XCI. An Historical Memoir concerning a Genus of Plants called Lichen, by Micheli, Haller, and Linnæus; and comprehended by Dillenius under the Terms Usnea, Coralloides, and Lichenoides: Tending principally to illustrate their several Uses. Communicated by Wm. Watson, M. D. F.R.S.
——Natura nihil frustra creaverit, posteros tamen tot inventuros utilitates ex Muscis auguror, quot ex reliquis vegetabilibus.
Cui bono? Amæn. Acad. III. p. 241.
Read Apr. 27 & May 4, 1758.
THE whole class of mosses were taken but very little notice of by the revivers of botany in the sixteenth century: they indeed took some pains to distinguish the particular species that the ancients had mentioned, but disregarded almost all the rest. Modern botanists however suppose, that they were but little successful in general in their application of the ancient names to plants: nor is a failure in such attempts to be wondered at, considering the too great conciseness, and frequent obscurity, of their descriptions. In the class of mosses, as in many others, the accounts transmitted to us are little more than a scene of uncertainty and confusion.
It is to the moderns we are indebted for the discovery of the far greater number of the plants of this class. In this branch of botany our own countrymen Mr. Ray, Buddle, Dale, Doody, Petiver, and Dr. Morison, Sherard, Richardson, and others, have distinguished themselves: and amongst foreigners M. Vaillant, Sig. Micheli, and the very eminent Dr. Haller: but, beyond all, the late learned and indefatigable professor at Oxford, Dr. Dillenius, has herein made the most ample discoveries and improvements, of which his elaborate history will ever remain a standing proof.
The word lichen occurs in the writings of Dioscorides and Pliny; and tho’ it may be doubtful, there is nevertheless good reason to apprehend, that Dioscorides meant to describe under that name the very plant, or at least one of the same genus, to which the commentators agreed to affix his description. Since then the name has been variously applied by different authors; on which account it is necessary to premise, that the lichen sive hepatica Off. or liverwort of the shops, does not fall under this generical term, as it is now formed by the three above-named authors. They comprehend under the term Lichen, and Dillenius under those of Usnea, Coralloides, and Lichenoides, the hairy tree-moss or usnea of the shops; the muscus pulmonarius, tree-lungwort, or oak-lungs; the lichen terrestris cinereus, or ash-coloured ground liverwort; the coralline-mosses; the cup-mosses; horned mosses; the orchel, or Canary-weed; the muscus islandicus of Bartholine; and a multitude of others found upon trees, walls, rocks, and stones, in all parts of the world, and in many parts thereof in very great abundance.
Caspar Bauhine in his Pinax, John Bauhine, and countrymen Gerard and Parkinson, and their cotemporaries, as they wrote before the time that generical characters in botany were in use, included these lichens among the other herbaceous mosses, under the general name of muscus; adding to the name in general some epithet descriptive of its form, place of growth, or supposed virtue.
Mr. Ray, both in his History of Plants, and in the Supplement, as he was usually averse to the forming of new names, has interspersed them among other mosses, under the character of musci steriles seu aspermi, retaining the synonyms of the two Bauhines, Gerard, and Parkinson, to the general species.
Dr. Morison seems to have been the first, who separated them intirely from the herbaceous mosses; and, from the analogy he supposed they had with the fungus tribe, formed them into a genus, under the name of musco-fungus. He enumerates fifty species and upwards under this term in the Historia Oxoniensis, and has divided them into five orders, according to their different appearances, as follows: