Publication Date
1989
Description
In Australia Hypericum perforatum (St. John's wort) is a major weed of pastures because it replaces useful vegetation, causes photosensitisation in grazing animals, depresses their central nervous system and renders them hypersensitive to temperature change and handling (Campbell and Delfosse, 1984). H. perforatum infested 188,000 ha in New South Wales (N.S.W.) in 1976, (Campbell, 1977) and 173,000 ha in Victoria in 1983 (Shepherd, 1983). Specimens of H. perforatum collected in 1929 in N.S.W., Victoria and South Australia were classed as the narrow leaved var. angustifolium De Candolle (Calvert, 1930, 1932) at the Royal Botanic Gardens, Kew (B. Mathew, pers. comm. 1983). As a result it was accepted that var. angustifolium was the only one in Australia. However, more recently, differences noted between plants of H. perforatum suggest that other varieties may be present. In Europe varieties of H. perforatum have broad leaves (var. perforatum, northern Europe), narrow leaves (var. angu stifolium, southern Europe), intermediate leaves (hybrids?) or small leaves (var. microphyllum) (Robson, 1967, 1968). To investigate whether these varieties occur in N.S.W., specimens were collected from various locations, grown in a common environment at Bathurst, and observed over time.
Citation
Campbell, M H.; May, C E.; Southwell, I A.; and Tomlinson, J D., "Variation in Hypericum perforatum L. in Australia" (2025). IGC Proceedings (1989-2023). 1.
https://uknowledge.uky.edu/igc/1989/session6/1
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Variation in Hypericum perforatum L. in Australia
In Australia Hypericum perforatum (St. John's wort) is a major weed of pastures because it replaces useful vegetation, causes photosensitisation in grazing animals, depresses their central nervous system and renders them hypersensitive to temperature change and handling (Campbell and Delfosse, 1984). H. perforatum infested 188,000 ha in New South Wales (N.S.W.) in 1976, (Campbell, 1977) and 173,000 ha in Victoria in 1983 (Shepherd, 1983). Specimens of H. perforatum collected in 1929 in N.S.W., Victoria and South Australia were classed as the narrow leaved var. angustifolium De Candolle (Calvert, 1930, 1932) at the Royal Botanic Gardens, Kew (B. Mathew, pers. comm. 1983). As a result it was accepted that var. angustifolium was the only one in Australia. However, more recently, differences noted between plants of H. perforatum suggest that other varieties may be present. In Europe varieties of H. perforatum have broad leaves (var. perforatum, northern Europe), narrow leaves (var. angu stifolium, southern Europe), intermediate leaves (hybrids?) or small leaves (var. microphyllum) (Robson, 1967, 1968). To investigate whether these varieties occur in N.S.W., specimens were collected from various locations, grown in a common environment at Bathurst, and observed over time.
