''Dacrydium guillauminii'', commonly known as cat-tail Rimu or swamp Dacrydium, is a species of

conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

in the family

Podocarpaceae Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs.James E. Eckenwalder. 2009. ''Conifers of the World''. Portland, Oregon: Timber Pre ...

. It is found only in

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

. It is a slow growing shrub or small tree with roots that grow in water, and reaches a height between 1 and 2 metres. The species occurs on the banks of rivers and lakes in the south of Grand Terre, the largest island of New Caledonia. It is threatened by wildfires and

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. Its name honors the French botanist

André Guillaumin André Louis Joseph Edmond Armand Guillaumin (21 June 1885 in Arrou – 29 May 1974 in Athis-Mons) was a French Botany, botanist. He obtained his License#Academy, license in biology in 1906 and began work in the ''Muséum national d'histoire ...

, who spearheaded the study of the flora of New Caledonia.

Description

''Dacrydium guillauminii'' is a shrub that grows to a height of around which forms an erect, densely branched bush. The bark is brown and fibrous, covered with small scales and lenticels when young, and developing many small cracks and crevices as it grows older. The leaves are needle-like with sharp points, overlapping and slightly compressed, and long. The male

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

may be apical or axillary, the latter being considerably smaller than the terminal ones, which can be long. The female cones grow at the tips of the twigs or sometimes on short lateral twigs, and may each contain up to five seeds.

Distribution and habitat

''Dacrydium guillauminii'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

where it occurs in the southeast of the country. Its range is restricted to a small area around Rivière des Lacs, Lac en Huit, Lac Intermédaire and Grand Lacs, where it grows on the margins of streams and lakes. Its total area of occupation is about , and there are thought to be fewer than one hundred mature plants.

Status

In its habitat beside watercourses, this shrub often grows in association with ''

Retrophyllum minus ''Retrophyllum minus'', the ''bois bouchon'', is a species of conifer in the family Podocarpaceae. It is endemic to New Caledonia. It is a sparsely branched small tree with a flared trunk which tapers towards the top and has rough bark. It pr ...

'' and ''

Callitris pancheri ''Callitris pancheri'' is a plant species of the family Cupressaceae. It is endemic to New Caledonia, where it occurs in small, scattered population along rivers. It used to be placed in its own genus ''Neocallitropsis'' but molecular phylogene ...

'', two other endangered

s endemic to New Caledonia, and it sometimes hybridises with ''

Dacrydium araucarioides ''Dacrydium araucarioides'' is a species of conifer in the family Podocarpaceae. It is found only in New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Loca ...

''. The area where they live is prone to wildfires, which kill the shrubs and trees, and part of the area has been inundated as a result of the filling of a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

. With its habitat being degraded and the number of mature plants in decline, the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed the conservation status of ''Dacrydium guillauminii'' as being " critically endangered".

References

{{Taxonbar, from=Q5207753 guillauminii Critically endangered plants Endemic flora of New Caledonia Taxonomy articles created by Polbot