Eucalyptus johnstonii 

Location & distribution maps

Phylogeny & links to associated information:

Wikipedia links:       Angiosperms > Eudicots > Rosids  >  Myrtaceae > Eucalyptus johnstonii

Other links:     

Plant  information

Common name:         Yellow Gum

Conservation status: Near threatened

Etymology:   

•  The name Eucalyptus is from the Ancient Greek words eu meaning 'good'and kalypto meaning '(I) cover, conceal, hide', referring to the operculum covering the flower buds

• The specific epithet honours Robert Mackenzie Johnston

Flowers:                  

• Flower buds in groups of three and flowers are white 

• The flower buds are arranged in leaf axils on a thick, unbranched peduncle 3–10 mm long, the individual buds sessile

• Mature buds are oblong to diamond-shaped, 8–11 mm long and 6–9 mm wide with a rounded operculum with a central knob

• Flowering mainly occurs from February to April and the flowers are white

Fruit:                         

• A woody hemispherical or bell-shaped capsule 7–10 mm long and 9–13 mm wide 

• The valves protrude above the rim of the fruit

Leaves:         

• Young plants and coppice regrowth have stems that are more or less square in cross-section with a broad wing on each corner and sessile

• The juvenile leaves are egg-shaped to almost round, 25–60 mm long, 13–45 mm wide and arranged in opposite pairs

• Adult leaves are lance-shaped or curved, more or less the same glossy green on both sides, 65–150 mm long and 20–40 mm wide on a petiole 15–30 mm long

Stem & branches: 

• It has smooth yellow to brownish or greenish bark, sometimes with persistent fibrous bark near the base

Roots:         

Habit:        

• A species of medium-sized to tall tree

• It typically grows to a height of 40–50 m and forms a lignotuber.

Habitat:   

• Tall forest on mountains and plateaus

Distribution:                  

•  Endemic to Tasmania

• South-eastern Tasmania including on Mount Wellington, Bruny Island and the Tasman Peninsula

Additional notes:     

• Taxonomy 

  • Eucalyptus johnstonii was first formally described in 1922 by Joseph Maiden and the description was published in Volume 6 of his book, A Critical Revision of the Genus Eucalyptus

  • Maiden noted that the species had already been described in 1886 by Thomas Bather Moore

  • Moore gave it the name Eucalyptus muelleri, a name that was already used for a different species, making it an illegitimate name

  • Maiden gave a further description and a diagram of the same species in Volume 3 of his book

Sources of information:

• https://en.wikipedia.org/wiki/Eucalyptus_johnstonii (2023)