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.
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The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Dillwynia tenuifolia
Profile last updated:
10 Sep 2019
Description
A low spreading pea-flower shrub to a metre high. Its leaves are small and narrow (linear-terete, soft, 4-12mm long, with the tip often bent downwards). The wide orange-yellow and red pea-flowers are usually single, at or near the tips of the branches. Seed pods are brownish, egg-shaped, 4-5mm long with reticulate seeds. Both the singular orange flowers and the stem hairs distinguish it from the similar and more common yellow-flowered Dillwynia glaberrima and D. floribunda.
Distribution
The core distribution is the Cumberland Plain from Windsor and Penrith east to Dean Park near Colebee. Other populations in western Sydney are recorded from Voyager Point and Kemps Creek in the Liverpool LGA, Luddenham in the Penrith LGA and South Maroota in the Baulkham Hills Shire. Disjunct localities outside the Cumberland Plain include the Bulga Mountains at Yengo in the north, and Kurrajong Heights and Woodford in the Lower Blue Mountains.
Habitat and ecology
- In western Sydney, may be locally abundant particularly within scrubby/dry heath areas within Castlereagh Ironbark Forest and Shale Gravel Transition Forest on tertiary alluvium or laterised clays. May also be common in transitional areas where these communities adjoin Castlereagh Scribbly Gum Woodland. At Yengo, is reported to occur in disturbed escarpment woodland on Narrabeen sandstone.
- Eucalyptus fibrosa is usually the dominant canopy species. Eucalyptus globoidea, E. longifolia, E. parramattensis, E. sclerophylla and E. sideroxylon may also be present or codominant, with Melaleuca decora frequently forming a secondary canopy layer. Associated species may include Allocasuarina littoralis, Angophora bakeri, Aristida spp. Banksia spinulosa, Cryptandra spp. Daviesia ulicifolia, Entolasia stricta, Hakea sericea, Lissanthe strigosa, Melaleuca nodosa, Ozothamnus diosmifolius and Themeda australis. D. tenuifolia is often found in association with other threatened species such as Dodonaea falcata, Grevillea juniperina, Micromyrtus minutiflora, Pultenaea parviflora and Styphelia laeta.
At Yengo D. tenuifolia is reported to occur in disturbed escarpment woodland on Narrabeen sandstone. Associated tree species include Eucalyptus eximia, E. punctata, E. sparsifolia and Callitris endlicheri. The shrub layer is dominated by D. tenuifolia, Leucopogon muticus, Leptospermum parvifolium and Pultenaea microphylla (Maryott-Brown & Wilks 1993).
- Flowering occurs sporadically through the year with a peak from from August to March depending on environmental conditions. Pollinators are unknown. The lifespan is estimated to be 20-30 years. It is thought a minimum of 3-4 years is required before seed is produced.
- Seeds are hard coated and are persistent in the soil seed bank. Dispersal is likely to be localised and ants are the probable vectors
- Killed by fire and re-establishes from soil-stored seed.
- Abundance is influenced by past disturbance history e.g. fire. The high population densities at some recorded sites (200,000+ individuals) reflects prolific seed germination in response to fire.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Inappropriate fire regimes, including more than one fire every 5 years leading to seed bank depletion, or less than one fire every 20 years leading to lack of disturbed patches for germination.
- Habitat fragmentation makes individual patches more isolated and also more likely to suffer local fire or other major disturbance.
- Weed invasion of key habitat, including (but not limited to) invasive grasses such as African love grass and Coolatai grass and escaped pine species inhibiting germination and altering fire regimes.
- Partial clearance (e.g. removal or thinning of the canopy) may have a significant impact upon vegetation structure. This can result in dense monospecific regrowth e.g. Allocasuarina littoralis or Melaleuca spp. which out-compete smaller species.
- Loss of key habitat due to increased infrastructure development in the Sydney region.
- Repeated slashing of sites occupied by the species will reduce recruitment by affecting the amount of flowering and seed-set.
- Uncontrolled vehicular access can result in loss through clearing, destruction and the possibly introduction of pathogens and weeds.
- Dumping of materials into accessible patches will reduce the capacity of the species to germinate and grow, or may also cause hotter fires (especially when green-waste dumping occurs).
Recovery strategies
A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.
Activities to assist this species
- Exclude fire from remnants where possible.
- Prevent further loss and fragmentation of habitat.
- Fencing to limit access to sites is recommended, as is the potential to use camera surveillance and signage to reduce the incidence of dumping.
- Removal of dumped materials and restricting access may be valuable to reducing harm to poulations.
- Weed control, using appropriate methods, will be required to manage fuel loads and reduce compettition.
Information sources
- Fairley, A. and Moore, P. (2000) Native plants of the Sydney district: an identification guide. 2nd Edition. (Kangaroo Press, East Roseville)
- Harden, G.J. (ed.) (2002) Flora of New South Wales. Volume 2, Revised Edition. UNSW, Sydney.
- NSW National Parks and Wildlife Service (1997) Urban Bushland Biodiversity Survey. Native Flora of Western Sydney. NSW NPWS, Hurstville.
- Robinson, L. (2003) Field guide to the native plants of Sydney. 3rd Edition. (Kangaroo Press, East Roseville)
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