Fascinating Lichens of Sri Lanka

40 Fascinating Lichens of Sri Lanka
is changing rapidly, and it is difficult for available information in print and even
online to keep up. Collections of data for many species (even some species listed
on this book) are scant, and many older identifications (based on literature and
collections of Sri Lanka) are questionable. Therefore, the true range of many
species, especially crustoses, is largely unknown. Published information often
reflects where collectors have gone as much as where the species actually grow.
The potential for trained collectors and naturalists to make a real contribution to
our knowledge of Sri Lankan lichens, therefore, is substantial.
It is better to keep in mind that lichen classification is changing rapidly
though lichens evolve slowly.
One of the fascinating aspects about lichens is that a species which is generally
uncommon, may be strikingly abundant in one area. I recall that I had not
encountered Hypogymnia zeylanica anywhere in Sri Lanka until I went to a
particular spot in Horton Plains, where suddenly it seemed to be on almost all
the trees. If you see this species, you might think this is a common species, but I
have not encountered it anywhere else except for very specific places in Horton
Plains and few adjacent locations. I think this element of surprise is one of the
most satisfying rewards of looking for lichens, along with the fact that they grow
in all of the wildest and most beautiful environments.
4. Some Fascinating
Lichens of Sri Lanka
4.1 About this Book
This is a preliminary treatment of the fascinating lichen flora of Sri Lanka. This
book includes a few conspicuous lichens that can be easily spotted by any
naturalist. The majority of these lichens are found in high elevation montane
habitats. Many species included in the book can be found in the Horton Plains,
Hakgala Botanical Gardens, many places in Nuwara Eliya, the National Botanical
Garden in Peradeniya and Adam’s Peak (Sri Pada).
It is necessary to emphasize a caveat about this book. This is a first attempt to
compile a lichen field guide for Sri Lanka, and to provide information about the
distribution and ecology of a few species in Sri Lanka. Some of the treatments
are preliminary, and in a few cases, as indicated in the text, there is considerable
uncertainty regarding the application of a name for several species. Even with a
few uncertainties, a field guide book such as this can be a useful tool in gaining
an understanding of the local lichen biota and facilitating the availability of
accessible information. Out of hundreds of known lichen species in Sri Lanka,
this book includes few of the macrolichens and very few conspicuous crustose
genera with few examples.
A serious observer will undoubtedly find many lichens that are not mentioned
here since there are over 1000 lichens known from the country. I have not
provided keys or extensive descriptions. Readers who wish to confidently identify
lichens will need to consult primary sources. I would also encourage readers to
consult the keys to lichens that are found in other published sources, as keys are
the quickest route to identification. The Bibliography of this book lists some of
the important books on lichens, scientific journals that regularly publish articles,
and a number of useful online resources. A number of lichens can be found with
good photographs and extensive descriptions on the internet.
In this guide, the lichens are arranged alphabetically by genus. For each genus
included in this book, there is a heading with the genus (Genus), family (F),
Order (O) and how many species are known in the world for each genus (W)
followed by a brief synopsis of diagnostic features. This synopsis pertains only
to those members of the genus listed in the book, and not necessarily to all
members of the genus. Information on morphology, chemistry, and ecology
is for the most part derived from central highland material, with emphasis on
the lower elevations. In a few instances, I have based my comments on other
Asian and temperate material, or relied on literature reports for taxa, particularly
regarding sexual characters for species which are mostly sterile in Sri Lanka.
Each lichen included in the book is given the species name, standard coding
acronym used on field data (when available), and the growth form (foliose,
fruticose, crustose etc.). This is followed by distribution, habitat, ecology, and
any other information of importance about the lichen, as well as any diagnostic
information on chemical constituents for further characterization of the species.
The descriptions include distinguishing traits with as little technical jargon as
possible. Thallus details include colour, shape, and unique features. Apothecia
details are limited to where appropriate. Chemistry is included only when it is
necessary to identify the species. Positive identification of lichens often requires
chemical testing (it is best to do the chemical tests under a microscope when
lichens are collected for further studies). The special notes include tips for field
identification characteristics and similar species with which the subject lichen
may be confused.
Fascinating Lichens of Sri Lanka 41