Muehlenbeckia florulenta, commonly known as Tangled Lignum or often simply Lignum, is a plant native to inland Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. It is associated with wetland habitats, especially those in arid and semiarid regions subject to cycles of intermittent flooding and drying out. The Wiradjuri

Wiradjuri language

Wiradjuri is a Pama–Nyungan language of the Wiradhuric subgroup. It was the traditional language of the Wiradjuri people of Australia, but is no longer in general use. The process of reclaiming the language was greatly assisted by the publication in 2005 of A First Wiradjuri Dictionary by elder...

 name for the plant is Gweeargal.

Description

Lignum is a perennial, monoecious shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

, 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

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are 15–70 mm long and 2–10 mm wide. The grey-green stems often end in a sharp point. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s 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.

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

Salinity

Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...

 and drought

Drought

A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...

 and may be used as an indicator of dryland soil salinity

Salinity in Australia

Soil salinity and dryland salinity are two problems degrading the environment of Australia. Salinity is a concern in most states, but especially in the south-west of Western Australia....

. 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, fox

Red Fox

The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...

es and rabbit

European Rabbit

The European Rabbit or Common Rabbit is a species of rabbit native to south west Europe and north west Africa . It has been widely introduced elsewhere often with devastating effects on local biodiversity...

s.

Distribution and habitat

Lignum occurs in all of Australia’s mainland states, as well as the Northern Territory. The plant’s preferred habitats include floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

s, swamp

Swamp

A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...

s, gilgai

Gilgai

Gilgai is an Australian English word referring to a small, ephemeral lake formed from a depression in the soil surface. Gilgais are commonly a few metres across and less than 30 cm deep, however in some instances they may be several metres deep and up to 100 metres across. Gilgais are common...

s and other intermittently flooded areas. In southern Australia it is often associated with stands of River Red Gum and Black Box

Eucalyptus largiflorens

Eucalyptus largiflorens, or Black Box, is a species of Eucalyptus which is endemic to Australia. It is a tree grows up to 20 metres in height...

.