National recovery plan for Ginninderra Peppercress (Lepidium ginninderrense)

A Recovery Plan under the Environment Protection and Biodiversity Conservation Act 1999 (C’wlth), based on an Action Plan (Action Plan No. 25) prepared for the species under the Nature Conservation Act 1980 (ACT)

Species Description and Ecology

Description

The Ginninderra Peppercress Lepidium ginninderrense N. H. Scarlett (Figure 1) is a perennial herb to a maximum height of about 20 cm, with one to six branched stems arising from a rootstock. Stems are striate and moderately papillose. Leaves are thick and fleshy, glabrous and shiny on the upper surface. Rosette leaves are widely spaced and very narrow (1.5 to 2.0 mm wide) and 15-55 mm long. The inflorescence is an elongating raceme with a maximum length of 15 cm. Flowers are small, 2 mm wide and 1.5 mm long. Sepals are less than 1 mm long and about 0.5 mm wide, green and with scarious margins. Petals are absent (Scarlett 2001). Lepidium ginninderrense flowers in late spring. It sets seed mainly in December and the majority of seed is dispersed before August (Avis 2000).

Distribution and Abundance

The only known population of Lepidium ginninderrense occurs in the north-west corner of Belconnen Naval Transmission Station in the suburb of Lawson in the Australian Capital Territory (which is the type locality). The population is currently about 2000 plants, occupying an area of 90 x 30 metres (Avis 2000).

A second record of L. ginninderrense is from 1952 in the ACT suburb of Reid, however, a recent search failed to locate the species in this area (M. Gray pers. comm. cited in Scarlett 2001).

L. ginninderrense has been recorded only from these two cited localities in the ACT and is not known from outside the ACT. The species is remarkably disjunct from all other members of the allied Lepidium section Papillosa in south-eastern Australia, which are mainly confined to the inland plains west and north of the Eastern Highlands (Scarlett 2001).

Habitat

At the type locality Lepidium ginninderrense grows on the flood plain of Ginninderra Creek, in Natural Temperate Grassland dominated by Austrodanthonia spp. and Bothriochloa macra. Associated herbaceous species include Plantago gaudichaudii, Juncus filicaulis, Triptilodiscus pygmaeus, Parentucellia latifolia and Calocephalus citreus (Scarlett 2001).

Avis (2000) has shown that L. ginninderrense grows in areas with relatively low perennial grass cover, often with indications of past soil disturbance.

The soil type over most of the site is a shallow red earth, with patches of colluvium on the footslopes (Crawford and Rowell 1995a cited in Lowe 1996, p. 41). The population occurs at an altitude of approximately 580 metres.

 Click for a map showing the location of the Ginninderra Peppercress (Lepidium ginninderrense)

A map showing the location of the Ginninderra Peppercress (Lepidium ginninderrense) is at Figure 2.