Byron Flora and Fauna Study 1999 - Byron Shire Council

A GREENPRINT FOR A SUSTAINABLE FUTURE
Thorny Pea (Desmodium acanthocladum FAMILY FABACEAE)
Introduction. Thorny Pea is a small spiny shrub with ornamental pea-shaped flowers. No Recovery Plan has yet been
prepared.
Conservation status. Thorny Pea is listed on Schedule 2 (Vulnerable) of the TSC Act, 1995 and has a ROTAP code of
2VC- (Briggs and Leigh 1996).
Habit. A shrub to c. 1 m high (Harden 1991).
Flowers. Pink to purple, in clusters at the ends of axillary leafless spines. Flowering in summer (Harden 1991).
Fruit. A pod about 50 mm long (Harden 1991). The pod is sticky and dispersal by adhesion to animal fur is assumed.
Seeds may also be dispersed by flood water.
Habitat. Thorny Pea grows mainly along rivers (Harden 1991), but NPWS Wildlife Atlas records include sites on hill
sides.
Distribution. The Lismore-Grafton region, NSW (Harden 1991). Thorny Pea is also known from the Mt Warning area
in the Tweed (J. Hunter pers. comm.), and parts of the Byron Shire.
Regeneration and horticulture. Seeds are hard-coated as is typical of seeds of many legume species. Scarification is
required for germination.
Economic and cultural significance. No particular use or significance is known apart from the aesthetic and ecological
values of all native species.
Abundance and reservation. In Byron Shire, Thorny Pea occurs in small patches on Coopers Creek, from Wanganui
Gorge and a little downstream. It is also recorded for Tibian Valley and has been recorded on the Wilsons River at
Federal. It occurs in Big Scrub remnants at Booyong and Mortons Scrub and is reserved at Johnstons Scrub NR. Details
of nine records were compiled for the study area. It is inadequately reserved in the Shire, and the adequacy of its overall
reservation is unknown (Briggs and Leigh 1996).
Threats and amelioration. Threats to Thorny Pea include clearing of its riparian habitat and associated habitat modification,
in particular the severe weed infestation characteristic of these environments. Flooding may damage plants and
potential recolonisation sites (but also assist its dispersal). Grazing is a threat to Thorny Pea populations elsewhere in its
range.
To improve the conservation status of Thorny Pea, the health of the populations and their regeneration potential should
be enhanced by weed management and replanting of surrounding habitat. General rehabilitation measures for riparian
environments will benefit Thorny Pea.
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