Diselma
archeri (Cheshunt Pine) is a native shrub or small tree found in
relatively high rainfall alpine and subalpine areas of central,
western and southern Tasmania. It is very fire sensitive and only
grows in fire-free areas, in alpine conifer heath and montane
rainforest. It is slow growing and may live for many hundreds of
years. Diselma archeri is endemic to Tasmania and is the
only species in this genus. The adult leaves are scale like,
overlapping like tiles and are opposite and decussate so form four
rows up the stem. These leafy stems are only about 1-1.5 mm across
and square in cross section. Seedlings are uncommon (this species
often resprouts from trunks buried in the peat), but have narrow,
spreading leaves a few mm long. The female cones are small (~3-4mm
across) and dry, containing about 4 seeds.
This species is often confused with
Microcachrys tetragona
and Phaerosphaera hookeriana, both of which live in similar
areas to D. archeri. P. hookeriana has similar growth habit to
D. archeri, but has spirally arranged leaves. M. tetragona is
generally prostrate (although D. archeri can also be of
similar size), has no stomata on the outer surface of the leaf and
has conspicuous red fleshy female cones. |