''Ricinocarpos linearifolius'' is a species of flowering plant in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 Euphorbia, the type genus of the family. Most spurges, such as ''Euphorbia paralias'', ar ...

and 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 is a

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 comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

shrub with hairy young branchlets, linear leaves and white flowers, arranged either singly, with two to four male flowers, or a single female flower surrounded by up to three male flowers.

Description

''Ricinocarpos linearifolius'' is a monoecious or dioecious shrub that typically grows to a height of up to , its young branchlets densely covered with greyish-white, star-shaped hairs. The leaves are linear, long and wide on a densely hairy

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 upper surface of the leaves quickly becomes

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

and the lower surface is densely covered with silky hairs, so that only the midrib is visible. The flowers are arranged either as a single male or female flower, or as clusters of two to four male flowers, or with a single female flower surrounded by up to three male flowers. Male flowers are on a slender, densely hairy

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

long, the

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 joined at the base and densely hairy, the sepal lobes egg-shaped, long. The petals are white and egg-shaped with the narrower end towards the base to round, long and wide. Each male flower has 40 to 50

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s. Female flowers are on a stout, hairy pedicel long, the sepal lobes egg-shaped, long and wide. The petals are white and egg-shaped with the narrower end towards the base, and long with smooth edges. Flowering occurs throughout the year with a peak from August to October, and the fruit is a more or less spherical capsule in diameter and covered with star-shaped hairs.

Taxonomy and naming

''Ricinocarpos linearifolius'' was first formally described in 2007 by David Halford and Rodney Henderson in the journal '' Austrobaileya'' from specimens collected by Henderson in the northern end of the

Blackdown Tableland National Park Blackdown Tableland is a national park in the Central Highlands Region, Queensland, Australia. Geography The park is in Central Queensland, northwest of Brisbane. The mountainous terrain of the tablelands provides a unique landscape featuring ...

in 1987. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''linearifolius'') means "linear-leaved".

Distribution and habitat

This species grows in heath, woodland and open forest between

Jericho Jericho ( ; , ) is a city in the West Bank, Palestine, and the capital of the Jericho Governorate. Jericho is located in the Jordan Valley, with the Jordan River to the east and Jerusalem to the west. It had a population of 20,907 in 2017. F ...

Biggenden Biggenden is a rural town and Suburbs and localities (Australia), locality in the North Burnett Region, Queensland, Australia. In the , the locality of Biggenden had a population of 788 people. Geography Biggenden is on the Isis Highway north ...

and Inglewood in Queensland, and near

Warialda Warialda is a town in the North West Slopes region of New South Wales, Australia, in Gwydir Shire. It is situated on the banks of Warialda Creek. At the , Warialda had a population of 1,120. Transport The Gwydir Highway runs through town and ...

in New South Wales.

References

{{Taxonbar, from=Q15374952 linearifolius Malpighiales of Australia Flora of Queensland Plants described in 2007 Taxa named by Rodney John Francis Henderson