''Fontainea borealis'' is a small tree endemic to

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

, in the family,

Euphorbiaceae Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, e ...

, which grows to a height of 12 m.

Description

''Fontainea borealis'' is a small

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 ...

tree growing to 12 m. The colour of the stem exudate is unknown. New shoots have dense, antrorse (upward pointing) golden

trichomes Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

. There are no

stipules In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

and the leaves have petioles, which are swollen at both the base and apex. The upper surfaces of the leaves are dark-green and the lower surfaces, pale-green. There are 8-14 lateral veins on each side of the midrib and between these the venation is

reticulate Reticulation is a net-like pattern, arrangement, or structure. Reticulation or Reticulated may refer to: * Reticulation (single-access key), a structure of an identification tree, where there are several possible routes to a correct identificatio ...

. This plant is very like ''

Fontainea picrosperma ''Fontainea picrosperma'', commonly known as the blushwood tree, is a rainforest tree in the family Euphorbiaceae endemic to Queensland in Australia, where it grows on the Atherton Tablelands. Uses An anti-cancer drug known as EBC-46 has been ...

'', but differs in that it has no glands in the leaf lamina; the disk is irregularly lobed and not as high as that of '' F. picrosperma'' (c 0.6 mm high vs 0.7-1 mm); the calyx of the male flower has four lobes (versus 2-3 lobes); the male calyx lobes are ovate/broadly ovate versus triangular ovate; and the stamens are joined for 1–1.5 mm versus 0.5 mm for '' F. picrosperma''..

Distribution and habitat

''Fontainea borealis'' is known only from the

Eastern Highlands Province Eastern Highlands is a highlands province of Papua New Guinea. The provincial capital is Goroka. The province covers an area of 11,157 km², and has a population of 579,825 (2011 census). The province shares a common administrative boundary w ...

of Papua New Guinea, at altitudes of 1800-2000 m.

Taxonomy and naming

The plant was first described by

Paul Irwin Forster Paul Irwin Forster (born 1961) is an Australian botanist. He obtained his doctorate from the University of Queensland in 2004 with his thesis ''The pursuit of plants : studies on the systematics, ecology and chemistry of the vascular flora of A ...

in "Three new species of ''Fontainea'' Heckel (Euphorbiaceae) from Australia and Papua New Guinea". The holotyp
K000959476
was collected in 1944 by L.S. Smith at

Aiyura Aiyura is the name of a valley located in the Eastern Highlands of Papua New Guinea. It is the home of the Aiyura Agricultural Research Station, which was operated originally as the "Highlands Agricultural Experiment Station, Aiyura" begun in 193 ...

in the Central Highlands of

. Holotype of ''Fontainea borealis'' P.I.Forst. family EUPHORBIACEAE)
JSTOR Global Plants. Retrieved 25 April 2019. The specific epithet, ''borealis'', derives from the Latin for "northern" and refers to the northerly distribution of this species with respect to the genus.

References

australis Flora of Papua New Guinea Taxa named by Paul Irwin Forster Plants described in 1997 {{Euphorbiaceae-stub