Determination of the Cladoniei bfj Hydrate of Potash, 405 



LIII. — NotulcB LichenologiccB. No. XL 

 By the Rev. W. A. Leighton, B.A., F.L.S. 



On the Examination and Rearrangement of the Cladouiei, as 

 tested by Hydrate of Potash. 



In 110 case is the new reactive, hydrate of potash (see Annals & 

 Mag. Nat. Hist. ser. 3. vol. xviii. p. 169), of greater practical 

 utility than in the difficult tribe of the Cladoniei, that crux of 

 lichenologists, where its application enables us with admirable 

 precision and exactness to determine the various species, to re- 

 distribute the confounded species, and to refer to their proper 

 systematic places the innumerable varieties and forms and endless 

 modifications which may resemble each other in external charac- 

 ters. This will be amply manifest to the student by the follow- 

 ing result of its application to the specimens in my herbarium. 

 Where the reactive produces a yellow colour, it may be indicated 

 by this sign, K + ; where no reaction takes place, or only a shght 

 fuscescence, thus, K— . 



Tribe CLADONIEI, Nyl. 

 I. Pycnothelia, Ach., Duf., Nyl. (K-f). 



1. P. papillaria (HofFm.) (Dill. t. xvi. f. 28, E. Bot. t. 907) 

 = Schffir. L. H. 511, 512; Nyl. Lich. Paris. 107; Moug. & 

 Nestl. 259; Leight. Brit. Lich. 208; Mudd, Brit. Lich. 22; 

 Mudd, Brit. Clad. 80; Coemans, Clad. Belg. 1, 2, 3, 4; Anzi, 

 Clad. Cisalp. 27; T. M. Fr. Lich. Scand. 16; Spruce, Lich. 

 Pyren. 



In addition to the above published collections, my herbarium 

 contains the plant from Bagneres (Dr. Philippe), Genoa (Prof. 

 DNtrs.), Smoland, Femsjo (Dr. T. M. Fries), Eperjes, Hungary 

 (Dr. Holzinger), Westmoreland (Mrs. Stanger), Yorkshire (Mr. 

 G. Dixon), Bournemouth, Hants (Rev. A. Bloxam). 



2. P. mascarena, Nyl. Of fhis plant I have seen no specimen; 

 but Dr. Nylander informs me [in litt.) that it has the same 

 reaction (K + ) as P. papillaria. 



II. Cladonia, Nyl. (thallus leafy: see Flora, 1866, p. 178, 

 and Ann. & Mag. Nat. Hist. 3 ser. xviii. p. 105.) 



* Phaocarpce (K + ). 



1. C. endiviafolia, Fr. (Mich. Gen. t. 24. f. 3, E. Bot. t. 2361). 

 The under surface of the thallus becomes of a faint yellow with 

 hydrate of potash, which is not the case with C. alcicornis, thus 

 showing them to be distinct. = Nyl. L. P. 106 ; Schaer. L. H. 

 456; M. & N. 1062; Anzi, C. C. 1, 2; Coem. *620; Welw. 

 Crypt. Lusit. 35. 105 ; Mudd, B. C. 1. 



My herbarium has it alsp from Rome (Dr. Deakin), Modling, 



