''Allocasuarina defungens'', commonly known as dwarf heath casuarina, is a species of flowering plant in the family

Casuarinaceae The Casuarinaceae are a family of dicotyledonous flowering plants placed in the order Fagales, consisting of four genera and 91 species of trees and shrubs native to eastern Africa, Australia, Southeast Asia, Malesia, Papuasia, and the Pacifi ...

and is endemic to a restricted area of New South Wales. It is a straggly,

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

shrub that has branchlets up to long, the leaves reduced to scales in whorls of five to seven, the fruiting cones long containing winged seeds (samaras) about long.

Description

''Allocasuarina defungens'' is a straggly, more or less erect, dioecious or monoecious shrub that forms a lignotuber, and typically grows to a height of . Its branchlets are more or less erect, up to long, the leaves reduced to erect, scale-like teeth long, arranged in whorls of five to seven around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are long and wide. Male flowers are arranged in head-like spikes long, the

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

long. Female cones are cylindrical, on a peduncle long. Mature cones are long and in diameter, the samaras about long.

Taxonomy

''Allocasuarina defungens'' was first formally described in 1989 by Lawrie Johnson in the '' Flora of Australia'' from specimens collected b
Bob Coveny
near

Nabiac Nabiac is a small town on the Mid North Coast, New South Wales, Australia in Mid-Coast Council. It is north-west of Forster, New South Wales, Forster, and south of Taree, New South Wales, Taree. At the , the population of Nabiac was 1,294. Nabia ...

airstrip in 1967. The specific epithet, (''defungens'') means "to finish" or "to die", referring the species' lack of vigour and "probable impending extinction".

Distribution and habitat

Dwarf heath casuarina mainly grows in tall heath in coastal areas between

Raymond Terrace Raymond Terrace is a town in the Hunter Region of New South Wales, Australia, about by road north of Newcastle on the Pacific Highway. Established in 1837 it is situated at the confluence of the Hunter and Williams rivers. The town was named ...

and Byron Bay in eastern New South Wales.

Conservation status

''Allocasuarina defungens'' is listed as "endangered" under the Australian Government '' Environment Protection and Biodiversity Conservation Act 1999'' and the new South Wales Government '' Biodiversity Conservation Act 2016''. The main threats to the species are habitat disturbance caused by mining and housing development, and by inappropriate fire regimes.

References

{{Taxonbar, from=Q15376318 defungens Fagales of Australia Flora of New South Wales Plants described in 1989 Taxa named by Lawrence Alexander Sidney Johnson