant generic rank, nor do I know that they do not occur in Hermannia.

Gilesia was named to honour Ernest Giles, a 19th Century Australian explorer. The single species, Gilesia biniflora F. Mueller, is found in central Australia.

Gilesia is also a rejected name for a genus of mosquito.

Gilesia biniflora F. Mueller
Australian Flag Western Tar Vine

Gilesia biniflora is found in the central regions of Australia, in the interiors of New South Wales, South Australia, Western Australia and the Northern Territory, typically on saline clay soils. It is a prostrate perennial herb, with wiry stems and a spread of 40 to 60 cm. It bears small (0.5cm diameter), white, 5-petalled flowers, in late spring and early summer, and sporadically throughout the remainder of the year, singly or in pairs, on slender axillary stalks. The fruit is a 5-celled capsule, about 6mm long. The leaves are broadly toothed, oblong-lanceolate in shape, 1-2 cm long, and 1 cm wide. The stems, fruits, and immature leaves are tomentose.


  1. W. Rodger Elliot and David L. Jones, Encyclopaedia of Australian Plants suitable for cultivation. Vol. 4
  2. Kubitzki and Bayer, The Families and Genera of Vascular Plants, Vol. 5
  3. Cowie & Albrecht (eds.), Checklist of NT Vascular Plant Species (2005)


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