Eucalyptus castrensis, commonly known as Singleton mallee[1] or Pokolbin mallee box,[2] is a species of mallee that is endemic to a small area of New South Wales in eastern Australia. It has mostly smooth bark, lance-shaped adult leaves, flower buds in groups of seven, white flowers and cup-shaped fruit.
Eucalyptus castrensis is a mallee that typically grows to a height of 8m (26feet). It has smooth bronze-grey bark but older stems sometimes have a collar of rough bark near the base. Young plants have dull bluish green, egg-shaped to lance-shaped leaves that are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Adult leaves are glossy green, lance-shaped, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide on a petiole NaNsigfig=1NaNsigfig=1 long. The flower buds are arranged in groups of seven on a peduncle NaNsigfig=1NaNsigfig=1 long, the individual buds on a pedicel long. Mature buds are oval, NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide with a conical operculum. Flowering has been observed in August and the flowers are white. The fruit is a woody, cup-shaped capsule, NaNsigfig=2NaNsigfig=2 long and NaNsigfig=2NaNsigfig=2 wide with the valves well below the rim.[3] [4] [5]
Eucalyptus castrensis was first formally described in 2002 by Ken Hill from a specimen collected on the Singleton Army Base and the description was published in the journal Telopea'.[6] The specific epithet (castrensis) is derived from the Latin word castra meaning "camp"[7] with the suffix -ensis meaning "of" or "from", referring to the occurrence of this eucalypt in the grounds of an army base.
Singleton mallee is only known from a single dense stand on an army base near Singleton where it grows on a low, broad sandstone ridge.
This eucalypt is listed as "endangered" under the New South Wales Government Biodiversity Conservation Act 2016.