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1920] SHERFF— TARAXACUM 



S49 



nearly mature ones (for example, Hb. U.S. 541188) are distinctly 

 reddish. Thus Rydberg's type plants are seen to be connected 

 perfectly with the type material of T. ammo philum , and, from 

 priority, the name T. eriophorum must have the preference. 



The type material of T. ovinum Greene, from Alberta, consists 

 of several small, more or less dwarfed and immature specimens. 

 The achenes in the oldest head found (in Hb. Can.), while not yet 

 very reddish, have the acutely tetrangular shape that I have 

 observed in numerous other mature specimens of T. eriophorum. 

 The involucre, although sometimes duplicated by T. ceratophomm, 

 is more typical of T. eriophorum. and there remains no doubt that 

 T. ovinum is purely synonymous with T. eriophorum. 



T. angustifolium Greene was founded upon three specimens 



from Dale Creek, Wyoming. The leaves and scapes are much 



better developed than in T. ovinum, the scapes reaching a height 



of over 2.5dm.; but the technical characters of the head are 



I essentially the same. Moreover, the numerous mature achenes 



I are definitely reddish in color. Greene (loc. cit. 232) termed 



their color "chestnut brown/' but inaccurately so, for the color 

 is fully as reddish as in many genuine specimens of the red-achened 

 T. laevigatum. The leaves are rather long, slender, and graceful, 

 but certainly do not serve to separate the plants specifically from 

 true T. eriophorum. 22 



Handel-Mazzetti (loc. cit.) has omitted T. eriophorum Rydb. 

 entirely from his monograph, and it is evident that he was entirely 

 unfamiliar with it. The species is closely parallel with T. cerato- 

 phomm, from which it differs in having red achenes and in having 

 the bracts much more often slender and without dilated tips. 

 One might w r onder whether it may be only a form of T. ceratophomm 

 in which the achenes are red. Various investigators have shown 



that apogamy or parthenogenesis is frequent in Taraxacum. 23 

 Schkorbatow (Entwickelungsgeschichtliche Stud, an Taraxacum 

 officinale Wigg., Bot. Institut. Charkow, p. 50. 1910) also states 



22 Almost the exact counterpart to this foliage is sometimes observed in a form 

 of T. ceratophomm (for example, Mendenkall, Valley of Alatna River, Hb. U.S. 37735°)- 



2 3 For references to the experiments and observations of Rauxkiaer, Murbeck f 

 Juul, and others, see Ikeno, Ber. Deutsch. Bot. Gesells. 28:394. 19 10. 



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