''Bosistoa transversa'', commonly known as yellow satinheart, or three-leaved bosistoa, is a species of small to medium-sized rainforest tree that is

endemic Endemism is the state of a species being found only 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 foun ...

to eastern Australia. It has mostly

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and ...

leaves, usually with three leaflets, and

panicle In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...

s of small white flowers.

Description

''Bosistoa transversa'' is a tree that typically grows to a height of and has a cylindrical, sometimes crooked trunk. The trunk has a diameter of and has mostly smooth dark brown bark with irregular horizontal ridges. The leaves are arranged in opposite pairs on thin brown or grey-brown branches and are pinnate, long on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

long. The leaves usually have three, sometimes up to seven glossy leaflets with prominent oil glands. The leaflets are oblong to elliptical, long and wide, the side leaflets on petiolules long, the end leaflet on a petiolule long. Appearing from January to March, the tiny white flowers are arranged in panicles long, on the ends of branches or in upper leaf

axil A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

s. The five

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s are about long the five

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s broadly elliptical and about long. Flowering occurs from December to May and is followed by pairs of small woody, oval follicles that ripen from May to July.

Taxonomy

Yellow satinheart was first formally described in 1917 by

John Frederick Bailey John Frederick Bailey (5 August 1866 – 19 May 1938) was a botanist and horticulturist active in Australia in the late 19th and early 20th century. Bailey became Director of the Botanic Gardens of Brisbane in 1905. He succeeded his father, Fr ...

and

Cyril Tenison White Cyril Tenison White (17 August 1890 – 15 August 1950) was an Australian botanist. Early life White was born in Brisbane, Queensland, to Henry White, a trade broker, and Louisa (''nee'' Bailey). He attended school at South Brisbane State Sch ...

and the description was published in the ''Botany Bulletin'' of the Department of Agriculture, Queensland. The generic name ''Bosistoa'' honours the name of

Joseph Bosisto Joseph Bosisto CMG, MLA JP (21 March 1827 – 8 November 1898), was a chemist and politician in colonial Victoria, Australia. Background Bosisto was the son of William Bosisto and Maria (née Lazenby), of Cookham, Berkshire, and was born on 2 ...

, a manufacturer of essential oils. The specific epithet ''transversa'' refers to the transversal ribbed

carpel Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more ...

s of the fruit.

Distribution and habitat

''Bosistoa transversa'' occurs from Mount Larcom in central-eastern

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, south to

Mullumbimby file:BigThingsMullumbimby.jpg, Welcome sign in Mullumbimby Mullumbimby, locally nicknamed Mullum, is a town in the Byron Shire in the Northern Rivers region of New South Wales, Australia. It promotes itself as "The Biggest Little Town in Austra ...

in north eastern

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. It is found in forest and subtropical rainforest from sea level to an altitude of .

Conservation status

The yellow satinheart is classified as ''vulnerable'' under the Australian Government ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cult ...

'' and in New South Wales under the '' Biodiversity Conservation Act 2016''. The main threats to the species include clearing of rainforests, invasion of remaining rainforest areas by weeds, and grazing by livestock.

References

{{Taxonbar, from=Q4947283 transversa Sapindales of Australia Flora of New South Wales Flora of Queensland Plants described in 1917 Taxa named by Frederick Manson Bailey Taxa named by Cyril Tenison White