Jacksonia effusa is a species of flowering plant in the family Fabaceae and is endemic to a restricted area near Nitmiluk (Katherine) Gorge. It is a sprawling shrub, its end branches sharply-pointed phylloclades, its leaves reduced to sharply-pointed, narrowly egg-shaped scales, its flowers pale yellow, and its fruit, woody, hairy pods.
Jacksonia effusa is a sprawling shrub, that typically grows up to high and wide, its branches greyish-green or light green. Its end branches are sharply-pointed phylloclades, with its leaves reduced to sharply-pointed, narrowly egg-shaped, reddish-brown scales, long and wide. The flowers are sparsely arranged along the branches, each flower on a pedicel long. There are narrowly lance-shaped bracteoles long and wide at the base of the floral tube. The floral tube is about long and the sepals are membranous, the lower lobes long and wide, the upper lobes longer and narrower. The flowers are pale yellow, the standard petal is long and deep, the wings long, and the keel long. The stamens have pink filaments long. Flowering occurs in March, and the fruit is a woody, hairy, oval pod, long and wide.[1]
Jacksonia effusa was first formally described in 2007 by Jennifer Anne Chappill in Australian Systematic Botany from specimens collected south-east of the Kakadu Highway in 1990.[2] The specific epithet (effusa) means 'spread out', or 'straggling'.[3]
This species of Jacksonia is only known from near Katherine Gorge, Bloomfield Springs and Eva Valley, where it grows in sand in woodland in Kakadu and Nitmiluk National Parks.[4]
Jacksonia effusa is listed as of "least concern" under the Northern Territory Government Territory Parks and Wildlife Conservation Act.