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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3.25 parsonsia kroombitensis J.B. Williams3.25.1 SummaryParsonsia kroombitensis is endemic to south east Queensland where it is recorded from the Calliope and Boyne Ranges, approximately 80 km south west of Gladstone and from the Cania Gorge National Park near Monto. The distribution of P. kroombitensis has a range of approximately 70 km and encompasses an area of approximately 1300 km2. There is no quantitative data on populations. It grows on escarpments at the edges of deep valleys, among outcrops, in low shrubby woodland or open shrubland communities at altitudes from 120 to 860 m. A perceived threat to the continued survival of Parsonsia kroombitensis in the wild is an inappropriate fire regime. 3.25.2 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 kroombitensis was formally described in 1996 from material collected at Kroombit Tops, approximately 59 km south west of Gladstone. The botanical description of Parsonsia kroombitensis is as follows: Climber to 2 m high, often in clumps pendent from rock crevices; stems minutely puberulous; latex clear. Leaves glabrous or lower surface minutely puberulous, dark purple or purplish brown when dried; petiole 3-7 mm long; lamina lanceolate, linear-lanceolate or deltoid, 2-6 cm long, 0.6-1.9 cm wide, rounded, truncate, cordate or cuneate at base, recurved marginally, acuminate, apiculate. Inflorescence of axillary, occasionally terminal, open cymes with 2-9 flowers; pedicels 2-15 mm long. Corolla orange-yellow, red in throat and at base of lobes, white on margins of lobes; tube cylindrical, 4.5 mm long, conspicuously bearded at throat with glistening hairs; lobes spreading, recurved near apex, narrowly obovate with a thickened median strip, 4-5 mm long, 2.8 mm wide, glabrous. Capsules very narrowly ovoid, 4-10 cm long, 0.7-1 cm diameter, glabrous or puberulous (Williams 1996). Parsonsia kroombitensis is distinguished by all parts becoming dark purple or purplish brown when dry; small to very small, lanceolate or deltoid, acuminate leaves, with rounded-truncate, cordate or cuneate base, with main veins impressed above and a little raised below; broad, recurved corolla lobes that are orange with a white margin and red base; a beard of glistening hairs at the corolla throat; and the red, 2/3-exserted anther cone and the straight filaments (Williams 1996). 3.25.3 Current conservation statusParsonsia kroombitensis is presently not listed on the schedule of the Queensland Nature Conservation Act 1992. It is not currently assigned a national conservation status or listed on the Commonwealth Endangered Species Protection Act 1992. However, 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. A too frequent fire regime is considered a potential threat to the long-term survival of the species. 3.25.4 Distribution and abundanceDetails from Queensland Herbarium specimens of Parsonsia kroombitensis are listed in Appendix 1.24. The species is known from four collections from state forest lands in the Calliope and Boyne Ranges, approximately 80 km south west of Gladstone. It also occurs in the Cania Gorge National Park (J. Brushe pers. comm.). There is no quantitative data available on populations. Anecdotal evidence suggests that it is not common at the sites where it has been observed (J. Brushe pers. comm.). The distribution of P. kroombitensis has a range of approximately 70 km and encompasses an area of approximately 1300 km2. 3.25.5 HabitatP. kroombitensis grows on escarpments at the edges of deep valleys, among outcrops of acid volcanic rock, in low shrubby woodland of Eucalyptus acmenoides and Corymbia trachyphloia on metamorphosed sandstone, in open woodlands of E. eugenioides, E. montivaga and E. longirostrata in brown gravelly loam on mudstone and in open shrubland and among lithophytic vegetation at altitudes from 120 to 860 m. 3.25.6 Life history and ecologyThere have been no studies into the biology or autecology of P. kroombitensis. A number of the more common species of Parsonsia have been propagated by cuttings and seed (Wrigley & Fagg 1996). P. kroombitensis 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. kroombitensis has been recorded flowering in February and March and fruiting in July and September. Seeds of P. kroombitensis mature the same year of flowering. The seeds are adapted for dispersal by air currents, being relatively light in weight with a plume of long hairs. The longevity and viability of the seed is unknown. P. kroombitensis’ 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. 3.25.7 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 kroombitensis 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 of being 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. 3.25.8 Management, research and conservation measuresPreviously recorded sites should be examined to establish the size and extent of the populations. 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. kroombitensis are warranted, particularly the species’ response to fire and habitat disturbance. |