''Leptospermum exsertum'' is a small, sparsely branched shrub that 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 els ...

to Western Australia. It has thick, wedge-shaped to heart-shaped leaves with the narrower end towards the base, often with a sharply pointed tip, white flowers arranged singly or in groups of up to three and fruit that falls off when mature.

Description

''Leptospermum exsertum'' is a shrub that typically grows to a height of and has thin, firm bark on the older stems, and

glabrous Glabrousness (from the Latin '' glaber'' meaning "bald", "hairless", "shaved", "smooth") 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 o ...

younger stems. The leaves are wedge-shaped to heart-shaped with the narrower end towards the base, mostly long and wide, often with a sharply pointed tip. The flowers are borne singly or in groups of up to three and are wide. There are reddish bracts and

bracteoles In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

at the base of the flower, the bracteoles falling off as the flower opens. The

floral cup In angiosperms, a hypanthium or floral cup is a structure where basal portions of the calyx, the corolla, and the stamens form a cup-shaped tube. It is sometimes called a floral tube, a term that is also used for corolla tube and calyx tube. It of ...

is about 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 The term ''sepalum'' was coined ...

s triangular long and the

petal Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usuall ...

s about long. The

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

s are in bundles of about five and are long. Flowering occurs from August to September and the fruit is about in diameter with the remains of the sepals attached and the valves projecting upwards.

Taxonomy and naming

''Leptospermum exsertum'' was first formally described in 1989 by Joy Thompson in the journal '' Telopea'', based on plant material collected by

John Stanley Beard John Stanley Beard (15 February 1916 – 17 February 2011) was a British-born forester and ecologist who resided in Australia. Beard studied at the University of Oxford where he completed his doctoral thesis on tropical forestry. While worki ...

near

Tardun Tardun is a small town in the Mid West region of Western Australia. The townsite is located along the Mullewa to Wongan Hills railway line. The location of the town was decided in 1913 when the route of the railway was being planned. The name ...

in 1973. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''exsertum'') is a Latin word meaning "protruding", refers to the valves of the fruit.

Distribution and habitat

This tea-tree is found on sand plains and sandy heath in the north-west corner of the

Avon Wheatbelt The Avon Wheatbelt is a bioregion in Western Australia. It has an area of . It is considered part of the larger Southwest Australia savanna ecoregion. Geography The Avon Wheatbelt bioregion is mostly a gently undulating landscape with low reli ...

biogeographic region An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas o ...

Conservation status

This species is classified as "

Priority One Prioritization is an action that arranges items or activities in order of importance. Priority may refer specifically to: Law * Priority or right of way on the road, see Traffic § Priority (right of way) ** Priority signs, a traffic sign tha ...

" by the Government of Western Australia

Department of Parks and Wildlife The Department of Parks and Wildlife (DPaW) was the department of the Government of Western Australia responsible for managing lands described in the ''Conservation and Land Management Act 1984'' and implementing the state's conservation and en ...

, meaning that it is known from only one or a few locations which are potentially at risk.

References

{{Taxonbar, from=Q15368275 exsertum Flora of Western Australia Plants described in 1989 Taxa named by Joy Thompson