i92o] SIIERFF— TARAXACUM 



355 



i 





Bermuda Isls.: Flatts, roadsides, August 16, 1913, F. S. Col/ins 314 

 (Hb. Field 464861); Agar's Isl., "not abundant," December 4, 1915, idem 

 430 (Hb. Field 464906). 



Jamaica: Cinchona, alt. 4900 ft., in 1910, Wm. Harris 10926 (Hb. Field 



294859). 



As previously stated, T. vulgare tends to pass into T. cerato- 

 phorum in the northeastern part of North America. The T. ojfici- 

 nale var. palustre of Gray's Manual (ed. 7, p. 865, fig. 1015. 1908) 

 includes some of these transitional forms; so also does T. latilobum 

 DC, collected originally in Newfoundland ("in vol. squamis 

 ecorniculatis, exter. patulo-reflexis .... proxime ad Dentem- 

 leonis accedit," -DC, loc. cit.). Murdoch 1624, from Massachusetts 

 (Hb. Field 470264) is typical of the Gray's Manual illustration, 

 and yet is easily recognized as being true T. vulgare. Fernald and 

 Collins 263 (Hb. U.S. 606098) from Quebec has the involucres 

 fairly typical of T. vulgare, but in general habit it approaches 

 T. ceratophorum; in fact, it was originally under the latter name. 

 Sornberger 64X (Hb. U.S. 41 1050) from Labrador is still another 

 form of T. vulgare. Its involucres are of the T. vulgare kind; but 

 the foliage exactly matches that of Fernald 9 s Grand River plant of 

 Quebec (Hb. U.S. 605794), a plant that from involucral characters 

 is seen however to be T. ceratophorum. Plants collected by L. M. 

 Turner at Davie's Inlet, Labrador (Hb. U.S. 222755), have involu- 

 cres clearly representing T. vulgare, but the foliage is very strange 

 and is closer to that of T. ceratophorum, although not typical for 

 that species. It seems entirely probable that a number of these 



intermediate forms are hybrids. 



T. mexicanum DC is retained as a valid species by Handel- 

 Mazzetti, who had seen at least nine specimens of Bkrlaxdier's 

 original type material, but I have seen no specimens of Taraxacum 

 from Mexico that were not plainly T. vulgare. Even the excellent 

 cotype specimen studied (in Hb. Boiss.) matches much of the 

 T. vulgare material of the northern United States in foliage, in 

 I fruit, and in involucre. Xor does Handel-Mazzetti's description 



indicate any truly distinctive characters. Thus, for example, he 

 describes the cusp of the achenes as being long in T. mexicanum 

 and short or very short in T. vulgare, but there are numerous 





