Indicative distribution
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas.
(
click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Tetratheca glandulosa
Profile last updated:
17 Jan 2023
Description
Small, spreading shrub which grows 20 - 50cm in height. Stems often become entwined among other small shrubs, sedges and grasses. Leaves are opposite 5 - 10 mm long and 1 mm wide with recurved (rolled under) margins. Leaf margins have small stiff hairs that give them a “toothed” appearance. The flower stalk and sepals (leaf-like structure at base of flower) are covered with dark-red gland-tipped hairs, which distinguishes T. glandulosa from other Tetratheca species. T. glandulosa flowers have four petals, which are dark pink, or occasionally pale pink. The flower stalk is 3 - 10 mm long and the petals are approximately 4.5 - 10.5 mm long.
Distribution
Restricted to the following Local Government Areas: The Hills Shire, Gosford, Hawkesbury, Hornsby, Ku-ring-gai, Northern Beaches, Ryde and Wyong. There are approximately 150 populations of this plant ranging from Sampons Pass (Yengo NP) in the north to West Pymble (Lane Cove NP) in the south. The eastern limit is at Ingleside (Northern Beaches LGA) and the western limit is at East Kurrajong (Wollemi NP). There are historical collections of this species south to Manly, Willoughby and Mosman, however these populations are now extinct. The current north-south range is approximately 65km.
Habitat and ecology
- Associated with shale-sandstone transition habitat where shale-cappings occur over sandstone, with associated soil landscapes such as Lucas Heights, Gymea, Lambert and Faulconbridge. Topographically, the plant occupies ridgetops, upper-slopes and to a lesser extent mid-slope sandstone benches. Soils are generally shallow, consisting of a yellow, clayey/sandy loam. Stony lateritic fragments are also common in the soil profile on many of these ridgetops.
- Vegetation structure varies from heaths and scrub to woodlands/open woodlands, and open forest. Vegetation communities correspond broadly to Benson & Howell’s Sydney Sandstone Ridgetop Woodland (Map Unit 10ar). Common woodland tree species include: Corymbia gummifera, C. eximia, Eucalyptus haemastoma, E. punctata, E. racemosa, and/or E. sparsifolia, with an understorey dominated by species from the families Proteaceae, Fabaceae, and Epacridaceae.
- Flowers July-November however residual flowers may persist until late December. Flowering influenced by seasonal weather conditions and/or the microclimate effects (eg. exposure) of each particular site.
- The age of individual plants is difficult to determine and the life span of the plant is unknown. Life expectancy is approximately six to ten years, however, based on field investigations which indicate that the plant resprouts from a woody root following fire, this may be an underestimate.
- The breeding system for this species is poorly known. In comparison to a similar species, Tetratheca juncea, it is expected that this plant is unable to self-pollinate due to the physical characteristics of the plant’s reproductive parts, and that a pollen vector (possibly a species of native bee) is required for successful pollination.
- Seedbank dynamics (fecundity, viability, dispersal, longevity, dormancy etc) for this species are poorly known. Juveniles appear to be uncommon within any given population, with the majority of plants usually consisting of resprouting adults.
- Resprouts from a woody root following fire, however the role fire plays in seed germination and persistence of the species is unclear. In a similar species, Tetratheca hirsuta, it has been shown that exposure of the seed to cold smoke and/or smoked water derived from burnt native vegetation promoted germination.
- Field observations following fire indicate that the plant is likely to be clonal.
- Tetratheca species are reported to be readily propagated by cuttings, however the long term survival of these plants is poorly known.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Habitat loss through vegetation clearing and habitat degradation.
- Fire control activities, particularly frequent prescribed burning and mechanical fuel reduction, and the construction/maintenance of fire access tracks.
- Habitat fragmentation of small, isolated populations.
- Competition from weeds - African love grass, kikuyu and Coolatai grass.
- Full extent of population unknown.
- Habitat loss through vegetation maintenance for utilities and roads.
Recovery strategies
Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological
community. The Office of Environment and Heritage has identified
16 priority actions
to help recover the Tetratheca glandulosa in New South Wales.
Activities to assist this species
- Development in or adjacent to populations should ensure that sufficient vegetative buffers exist to prevent habitat degradation and maintain habitat connectivity.
- Minimise habitat loss (in particular vegetation clearance within large populations and those at the edge of the species range).
- Maintain and improve habitat connectivity within and among populations.
- Restore degraded habitat using bush regeneration techniques.
- Minimise and/or prevent factors which promote habitat degradation (eg. large edge-area ratios, urban/agricultural runoff and stormwater, unrestricted access etc).
Information sources
- Benson, D. and Howell, J. (1994) The natural vegetation of the Sydney 1:100000 map sheet. Cunninghamia 3(4): 679-789.
- Chapman, G.A. and Murphy, C.L. (1989) Soil Landscapes of the Sydney 1:100000 mapsheet. Soil Conservation Service of NSW., Sydney.
- Dixon, K.W., Roche, S. and Pate, J.S. (1995) The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants. Oecologia 101:185-192.
- Harden, G.J. (ed.) (1992) Flora of New South Wales Vol. 3. UNSW Press, Kensington, NSW.
- Maryott-Brown, K. & Wilks, D. (1993) Rare and endangered plants of Yengo National Park and adjacent areas. Unpublished report for the NPWS, Sydney.
- Payne, R.J. (2000) Lake Macquarie Tetratheca juncea conservation management plan. Final report. November 2000. Unpublished report to Lake Macquarie City Council, NPWS and BHP Pty Ltd
- Thompson, J. (1976) A revision of the genus Tetratheca (Tremandraceae). Telopea 1(3): 139-215.
- Wrigley, J.W. and Fagg, M. (1996) Australian Native Plants. Reed Books, Frenchs Forest.
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