Diselma

It is endemic to the alpine regions of Tasmania's southwest and Central Highlands, on the western coast ranges and Lake St. Clair.

Branchlet foliage appears square in cross-section and scale-like leaves (2–3 mm) are overlapping and arranged in opposite decussate pairs which are pressed close to the stem.

Being a gymnosperm no flowers are produced, instead seed development occurs on the surface of the scale-like leaves which are modified to form cones (see image).

archeri is named after botanical collector William Archer (1820-1874) who was also a Fellow of the Linnaean Society, an architect and Member of Parliament for Deloraine, Tasmania.

[9] Diselma archeri is endemic to Tasmania and is only found in high rainfall alpine and subalpine areas of the South West and Central Plateau of the state.

[13] This evidence indicates that Diselma archeri is most likely a paleoendemic and is the last remaining species in a genus that was once more extensive and has refuged to specific alpine zones due to changing climate.

Scale-like leaves appear in a square in cross section and red coloration of juvenile cone formation. Photo: R. Wiltshire
D. archeri cones
Distribution map of Diselma archeri showing restriction to the South West and Central Plateau of Tasmania
A simplified phylogeny derived from molecular analysis [ 10 ] showing the phylogenetic relationship of Diselma to closely related genera in the Cupressaceae. Diselma' s closest relative appears to be the South American genus Fitzroya .