Eucalyptus costuligera

Eucalyptus costuligera is a tree that typically grows to a height of 5–10 m (16–33 ft) and has persistent pale grey, fibrous or flaky "box"-type bark on the trunk and branches. The adult leaves are arranged alternately, the same grey-green or bluish colour on both sides, lance-shaped, 70–150 mm (2.8–5.9 in) long and 17–30 mm (0.67–1.18 in) wide on a channelled or flattened petiole up to 22 mm (0.87 in) long. The flower buds are arranged in groups of up to seven on a branched or unbranched peduncle 1–15 mm (0.039–0.591 in) long, the individual buds on a pedicel 2–6 mm (0.079–0.236 in) long. Mature flower buds are club-shaped, about 7 mm (0.28 in) long and 4 mm (0.16 in) wide with faint ribs along the sides. The operculum is hemispherical, about half as long as the floral cup. The flowers are a white-cream colour and the fruit is a woody cylindrical, cup-shaped or pear-shaped capsule 6–8 mm (0.24–0.31 in) long and 5–7 mm (0.20–0.28 in) wide with fine ribs along the sides and the valves enclosed below the rim.[3][4][5]

Eucalyptus costuligera was first formally described in 2000 by Lawrie Johnson and Ken Hill from a specimen collected 60 km (37 mi) from the Derby-Gibb River Road, on the road to Wyndham.[4][6] The specific epithet (costuligera) is derived from the Latin costula, meaning "a costule or rib" (strictly the midrib of a fern frond) and -ger meaning "-bearing", referring to the finely ribbed fruit.[4][7]

This eucalypt has a limited range but is abundant in a small area in the central Kimberley region of Western Australia, growing in savannah woodland in sandy to loamy soils over laterite.[5][4]

This species is classified as is classified as "Priority One" by the Government of Western Australia Department of Parks and Wildlife[5] meaning that it is known from only one or a few locations which are potentially at risk.[8]

• List of Eucalyptus species