National recovery plan for the Bertya sp. (Cobar-coolabah)
Cunningham & Milthorpe s.n., 2/8/73
NSW National Parks and Wildlife Service , July 2002
ISBN 0 7313 6517 8
3. Description
3.1 General
Scientific Nomenclature: Bertya sp. Cobar-Coolabah (Cunningham and Milthorpe s.n., 2/8/73)
Family: Euphorbiaceae
Bertya sp. Cobar-Coolabah is a slender shrub or small tree to 4 metres high (Harden 1990) that consists of either slender multiple stems or a single trunk up to 70-90 mm in width (NSW Herbarium notes) (Figure 1). The branches and stems are covered with whitish to brown, dense, intertwined hairs.
Leaves are short-stalked, opposite, occasionally alternate, ovate or oblong-elliptical, thick, 10-80 mm long and 5-25 mm wide with margins curved under (Cunningham et al. 1992, NSW Herbarium notes). The upper surface is dark-green and hairless and the under-surface is velvety-woolly.
Flowers lack stalks and have 1-3 female and male flowers clustered together and surrounded by four thick, yellowish to golden brown, hairy bracts. The capsule is ovoid to globose, 8-9 mm long with dense, long weak hairs and contains two to three seeds.
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| Figure 1. Bertya sp. Cobar-Coolabah |
3.2 Taxonomic Significance
Bertya is an endemic genus to Australia, with an estimated 25 species. The genus is found in Queensland, New South Wales and Victoria.
Bertya sp. Cobar-Coolabah was first collected in NSW by G. M. Cunningham in July 1969 in preparation for the publication of 'Plants of Western New South Wales'. In this publication it is described as Bertya oppositifolia (F. Muell. & O'Shanesy) which uses the older taxonomic identity (Cunningham et al. 1992). Harden (1990) lists the species as Bertya sp. Cobar-Coolabah and acknowledges that the identity of this taxon is still unresolved but is either B. opponens (F. Muell. Ex Benth.) Guymer (synonymously known as B. oppositifolia F. Muell. & O'Shanesy) which was previously recorded only from Queensland, or a new closely related species.
The new combination Bertya opponens (F. Muell ex Benth.) Guymer, based on Croton opponens (Bentham 1863-78), was made for the name of the plant described as Bertya oppositifolia F. Muell & O'Shanesy. The holotype of Croton opponens was examined and found to be conspecific with the type of the later Bertya oppositifolia (Guymer 1985).
In 1999, individuals from both the coastal and western populations of Bertya sp. Cobar-Coolabah in NSW were examined by the Queensland Herbarium and considered to be B. opponens (D. Halford pers. comm.). However, although there was no doubt on this identification for the two western populations, fertile material was required from the coastal populations to confirm the identification. Similarly, the National Herbarium of NSW found that the opposite leaves, four conspicuous bracts, four perianth segments, the styles divided up into four lots and the densely villous capsule, as described for Bertya opponens, so closely matched the material of Bertya sp. Cobar-Coolabah that it was difficult to believe that it belonged to a different taxon (Teresa James 1987 in National Herbarium of NSW notes). The Bertya genus in NSW is currently under revision, which will clarify the taxonomic identity of this species (M. Fatemi pers. comm.). It is possible that the two western populations are a different species to the two coastal populations as the tomentum of the latter is considerably more orange (J. Austen pers. comm.).
If all four populations of Bertya sp. Cobar-Coolabah are found to be Bertya opponens, implications will arise at a Commonwealth level but not at a state level as the distribution will still be considered restricted in NSW. However, if the western populations are found to be a different species to the coastal populations then the distribution of Bertya sp. Cobar-Coolabah will be further restricted in the state and the actions contained in this Recovery Plan will need to be reviewed.