Biology:Eucalyptus steedmanii

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Short description: Species of eucalyptus

Steedman's gum
Eucalyptus steedmanii.jpg
Eucalyptus steedmanii on the Hyden-Norseman Road
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Myrtales
Family: Myrtaceae
Genus: Eucalyptus
Species:
E. steedmanii
Binomial name
Eucalyptus steedmanii
C.A.Gardner[1]

Eucalyptus steedmanii, commonly known as Steedman's gum[2] or Steedman's mallet,[3] is a species of mallet that is endemic to a small region of Western Australia. It has smooth, satiny bark, narrow elliptical leaves, flower buds in groups of three, white flowers and conical, four-winged fruit.

Description

Eucalyptus steedmanii is a mallet that typically grows to a height of 2–12 m (6 ft 7 in–39 ft 4 in) and does not form a lignotuber. The bark is smooth and satiny, ranging from grey to red-brown or a bright coppery colour. It has numerous ascending branches from low on the trunk, forming a dense crown. Adult leaves are the same glossy, olive-green on both sides, crowded with oil glands, narrow oblong to elliptical, 30–85 mm (1.2–3.3 in) long and 6–15 mm (0.24–0.59 in) wide. The flower buds are arranged in leaf axils in groups of three on a downturned, unbranched peduncle 15–31 mm (0.59–1.22 in) long, the individual buds on pedicels 12–20 mm (0.47–0.79 in) long. Mature buds are yellowish-brown, spindle-shaped and square in cross-section, 20–32 mm (0.79–1.26 in) long and 9–14 mm (0.35–0.55 in) wide, the operculum splitting into four as the bud develops. It blooms between January and March producing white flowers. The fruit is a woody, conical, four-winged capsule 14–20 mm (0.55–0.79 in) long and 13–22 mm (0.51–0.87 in) wide with the valves near rim level.[3][4][5][6]

Taxonomy and naming

Eucalyptus steedmanii was first formally described by the botanist Charles Gardner in 1933 in the Journal of the Royal Society of Western Australia from a specimen collected by Henry Steedman south of Southern Cross in 1928.[7][8] The specific epithet (steedmanii) honours Steedman.[3]

Distribution and habitat

Steedman's gum is found on low hills and undulating plains between Ravensthorpe in the Goldfields-Esperance and Kondinin in the Wheatbelt region where it grows in gravelly loamy soils over ironstone.[2] Six populations are known, five of these occur on unallocated Crown land, and one which is split occurs on Crown land and a road verge. It is estimated that there is a total population of 24 500 mature plants that are spread over an area of 83.6 square kilometres (32 sq mi) and tend to occur in pure stands.[4]

Conservation status

This mallet was listed as Vulnerable in 2008 under the Environment Protection and Biodiversity Conservation Act 1999 and as "Threatened Flora (Declared Rare Flora — Extant)" by the Department of Environment and Conservation (Western Australia).[2][4] The main threat to the tree is fire which kills adult plants, but regeneration by seed has been observed. Other threats include mining operations, firebreak maintenance and recreation activities.[4]

See also

References

Wikidata ☰ Q15355733 entry