Little work has been done on the lichens of Madagascar, so while over 500 species of lichens have been documented, more are expected.[1] Madagascar can be divided into two major habitats that can be associated with lichen distribution. Wet tropical areas of siliceous bedrock make up approximately two-thirds of the country, and are where most of the lichens have been documented. Dry tropical areas of granitic and limestone bedrock make up the other one-third of the country with just over 20 species documented in these habitats.[1] The following table lists the species known from the dry tropical habitats. The majority are corticolous species that grow on the bark of trees or shrubs. A few are saxicolous; species that grow on rocks.
| SPECIES | TYPE | ||
|---|---|---|---|
| Canoparmelia quintarigera Aptroot | Corticolous | ||
| Clandestinotrema minutum Aptroot | Corticolous | ||
| Contrictolumina leucostoma (Müll. Arg.) Lücking & al. | Corticolous | ||
| Crespoa inhaminensis (C. W. Dodge) Lendemer & B. P. Hodk. | Corticolous | ||
| Dermatiscum thunbergii (Ach.) Nyl. | Saxicolous | ||
| Dirina madagascariensis Tehler & al. | Corticolous | ||
| Dirinaria complicata D. D. Awasthi | Corticolous | ||
| Glyphis scyphulifera (Ach.) Staiger | Corticolous | ||
| Isalonactis madagascariensis Ertz. & al. | Corticolous | ||
| Lecanora helva Stizenb | Corticolous | ||
| Lecanora leprosa Fée | Corticolous | ||
| Lecanora subflava Tuck. | Corticolous | ||
| Lecanora tropica Zahlbr. | Corticolous | ||
| Mycoporum californicum (Zahlbr.) R. C. Harris | Corticolous | ||
| Opegrapha varians (Müll. Arg.) Vain. | Corticolous | ||
| Roccella africana Vain. | Corticolous | ||
| Roccella applanata M. Choisy | Corticolous | ||
| Roccella belangeriana D. D. Awasthi | Corticolous | ||
| Roccella boryi Delise ex Fée | Corticolous | ||
| Roccella linearis (Ach.) Vain. | Corticolous | ||
| Roccella montagnei Bél. | Corticolous | ||
| Sclerophyton madagascariense Sparrius | Corticolous | ||
| Xanthoparmelia subflabellata (J. Steiner) Hale | Saxicolous |
While many of the lichens found to date in Madagascar are relatively widespread, tropical species,[1] some are endemic. Isalonactis madagascariensis, for example, is known only from its type locality near Isalo National Park,[2] and new species continue to be found.[1]