Apectospermum exsertum

Apectospermum exsertum

Priority One — Poorly Known Taxa (DEC)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Myrtales
Family: Myrtaceae
Genus: Apectospermum
Species:
A. exsertum
Binomial name
Apectospermum exsertum
Occurrence data from AVH

Apectospermum exsertum is a small, sparsely branched shrub that is endemic 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

Apectospermum exsertum is a shrub that typically grows to a height of 0.3–0.6 m (1 ft 0 in – 2 ft 0 in) and has thin, firm bark on the older stems, and glabrous younger stems. The leaves are wedge-shaped to heart-shaped with the narrower end towards the base, mostly 3–5 mm (0.12–0.20 in) long and 2–3 mm (0.079–0.118 in) wide, often with a sharply pointed tip. The flowers are borne singly or in groups of up to three and are 5–8 mm (0.20–0.31 in) wide. There are reddish bracts and bracteoles at the base of the flower, the bracteoles falling off as the flower opens. The floral cup is about 2 mm (0.079 in) long, the sepals triangular 1.5–2 mm (0.059–0.079 in) long and the petals about 3 mm (0.12 in) long. The stamens are in bundles of about five and are 1.6 mm (0.063 in) long. Flowering occurs from August to September and the fruit is about 3 mm (0.12 in) in diameter with the remains of the sepals attached and the valves projecting upwards.[2][3]

Taxonomy and naming

This species was first formally described in 1989 by Joy Thompson as Leptospermum exsertum in the journal Telopea, based on plant material collected by John Stanley Beard near Tardun in 1973.[2][4] In 2023, Peter Gordon Wilson transferred the species to the genus Apectospermum as A. exsertum in the journal Taxon.[1][5] The specific epithet (exsertum) is a Latin word meaning "protruding", refers to the valves of the fruit.[2][6]

Distribution and habitat

This tea-tree is found on sand plains and sandy heath in the north-west corner of the Avon Wheatbelt biogeographic region.[2][3]

Conservation status

This species is classified as "Priority One" by the Government of Western Australia Department of Parks and Wildlife,[3] meaning that it is known from only one or a few locations which are potentially at risk.[7]

References

  1. ^ a b "Apectospermum exsertum". Plants of the World Online. Retrieved 15 August 2024.
  2. ^ a b c d Thompson, Joy (1989). "A revision of the genus Leptospermum (Myrtaceae)". Telopea. 3 (3): 352–353.
  3. ^ a b c "Apectospermum exsertum". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  4. ^ "Leptospermum exsertum". APNI. Retrieved 30 March 2020.
  5. ^ Wilson, Peter G.; Heslewood, Margaret M. (2023). "Revised taxonomy of the tribe Leptospermeae (Myrtaceae) based on morphological and DNA data". Taxon. 72 (3): 550–571. doi:10.1002/tax.12892. Retrieved 28 July 2024.
  6. ^ Francis Aubie Sharr (2019). Western Australian Plant Names and their Meanings. Kardinya, Western Australia: Four Gables Press. p. 195. ISBN 9780958034180.
  7. ^ "Conservation codes for Western Australian Flora and Fauna" (PDF). Government of Western Australia Biodiversity, Conservation and Attractions. Retrieved 17 August 2024.