Thryptomene australis

From Wikipedia, the free encyclopedia

Hook-leaf thryptomene
Thryptomene australis subsp. australis - Flickr - Kevin Thiele.jpg
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Myrtales
Family: Myrtaceae
Genus: Thryptomene
Species:
T. australis
Binomial name
Thryptomene australis
Endl.[1]

Thryptomene australis, commonly known as hook-leaf thryptomene,[2] is a species of flowering plant in the family Myrtaceae and is endemic to the south-west of Western Australia. It is an erect, bushy and spreading shrub with upward-pointing leaves with the tip curving outwards, and flowers with white petals arranged spike-like near the ends of the branchlets.

Description[]

Thryptomene australis is an erect, bushy and spreading shrub that typically grows to a height of 0.8–3.5 m (2 ft 7 in – 11 ft 6 in) with upwards-pointing leaves with the tip curving outwards. The leaves are linear to narrow egg-shaped with the narrower end towards the base, 4–7 mm (0.16–0.28 in) long and 0.5–1.2 mm (0.020–0.047 in) wide on a petiole 0.7–1 mm (0.028–0.039 in) long. The flowers are arranged in pairs in up to eleven leaf axils near the end of branchlets. The flowers are 6–7 mm (0.24–0.28 in) diameter with egg-shaped to broadly elliptic white or pale pink sepals about 1.4 mm (0.055 in) long and 1.6–2.0 mm (0.063–0.079 in) wide. The petals are white, broadly egg-shaped, 2.0–2.4 mm (0.079–0.094 in) long, and there are seven to ten stamens. Flowering mainly occurs between July and November and the fruit is a nut about 2.5 mm (0.098 in) long and wide.[2][3][4]

Taxonomy[]

Thryptomene australis was first formally described in 1838 by Stephan Ladislaus Endlicher in Stirpium Australasicarum Herbarii Hugeliani Decades Tres, published in the journal Annalen des Wiener Museums der Naturgeschichte and was the first species of Thryptomene described.[5][6] The specific epithet (australis) means "southern".[7]

In 2001, Barbara Lynette Rye and Malcolm Eric Trudgen described two subspecies in the journal Nuytsia and the names are accepted by the Australian Plant Census:

  • Thryptomene australis Endl. subsp. australis[8] has eight to twelve stamens on filaments usually longer than 0.8 mm (0.031 in);[3]
  • Thryptomene australis subsp. brachyandra Rye & Trudgen[9] has seven to ten stamens on filaments usually shorter than 0.6 mm (0.024 in).[3]

Distribution and habitat[]

Both subspecies of hook-leaf thryptomene are widely distributed in the south-west of Western Australia where they mainly grow on granite outcrops but also on plains, around salt lakes and creeklines and in firebreaks in gravelly, sandy, clay or loamy soils. The species occurs in the Avon Wheatbelt, Esperance Plains, Mallee and Coolgardie biogeographic regions but subsp. australis is mostly absent from the last of these.[10][11][3]

Conservation status[]

Both subspecies of Thryptomene australis are list as "not threatened" by the Western Australian Government Department of Parks and Wildlife.[10][11]

References[]

  1. ^ "Thryptomene australis". Australian Plant Census. Retrieved 23 April 2021.
  2. ^ a b "Thryptomene australis". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  3. ^ a b c d Rye, Barbara L.; Trudgen, Malcolm E. (2001). "A taxonomic revision of Thryptomene section Thryptomene (Myrtaceae)". Nuytsia. 13 (3): 514–518. Retrieved 23 April 2021.
  4. ^ Pieroni, Margaret (2001), Thryptomene australis, T. duplicata, T. eremaea [art original], [s.n.], retrieved 23 February 2020
  5. ^ "Thryptomene australis". APNI. Retrieved 23 April 2021.
  6. ^ Endlicher, Stephan (1838). "Stirpium Australasicarum Herbarii Hugeliani Decades Tres". Annalen des Wiener Museums der Naturgeschichte. 2: 192. Retrieved 23 April 2021.
  7. ^ Sharr, Francis Aubi; George, Alex (2019). Western Australian Plant Names and Their Meanings (3rd ed.). Kardinya, WA: Four Gables Press. p. 141. ISBN 9780958034180.
  8. ^ "Thryptomene australis subsp. australis". Australian Plant Census. Retrieved 23 April 2021.
  9. ^ "Thryptomene australis subsp. brachyandra". Australian Plant Census. Retrieved 23 April 2021.
  10. ^ a b "Thryptomene australis subsp. australis". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  11. ^ a b "Thryptomene australis subsp. brachyandra". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
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