Eucalyptus × balanopelex

Eucalyptus × balanopelex is a mallee that typically grows to a height of 4 metres (13 ft) and forms a lignotuber. It has smooth pale grey to brownish bark throughout. The leaves on young plants and on coppice regrowth are dull green, egg-shaped, 60–110 mm (2–4 in) long, 35–50 mm (1–2 in) wide and always have a petiole. Adult leaves are lance-shaped, sometimes broadly lance-shaped, 65–120 mm (3–5 in) long and 13–30 mm (0.5–1 in) wide with a petiole 10–25 mm (0.4–1 in) long. The adult leaves are usually the same glossy green on both side and have a dense network of veins. The flowers are arranged in groups of seven or nine in leaf axils on a pendulous peduncle 8–25 mm (0.3–1 in) long, the individual flowers on a pedicel 3–9 mm (0.1–0.4 in) long. The mature buds are oval, 12–19 mm (0.47–0.75 in) long and 5–9 mm (0.20–0.35 in) wide with a conical operculum about 50% longer than the floral cup. The flowers are creamy-white and the fruit is a hemispherical capsule, 8–10 mm (0.31–0.39 in) long and 9–12 mm (0.35–0.47 in) wide with the valves protruding above the rim.[2][3]

The Australian Plant Census lists this species as a natural hybrid between E. kessellii subsp. eugnosta and E. semiglobosa.[1]

Eucalyptus × balanopelex was first formally described in 1992 as Eucalyptus balanopelex by Lawrie Johnston and Ken Hill who published the description in the journal Telopea.[3][4] The specific epithet (balanopelex) is derived from the Ancient Greek words balanos meaning "acorn" or "barnacle",[5]^: 68 and pelex meaning "a helmet",[5]^: 594 referring to the shape of the operculum.[3]

This eucalypt grows on a low-lying sandplain near Esperance.[2]

In 2012, Dean Nicolle and Malcolm French proposed that E. balanopelex is a hybrid of E. kessellii subsp. eugnosta and E. semiglobosa and should be delisted from the list of threatened flora.[6] It is no longer listed by FloraBase.[7]

• List of Eucalyptus species