National recovery plan for Tuggeranong Lignum (Muehlenbeckia tuggeranong)
A Recovery Plan under the Environment Protection and Biodiversity Conservation Act 1999 (Cwlth), based on an Action Plan (Action Plan No. 24) prepared for the species under the Nature Conservation Act 1980 (ACT).
1. Species description and ecolog
The Tuggeranong Lignum Muehlenbeckia tuggeranong Mallinson (Figure 1) is a sprawling or procumbent shrub, eventually becoming a mounded loosely tangled mass to approximately 1high and 12across. Stems are wiry, brownish, and weakly and irregularly longitudinally striate. Leaves are alternate, persistent, green, not glaucous, simple, petiolate, solitary and well spaced along the stems. Petioles are 0.5 to 3mm long and leaf blades 513long by 24wide, showing considerable variation in form. Inflorescences are terminal (sometimes on short lateral branches) or very rarely axillary, simple or 2-branched; range from 1220mm from the subtending leaf to the apex; and bear 39 flowers in a lax spike. Flowers are unisexual or rarely hermaphrodite, and cream-green in colour. Plants are also mostly unisexual (Makinson and Mallinson 1997).
M. tuggeranong was described from a single female plant and six male plants discovered in the Murrumbidgee River Corridor (MRC) near Tuggeranong in 1997. In May 1999, an additional male plant was discovered in the MRC a short distance from the other seven plants. Although extensive searches have been undertaken (R.Makinson pers. comm.), this population appears to be the only one in existence.
M. tuggeranong is similar in many respects to M. that occurs at higher altitudes (680 1200in the ACT, NSW Southern Highlands, Victoria, Tasmania and New Zealand (Makinson and Mallinson 1997). The nearest known occurrences of M. to the M. site are about 25east-south-east in the Googong Reservoir area (altitude c.and 35km to the west-north-west in the upper Cotter River valley (altitude c.(Makinson and Mallinson 1997).
Figure 1: Muehlenbeckia tuggeranong. Top left - flowers and leaves; top right - stems and leaves; bottom left - detail of female flower; bottom right - detail of male flower.
The known habitat of the species is restricted to flood terraces, altitude c.m, on the eastern bank of the Murrumbidgee River near Tuggeranong in the ACT, in areas of rocky outcrops with pockets of silty sandy soil (Makinson and Mallinson 1997).
M. is found in a highly disturbed riparian shrubby woodland association, heavily invaded by exotic weeds. The tree layer is largely remnant. The species is found on almost bare rock, or tangled amongst other vegetation (D.pers. comm.).
Associated native species include River Oak Casuarina cunninghamiana; Burgan Kunzea ericoides; Silver Wattle Acacia dealbata; Grevillea juniperina; Purple Loosestrife Lythrum salicaria; Narrow-leaved Cumbungi Typha domingensis; a sedge Isolepis sp.; Tussock Grass Poa labillardieri and Common Reed Phragmites australis. There is also a range of introduced species including White Willow Salix alba; Sweetbriar Rosa rubiginosa; Great Mullein Verbascum thapsus; Oenothera sp.; Vipers Bugloss Echium vulgare; Fennel Foeniculum vulgare; Lambs Tongue Plantago lanceolata; Curled Dock Rumex crispus; St Johns Wort Hypericum perforatum; Umbrella Sedge Cyperus eragrostis; Toowoomba Canary Grass Phalaris aquatica; African Lovegrass Eragrostis curvula and Yorkshire Fog Holcus lanatus (D.pers. comm.).
Figure 2: Map showing location (¦) of M.. Hatched area represents the Murrumbidgee and Molonglo River corridors.