Eucalyptus × balanopelex is a mallee that is endemic to a small area of the south-west of Western Australia. It has smooth bark, broadly lance-shaped adult leaves, flower buds in groups of seven, creamy-white flowers and hemispherical fruit. It is thought to be a hybrid between E. kessellii subsp. eugnosta and E. semiglobosa.
Eucalyptus × balanopelex is a mallee that typically grows to a height of 4m (13feet) 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, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide and always have a petiole. Adult leaves are lance-shaped, sometimes broadly lance-shaped, NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide with a petiole NaNsigfig=1NaNsigfig=1 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 NaNsigfig=1NaNsigfig=1 long, the individual flowers on a pedicel NaNsigfig=1NaNsigfig=1 long. The mature buds are oval, NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide with a conical operculum about 50% longer than the floral cup. The flowers are creamy-white and the fruit is a hemispherical capsule, NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide with the valves protruding above the rim.[1] [2]
The Australian Plant Census lists this species as a natural hybrid between E. kessellii subsp. eugnosta and E. semiglobosa.
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] The specific epithet (balanopelex) is derived from the Ancient Greek words balanos meaning "acorn" or "barnacle",[4] and pelex meaning "a helmet", referring to the shape of the operculum.
This eucalypt grows on a low-lying sandplain near Esperance.
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.[5] It is no longer listed by FloraBase.