Lignum is a
perennial,
dioecious shrub, growing to 2.5 m in height, with its multitude of thin, intertwined and tangled branches and branchlets forming dense thickets to the exclusion of other species. Its thin, narrow
leaves are 15–70 mm long and 2–10 mm wide. The grey-green stems often end in a sharp point. The
flowers are small and cream to yellowish, solitary or clustered along the branchlets and occurring through most of the year. The fruit is top-shaped, dry, and about 5 mm long. File:Lignum foliage.jpg|Foliage File:Lignum blooms.jpg|Male Flowers Muehlenbeckia florulenta DSC 1381.jpg|habitat,
Macquarie Marshes File:Duma florulentaPB161960.jpg|At most south-eastern edge of its distribution, north east of
West Wyalong Muehlenbeckia Lignum swamp.jpg|Lignum swamp,
Narran Lake nature reserve Lignum often appears leafless as the leaves are produced on younger growth but soon die off, especially in dry conditions. New leaves and shoots are rapidly produced in response to rainfall or flooding. The plant has a very deep root system, penetrating the soil to at least 3 m in depth. It is highly tolerant of
salinity and
drought and may be used as an indicator of
dryland soil salinity. Because of its densely tangled growth habit, it provides protected breeding habitat for native wildlife such as
waterbirds, though it can also provide refuge for pest species such as
feral pigs,
foxes and
rabbits. ==Taxonomy==