Linnccan Society. 377 



LINN/EAN SOCIETY. 



April 2, 1833.— A paper was read, entitled, "On the Modifica- 

 tions of /Estivation observable in certain Plants formerly referred 

 to the Genus Ctinchqna." By Mr. David Don, Libr. L.S. 



The aestivation of corolla is much more varied in monopetalous 

 than in polypetalous flowers, for, with the exception of a portion of 

 the Rutacecz, principally from New Holland and South America, the 

 imbricate form is found almost generally to prevail in the latter 

 class. Among the monopetalous orders the form of aestivation is a 

 character of such high value as oftentimes to afford the only pal- 

 pable distinction to the limitation of families; but the Rubiacece 

 present a striking exception, examples of almost every modification 

 of aestivation being afforded by it; and although among them it is a 

 character of less value, still it will be found materially to assist in 

 distinguishing the genera of that extensive family. 



The genera enumerated and described by the author are Cin- 

 chona, Cosmibuena, Exostema, Uymenodictyon, Luculia, Pinck?ieya, 

 and a new one, founded upon the Cinchona rosea of the Flora Pe- 

 ruviana, which he has named and characterized as follows : — 



Lasionem a. Cinchonas sp. Ruiz et Pavon. 



Calyx 5-dentatus. Corolla tubulosa, limbo 5-fida, sestivatione im- 

 bricatfi. Stamina exserta : Jilamenta medio barbata : anther ce sub- 

 rotundae, peltatae ! biloculares: loculis basi solutis. Stigma bilo- 

 bum. Capsula bilocularis, medio loculicido-dehiscens! polysperma. 

 Semina exigua, samaroidea. Arbor (peruviana) irifl or escentid pani- 

 culate!. 



1. L. roseum. 



This constitutes a very distinct genus, differing from Cinchona 

 not only in its imbricate aestivation, but likewise in the structure of 

 the stamens and in the dehiscence of its capsule. So little has the aes- 

 tivation of corolla been attended to among these plants, that we find 

 the present genus included among the synonyms of Cinchona lan- 

 cifolia in the Nova Genera et Species Plantarwn of Professor Kunth. 



April 16. — Read, " Remarks on a few rare Scottish Plants, chiefly 

 from the Clova mountains." By Mr. David Don, Libr. L.S. 



The mountains of Clova, which bound the upper part of Forfar- 

 shire, have long been famed in the annals of British Botany, as af- 

 fording many of those interesting additions made to the Scottish 

 Flora, by the author's father, the late Mr. George Don, of Forfar, 

 and which the discoveries of more recent investigators have shown 

 to be still far from being exhausted of novelties. 



The vegetation of Clova is remarkable for its comparative luxu- 

 riance, many plants of similar species being found of a more gigan- 

 tic size than are to be met with on Ben Lawers, Ben Nevis, and 

 Cairngorum, and in general they are found at much lower eleva- 

 tions on the Clova range, which may perhaps sufficiently account 

 for their increase in stature. 



Third Series. Vol. 2. No. 1 1. May 1833. 3 C 



