PDF - CES (IISc)

DISTRIBUTION 351
lichens of Australia and Tasmania to which countries a few tropical species
of Graphis, Chiodecton and Trypethelium have migrated. Various unusual
types are to be found there also: the beautiful Cladonia retepora (Fig. 71),
which spreads over the ground in cushion-like growths, with the genera
Thysanothecium and Neophyllis, genera of Cladoniaceae endemic in these
regions.
The continent of Africa on the north and east is in so close connection
with Europe and Asia that little peculiarity in the flora could be expected.
In comparing small representative collections of lichens, 37 species from
Egypt and 20 from Palestine, Miiller 1 found that there was a great affinity
between these two countries. Of the Palestine species, eight were cosmo-
politan ; among the crustaceous genera, Lecanorae were the most numerous.
There was no record of new genera.
The vast African continent more especially the central region has
been but little explored in a lichenological sense; but in 1895 Stizenberger 2
listed all of the species known, amounting to 1 593, and new plants and new
records have been added since that day. The familiar genera are well
represented, Nephromium, Xanthoria, Physcia, Parmelia, Ranialina and
Roccella, some of them by large and handsome species. In the Sahara
Steiner' found that genera with blue-green algae such as the Gloeolichens
were particularly abundant ;
Heppia and Endocarpon were also frequent.
Algeria has a Mediterranean Flora rather than tropical or subtropical.
Flagey 4 records no species of Graphis for the province of Constantine, and
only 22 species of other Graphideae. Most of the 519 lichens listed by him
there are crustaceous species. South America stretches from the Tropics
in the north to Antarctica in the south. Tropical conditions prevail over
the central countries and tropical tree-lichens, Graphidaceae.Thelotremaceae,
further West, on the Pacific slopes, Usneae and Ramalinae
etc. are frequent ;
hang in great festoons from the branches, while the foliose Parmeliae and
Stictae grow to a large size on the trunks of the trees.
Wainio's 8 Lie/tens du Bresil is one of the classic systematic books and
embodies the writer's views on lichen classification. There are no new
families recorded though a number of genera and many species are new,
and, so far as is yet known, these are endemic. Many of our common forms
are absent thus ; Peltigera is represented by three species only, P. leptoderma,
P. spuriella and P. Americana, the two latter being new species. Sticta
(including Stictina) includes only five species, and Coenogonium three. There
are 39 species of Parmelia with 33 of Lecanora and 68 of Lecidea, many of
them new species.
1
Miiller- Argau 1884.
4
Flagey 1892.
*
Stizenberger 1888-1895.
5 Wainio 1890.
3 Steiner 1895.