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Eucalyptus xanthonema

From Wikipedia, the free encyclopedia

Yellow-flowered mallee
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Myrtales
Family: Myrtaceae
Genus: Eucalyptus
Species:
E. xanthonema
Binomial name
Eucalyptus xanthonema
Synonyms[1]

Eucalyptus redunca var. angustifolia Benth.

Eucalyptus xanthonema, commonly known as yellow-flowered mallee,[2] is a species of mallee that is endemic to the south west of Western Australia. It has smooth bark, linear adult leaves, flower buds in groups of up to eleven, white to pale lemon-coloured flowers and barrel-shaped fruit.

Description

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Eucalyptus xanthonema is a mallee that typically grows to a height of 1–5 m (3 ft 3 in – 16 ft 5 in) and forms a lignotuber. It has smooth grey and brownish bark that is shed in ribbons that sometimes accumulate near the base. Young plants and coppice regrowth have soft, thin, bluish green, linear to lance-shaped leaves that are 60–80 mm (2.4–3.1 in) long and 7–10 mm (0.28–0.39 in) wide. Adult leaves are the same shade of green on both sides, linear, 35–77 mm (1.4–3.0 in) long and 3–11 mm (0.12–0.43 in) wide, tapering to a petiole 3–17 mm (0.12–0.67 in) long. The flower buds are arranged in leaf axils in groups of seven to eleven on an unbranched peduncle 5–10 mm (0.20–0.39 in) long, the individual buds on pedicels 2–4 mm (0.079–0.157 in) long. Mature buds are spindle-shaped, 9–16 mm (0.35–0.63 in) long and 3–4 mm (0.12–0.16 in) wide with a conical operculum that is up to twice as long as the floral cup. Flowering occurs from September to December or from January to February and the flowers are white to pale lemon yellow. The fruit is a woody, barrel-shaped capsule 5–8 mm (0.20–0.31 in) long and 4–5 mm (0.16–0.20 in) wide with the valves near rim level.[2][3][4]

Taxonomy and naming

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Eucalyptus xanthonema was first formally described in 1847 by Nikolai Turczaninow in the journal Bulletin de la Société Impériale des Naturalistes de Moscou.[5][6] The specific epithet (xanthonema) is derived from ancient Greek words meaning "yellow" and "thread", referring to the colour of the dried flowers.[3]

In 1991, Ian Brooker and Stephen Hopper described two subspecies and the names are accepted by the Australian Plant Census:[7]

  • Eucalyptus xanthonema subsp. apposita Brooker & Hopper[8] has broader leaves (up to 15 mm (0.59 in) wide) that the autonym;[7]
  • Eucalyptus xanthonema Turcz. subsp. xanthonema[9] has leaves that are 10 mm (0.39 in) wide or less.[7]

Distribution and habitat

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The yellow-flowered mallee grows in low mallee shrubland on plains and gentle slopes between Williams, the Stirling Range and the Fitzgerald River National Park. Subspecies apposita is restricted to the Stirling Range.[3][4]

Conservation status

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Both subspecies of E. xanthonema are classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.[2][10][11]

See also

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References

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  1. ^ a b "Eucalyptus xanthonema". Australian Plant Census. Retrieved 23 January 2020.
  2. ^ a b c "Eucalyptus xanthonema". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  3. ^ a b c "Eucalyptus xanthonema subsp. xanthonema". Euclid: Centre for Australian National Biodiversity Research. Retrieved 27 May 2020.
  4. ^ a b Chippendale, George M. "Eucalyptus xanthonema". Australian Biological Resources Study, Department of the Environment and Energy, Canberra. Retrieved 23 January 2020.
  5. ^ "Eucalyptus xanthonema". APNI. Retrieved 23 January 2020.
  6. ^ Turczaninow, Nikolai (1847). "Decas tertia generum adhuc non descriptorum, adjectis descriptionibus nonnullarum specierum Myrtacearum xerocarpicarum atque Umbelliferarum imperfectarum". Bulletin de la Société impériale des naturalistes de Moscou. 20 (1): 163–164. Retrieved 23 January 2020.
  7. ^ a b c Brooker, M. Ian H.; Hopper, Stephen (1991). "A taxonomic revision of Eucalyptus wandoo, E. redunca and allied species (Eucalyptus series Levispermae Maiden Myrtaceae) in Western Australia". Nuytsia. 8 (1): 125–131. Retrieved 23 January 2020.
  8. ^ "Eucalyptus xanthonema subsp. apposita". Australian Plant Census. Retrieved 23 January 2020.
  9. ^ "Eucalyptus xanthonema subsp. xanthonema". Australian Plant Census. Retrieved 23 January 2020.
  10. ^ "Eucalyptus xanthonema subsp. apposita". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  11. ^ "Eucalyptus xanthonema subsp. xanthonema". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.