A Grammatical Dictionary of Botanical Latin

rarescens,-entis (part.B): becoming rare, diminishing, dying away [> L. raresco,-ere (part.B), to grow thin, lose its density, to become rare, be rarefied; to become empty, depopulated; diminish, die away (after Lewis & Short);

- [lichen] in apricis fere ubique terrarum distributa inde a regionibus arcticis usque in Australiam et zonam antarcticam; attamen in zona calida rarescens vel evanescens, vixque ibi nisi in montanis elevatioribus obveniens (Nyl.), distributed in the open places of the lands nearly everywhere from there from arctic regions to Australia and the antarctic zone; and yet becoming rare or disappearing in the hot zone, and hardly encountered there except in the higher mountains.

- [lichen] in terris vero arctícis et subarctieis praesertim fréquentes sunt Cladoniae; in calidioribus et numero individuorurn rarescunt et paucae evadunt (Nyl.), but mainly in arctic and subarctic lands the Cladonias are frequent; in warmer regions they become diminished in the number of individuals and few occur.

- [lichen] supra terrain in ericetis et collibus sylvaticis totius Europae, in septentrionali rarescens, in media frequentissima et plurimis formis ludens (Nyl.), diminishing on the ground in the heathlands and wooded hills of all Europe, in the north [sc. terra, region], most frequent in the middle [sc. region] and varying [i.e. mutating] into very many forms.