Survey of threatened plant species in South East Queensland biogeographical region queensland cra/rfa steering committee survey of threatened plant species in
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3.26 parsonsia larcomensis J.B. Williams3.26.1 SummaryParsonsia larcomensis is endemic to central and south east Queensland where it is recorded from three mountain peaks, Mt Wheeler (near Rockhampton), Mt Larcom (near Gladstone) and Mt Perry (near Bundaberg) and one riverine habitat near Byfield. The distribution of P. larcomensis has a range of approximately 280 km. It is recorded from TR 157 Fty 1077 (Mt Perry) and is not recorded in any conservation reserve. There is no quantitative data on populations. It grows mostly on shallow loamy soils on cliff lines and exposed outcrops of trachyte rocks at or near mountain summits. A perceived threat to the continued survival of Parsonsia kroombitensis in the wild is an inappropriate fire regime. 3.26.2 Species description and identificationThe genus Parsonsia is placed in the family Apocynaceae. Parsonsia has approximately 130 species distributed from south east Asia to Australia, New Zealand and parts of the south-western Pacific (Williams 1996). In Australia, 35 species are distributed across northern and eastern parts of the continent. Parsonsia larcomensis was formally described in 1996 from material collected from Mt Larcom, approximately 20 km west north west of Gladstone. The botanical description of Parsonsia larcomensis is as follows: Prostrate, creeping, more or less glabrous semi-woody plants to 5 m long, attached to rocks or soil by adventitious roots; latex clear. Leaves coriaceous, glabrous; petiole 3-7 mm long; lamina ovate to broadly elliptic, 1.1-4.5 cm long, 1-2.2 cm wide, rounded or cordate at base, shortly acuminate or acute, apiculate, green above, glaucous below. Inflorescence of axillary and terminal panicles, with 5-12 flowers, pedicels 3-5 mm long. Calyx lobes narrow, 4.5-5 mm long, Corolla whitish, with 5 red spots in throat; tube narrowly funnel-shaped, 7.5-8 mm long, glabrous or puberulous internally but not bearded; lobes spreading to recurved, lanceolate or narrowly deltoid, 2-3 mm long, acute, puberulous externally glabrous internally. Capsules slender, terete-fusiform, 7-11 cm long, 0.5-1.1 cm diameter, brown, puberulous (Williams 1996). Parsonsia larcomensis resembles P. straminea but can be distinguished by its smaller capsules and a number of floral features. The differences are presented in Table 3.26.1. Table 3.26.1. Characters distinguishing parsonsia larcomensis and Parsonsia straminea
3.26.3 Current conservation statusParsonsia larcomensis is presently not listed on the schedule of the Queensland Nature Conservation 1992. It is listed on Schedule 1 Part 2 (vulnerable) of the Commonwealth Endangered Species Protection Act 1992. Its inclusion on the Queensland Schedule of threatened wildlife as ‘Vulnerable’ is currently pending. It is to be added to the schedule because it has a restricted distribution and is not in any formal conservation reserve. Potential threats are believed to be fire and weed competition. 3.26.4 Distribution and abundanceDetails from Queensland Herbarium specimens of Parsonsia larcomensis are listed in Appendix 1.25. The species is known from seven collections from four localities, Upper Stoney, approximately 15 km west of Byfield, Mt Wheeler, approximately 20 north east of Rockhampton, Mt Larcom approximately 20 north west of Gladstone and Mt Perry approximately 80 km west south west of Bundaberg. The Mt Perry site is within TR 157 (Fty 1077). The Upper Stoney site is within the Shoalwater Bay Military Training Area. The other two localities are on freehold land. The species is not recorded in any conservation reserve. There is no quantitative data available on population sizes. However, it has been reported as being rare or common at collection sites. The distribution of P. larcomensis has a range of approximately 280 km. Three of the four localities are outside the South East Queensland Biogeographical Region. 3.26.5 HabitatP. larcomensis grows on shallow loamy soils on cliff lines and exposed outcrops of trachyte rocks at or near the summit of mountains. It is also recorded in a gully at base of rock face in Eucalyptus fibrosa woodland on serpentinite rocks. 3.26.6 Life history and ecologyThere have been no studies into the biology or autecology of P. larcomensis. A number of the more common species of Parsonsia have been propagated by cuttings and seed (Wrigley & Fagg 1996). P. larcomensis is a perennial climber that reproduces by sexually produced seeds. There is no indication that the species can reproduce vegetatively. The longevity of the plants is unknown. P. larcomensis has been recorded flowering in January, February, May and August and fruiting in July and September. Fruits of P. larcomensis mature approximately 2 months after flowering. The mature pod splits to release the seed. The seeds are adapted for dispersal by air currents. The longevity and viability of the seed is unknown. P. larcomensis’ response to fire is unknown. The above-ground biomass is probably killed by fire. It does not appear to have a lignotuber or have the capability of resprouting from the stem base. The continued existence of this species after fire would rely on successful seedling recruitment. 3.26.7 ThreatsWith our limited knowledge of the species it is difficult to determine the stability of the populations and what possible threats there are to the long term existence of Parsonsia larcomensis in the wild. Fires are either unplanned (wildfires from lighting strikes) or planned (hazard reduction burns). The lack of ecological information about this species response to fire makes it impossible to assess what would be an appropriate level of frequency and intensity for the long term benefit of the species. The species is suspected to be fire-sensitive and incapable of regenerating from underground organs. The continued existence of the species in the wild after a fire would require the regeneration of the species from seed (obligate seeder). If fires were at a frequency that did not allow the production of adequate seed for future recruitment events then the population would decline and the species would be eliminated from the area. This is a potential threat at all sites. However, the habitat in which the species has been observed provides some degree of protection from frequent burning in that the rocky outcrops may buffer plants from fires. 3.26.8 Management, research and conservation measuresPreviously recorded sites should be examined to establish the population sizes and extent. Areas of likely habitat in the vicinity of the known populations should be searched for further occurrences. Very little is known about this species. Investigations into the ecology of P. larcomensis are warranted, particularly the species’ response to fire and habitat disturbance. For those populations that occur on freehold land, liaison with land owners should be undertaken to make them aware of the presence of the species and the importance of protecting the populations. Discussions should be undertaken with the land holders in regard to protecting the areas with Conservation Agreements under the Queensland Nature Conservation Act 1992. |