Bolivia Hill Boronia - profile

Indicative distribution

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Key:

known

predicted

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: Boronia boliviensis

Conservation status in NSW: Critically Endangered

Commonwealth status: Critically Endangered

Gazetted date: 15 Dec 2023

Profile last updated: 19 Nov 2024

Description

This pretty shrub grows to 2.5 m high. The dark green leaves are divided into 5 - 9 leaflets which are 4 - 8 mm long. They are covered by a scattering of short hairs on the upper surface. The branches are covered in fine yellow hairs. The deep pink flower clusters, which occur from spring through to summer, are held at the base of the leaves.

Distribution

Bolivia Hill Boronia occurs primarily in Bolivia Hill Nature Reserve south of Tenterfield. The population was estimated at 1000 mature plants in 1999, reportedly decreasing during the subsequent decade. However, new sub-populations were discovered with more extensive field work, including one very large patch. The drought of 2018-2019 led to severe grazing by macropods and a major reduction in mature plants. Subsequent rains have stimulated seedlings but competition with Boronia anethifolia, which was not as greatly reduced by grazing, may hinder a return to prior abundance in some patches. A previous record near Demon Nature Reserve has been subsequently identified as Boronia granitica.

Habitat and ecology

Reproduces primarily during spring but flowers have been observed in all seasons. Longevity has been estimated to be about 15 years.
Grows in dry sclerophyll forest amongst granite boulders. The species also grows in heathland on shallow soil in the cracks of granite outcrops.
Associated species in heath habitats include Acacia adunca, Acacia pycnostachya, Leptospermum microcarpum, Leptospermum brevipes, Notelaea linearis, Homoranthus croftianus, Boronia anethifolia and Kunzea bracteolata. Dry sclerophyll forest vegetation comprises Eucalyptus prava, Eucalyptus andrewsii and Callitris endlicheri.
Recruitment cues other than fire, such as soil disturbance, have been suggested in the establishment of new cohorts. For instance, a very extensive recruitment event occurred during 2021 across numerous unburnt patches, where the probable trigger was abundant rainfall following severe drought.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

New England Tablelands

Threats

Too frequent fire that may kill adult plants and deplete the soil-stored seed.
Browsing by feral goats, and associated trampling, soil compaction and nutrient addition.
The species is heavily grazed by kangaroos and wallabies when other forage becomes unavailable, such as during severe droughts.
Vulnerable to localised catastrophic events which could reduce the number of populations.
Spraying or slashing during powerline easement maintenance.

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

Assist with the control of feral goats.
Protect areas of rocky heathland and shrubby open forest habitat from frequent fire.
Protect trackside and easement populations during maintenance work.
Report any new records of Bolivia Hill Boronia to the OEH.
Identify and map all populations.

Information sources

Briggs, J.D. and Leigh, J.H. (1996) Rare or Threatened Australian Plants. Revised Edition. (CSIRO Publishing, Melbourne)
Hunter, J.T. and Clarke, P.J. (1998) The vegetation of granitic outcrop communities on the New England Batholith of eastern Australia. Cunninghamia 5(3): 547-618
Martyn, A.J., Seed, L.U., Ooi, M.K.J. and Offord, C.A. (2009) Seed fill, viability and germination of NSW species in the family Rutaceae. Cunninghamia 11(2): 203–212
Morsley, R. and Falconer, S. (1999) Boronia boliviensis (Bolivia Hill Boronia) Draft Recovery Plan (World Wide Fund for Nature (WWF), Rural Nature Conservation Project, Armidale)
NSW National Parks and Wildlife Service (2002) Recovery Plan for Boronia granitica (Granite Boronia). (NSW NPWS, Hurstville)
NSW National Parks and Wildlife Service (2003) Threatened Species of the New England Tablelands and North West Slopes of NSW. (NSW NPWS, Coffs Harbour)
Quinn, F., Williams, J.B., Gross, C.L. and Bruhl, J. (1995) Report on Rare and Threatened Plants of north-eastern New South Wales. Report prepared for the New South Wales National Parks and Wildlife Service and the Australian Nature Conservation Agency.
Weston, P.H. and Duretto, M.F. (2002) Boronia. Pp. 265-275 in Harden, G.J. (ed.) Flora of New South Wales. Revised Edition Volume 2. (University of New South Wales Press Ltd, Sydney)
William, J.B. and Hunter, J.T. (2006) Boronia boliviensis (Rutaceae series Erianthae), a new rare granite outcrop endemic from north-eastern New South Wales. Telopea 11(3): 260-4

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

New England Tablelands	Deepwater Downs	Predicted	None
New England Tablelands	Northeast Forest Lands	Predicted	None
New England Tablelands	Tenterfield Plateau	Known	None