312 L'Abbe E. Coemans on the Cladoniso 



Florke (Cora. p. 81. obs. 2) accuses Acharlus with having 

 described, under the name of Cen. pitijrea acuminata, only a 

 form of Clad, furcata ; but the Acharian herbarium shows that 

 this I'eproach is unmerited. 



The C. pityrea (Ach.), which, in my opinion, is nothing but a 

 variety of C. pyx'idata, gives rise to a great number of forms, 

 which are found nearly alike in all the countries of Europe. 

 These forms are, for the most part, wanting in the Acharian 

 herbarium. I have found therein only the form Isigmji sea- 

 hrida, Del., mixed with the var. acuminata, Ach., or designated 

 by M. Leon Dufour under the name of Cen. delicata. 



Some specimens of C. squamosa from Switzerland are marked 

 in the Acharian herbarium, Cen. pityrea ? 



12. Cladonia fimhriata, (Ach.) Syn. p. 254 et hb. ejusd. 



All botanists know how polymorphous this species or, rather, 

 \\\\^ viiv. 0^ C. pyxidata is. Thus Acharius, in distinguishing 

 the different modifications, established eight subvarieties or 

 forms of the type, and two varieties more remarkable. Never- 

 theless this author did not know many important forms of this 

 Cladonia, c. g. C. glauca, Elk., ochrochlora, ¥lk., pyxidata fruti- 

 culosa, Elk., pyxidata fastigiata. Elk., and nyxidata pterygota, 

 Elk. 



As to the two Acharian varieties, they are so little remarkable, 

 that they may be, without any inconvenience, referred to the 

 type. The var. conista, especially, with its two subvarieties 

 exilis and macra, is in reality altogether insignificant. The var. 

 carneo-pallida is distinguished only by its pale or rose-coloured 

 apothecia — a peculiarity which is observable in many species of 

 this genus, e. g. in C. gracilis, furcata, furcata var. pungens, 

 squamosa, and degenerans, and which is frequently only the 

 result of a kind of etiolation. Moreover Acharius has con- 

 founded with this variety the C. carneola, Er. 



As to the forms of the type, they may be reduced to two — 

 the form tubaformis, comprehending the subvarieties carpo- 

 phora and yrolifera of Acharius, and the form cornuto-radiata, 

 comprising the subvarieties radiata, ahortiva, fibula, comuta, and 

 nemoxyna of the same author. 



In species so polymorphous as the present one, it is incum- 

 bent on us to avoid the creation of varieties with too narrow 

 limits, since otherwise the characters are applicable only to a 

 certain number of selected forms, whilst science is embarrassed 

 and our herbaria encumbered with the host of remaining inter- 

 mediate forms. Thus, although Elorke has established more 

 than twenty varieties or forms of C, pyxidata, I have found in 



