Stenanthemum divaricatum

Stenanthemum divaricatum is a species of flowering plant in the family Rhamnaceae and is endemic to the southwest of Western Australia. It is a small, often spiny shrub with sparsely hairy young stems, fan-shaped to narrowly egg-shaped leaves and densely, softly-hairy heads of tube-shaped flowers.

Stenanthemum divaricatum

Priority Three — Poorly Known Taxa (DEC)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Rosales
Family: Rhamnaceae
Genus: Stenanthemum
Species:
S. divaricatum
Binomial name
Stenanthemum divaricatum

Description

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Stenanthemum divaricatum is an often spiny shrub that typically grows to a height of up to 20 cm (7.9 in) and has many branches, its young stems sparsely covered with soft, greyish hairs. Its leaves are fan-shaped to narrowly egg-shaped with the narrower end towards the base, mostly 3–8 mm (0.12–0.31 in) long and 1.5–4 mm (0.059–0.157 in) wide on a petiole 0.3–1 mm (0.012–0.039 in) long, with broadly triangular to rectangular stipules 0.8–1.2 mm (0.031–0.047 in) long and joined together at the base. The upper surface of the leaves is glabrous and the lower surface is covered with soft, greyish hairs. The flowers are moderately to densely covered with soft, greyish hairs. The floral tube is 0.1–0.2 mm (0.0039–0.0079 in) long and 0.7–0.9 mm (0.028–0.035 in) wide, the sepals 0.7–1.0 mm (0.028–0.039 in) long and the petals 0.5–0.6 mm (0.020–0.024 in) long. Flowering occurs in August and September, and the fruit is about 2 mm (0.079 in) long.[2][3]

Taxonomy and naming

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This species was first formally described in 1863 by George Bentham who gave it the name Spyridium divaricatum in Flora Australiensis from specimens collected by Augustus Oldfield.[4][5] In 1995, Barbara Lynette Rye changed the name to Stenanthemum divaricatum in the journal Nuytsia.[6] The specific epithet (divaricatum) means "widely-spreading" or "forked".[7]

Distribution and habitat

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Stenanthemum divaricatum grows in shrubland on sand near Shark Bay in the Carnarvon, Geraldton Sandplains and Yalgoo bioregions of south-western Western Australia.[2][8][3]

Conservation status

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Stenanthemum divaricatum is listed as "Priority Three" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions,[8] meaning that it is poorly known and known from only a few locations but is not under imminent threat.[9]

References

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  1. ^ "Stenanthemum divaricatum". Australian Plant Census. Retrieved 25 December 2022.
  2. ^ a b Kellerman, Jurgen; Thiele, Kevin R. Kodela, Phillip G. (ed.). "Stenanthemum divaricatum". Australian Biological Resources Study, Department of Agriculture, Water and the Environment: Canberra. Retrieved 25 December 2022.
  3. ^ a b Kellermann, Jürgen; Thiele, Kevin R. (2021). "The other 'propeller plant' – Notes on Stenanthemum Reissek (Rhamnaceae: Pomaderreae) and a key to the genus in Australia" (PDF). Swainsona. 35: 15–16. Retrieved 3 January 2023.
  4. ^ "Spyridium divaricatum". APNI. Retrieved 25 December 2022.
  5. ^ Bentham, George; von Mueller, Ferdinand (1863). Flora Australiensis. Vol. 1. London: Lovell Reeve & Co. p. 427. Retrieved 25 December 2022.
  6. ^ "Stenanthemum divaricatum". APNI. Retrieved 25 December 2022.
  7. ^ Sharr, Francis Aubi; George, Alex (2019). Western Australian Plant Names and Their Meanings (3rd ed.). Kardinya, WA: Four Gables Press. p. 167. ISBN 9780958034180.
  8. ^ a b "Stenanthemum divaricatum". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  9. ^ "Conservation codes for Western Australian Flora and Fauna" (PDF). Government of Western Australia Department of Parks and Wildlife. Retrieved 25 December 2022.