''Oreobolus pumilio'', commonly known as alpine tuftrush or Ibrang`rank, is a small mat forming herb which is distributed throughout the Australasian region. It is a relative of the

sedge The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' wit ...

. It is often found in

cushion plant A cushion plant is a compact, low-growing, mat-forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world. The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in ...

communities, in alpine environments, where it is a dominant species. As a

, it is an ecological engineer and enables other species to grow in the alpine herblands to which it is native to.

Taxonomy

''Oreobolus pumilio'' is a member of the

Cyperaceae The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' w ...

(sedge) family which is one of the main families of monocots. There are two subspecies of ''Oreobolus pumilio,'' the subspecies ''Oreobolus pumilio var. pumilio'' (alpine Tuft rush) which is endemic to southeast

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, while the subspecies ''Oreobolus pumilio var. clemensiae'' is endemic to

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

Distribution and habitat

''Oreobolus pumilio'' is native to New Guinea and the southeast of the Australian continent. In these regions it is distributed in alpine habitats which lie between 900-2400 metres in altitude. This species is characteristic of several alpine habitat types such as montane button grass and is an

indicator species A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

of alpine short herbfields. MyMap

Morphology

''Oreobolus pumilio'' is mat forming herb growing to 8 cm high with blade like leaves. Leaf colouration varies between a verdant green and a reddy-brown. As ''Oreobolus pumilio'' grows in high alpine environments its short growth, like that of all cushion plants, is advantageous. This is because the environments, that they grow in, tend to have strong winds which may damage any leaves growing above the thin layer of still air that covers the ground. Cushion plant community on mount field 8-2-22

Cushion plant community on mount field 8-2-22

Ecology

''Oreobolus pumilio'' is one of the species in a cushion plant community. These communities are considered ecological engineers as they can have an effect on the environment such as the ability to produce a peat like soil. Also, these communities are known to enable some other species to live in environments which they would not usually be able to inhabit as they can increase water and nutrient availability.

Conservation status

One subspecies, ''Oreobolus pumilio var pumilio'', of ''Oreobolus pumilio'' is considered rare in

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

References

{{Taxonbar, from=Q15550751 pumilio Taxa named by Robert Brown (botanist, born 1773)