Diselma archeri

Diselma archeri (dwarf pine or Cheshunt pine) is a species of plant of the family Cupressaceae and the sole species in the genus Diselma. It is endemic to the alpine regions of Tasmania's southwest and Central Highlands, on the western coast ranges and Lake St. Clair. It is a monotypic genus restricted to high elevation rainforest and moist alpine heathland. Its distribution mirrors very closely that of other endemic Tasmanian conifers Microcachrys tetragona and Pherosphaera hookeriana.

== Appearance and ecology == thumb|left| Scale-like leaves appear in a square in cross section and red coloration of juvenile cone formation. Photo: R. Wiltshire thumb|left|240x150px|D. archeri cones Diselma archeri is a compact, prostrate shrub which commonly reaches 1–4 m in height but has been recorded to reach greater heights in subalpine rainforest zones. The foliage has a grey-green appearance with branchlets curving downward at their tips. Branches are short, ridged and very numerous. 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. The square leaf arrangement is similar to that of Microcachrys tetragona (Podocarpaceae) (creeping pine) and the two species can easily be confused. However, M. tetragona lives up to its name and grows low to the ground, spreading out with only occasional erect branches. Another species which can be confused with Diselma is Phaerosphaera hookeriana (previously known as Microstrobos niphophilus ) which is in the family Podocarpaceae. Both these species have a similar growth habit and distribution, however, the opposite pairs of leaves on D. archeri again make it distinguishable from the other species. Bark is rough and scaly and often weathered revealing a reddish-brown inner bark. 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).