1920] SHERFF— TARAXACUM 347 



perpetuated here and there through parthenogenetic reproduc- 

 tion. 19 



Taraxacum lividum Heller (exclud. synon. Waldst. et Kit.) is 

 seen, from the specimens cited {A. A. and E. C. Heller 3642), to 

 be likewise a form of T. ceratophorum. Most of the bracts are 

 ecorniculate, thus placing the plants, in Handel-Mazzetti's 

 treatment (loc. cit. 74), with T. lapponkum. 



3. Taraxacum eriophorum Rydb., Fl. Montana, Mem. 

 New York Bot. Gard. 1:454. 1900 (non Schott ex TchihatchefT, 

 Asie mineure 3 2 -372. i860; nomen nudum quod = T. syriacum 

 Boiss., fide Handel-Mazz., Monograph. Taraxacum 162. 1907); 

 T. ovinum Greene, Pittonia 4:229. 1901; T. angustifolium Greene, 

 loc. cit.; T. ammophilum Nels. ex Greene, loc. cit. 233. L. erio- 

 phorum Rydb., Fl. Rocky Mts. 1035. 191 7, L. angustifolium 

 Rydb. loc. cit.; L. ammophilum Rydb., loc. cit. PI. XXXIII. 



Herba polymorpha, nunc pumila et rosulata (forma descrip- 

 tionis orig.), nunc robustior, 3-8 (etiam —30) cm. alta. Radix et 

 folia et scapi eis T. ceratophori non conspicue dissimiles, foliis 

 autem saepius membranaceis et pallidis, rarius profunde pin- 

 natifidis, iuvenilibus raro longe lanuginosis versus basim. Capitula 

 1 . 5-2 . 5 cm. alta et paulo latiora. Involucrum pallidum vel atro- 

 viride. Involucri foliola plerumque ecorniculata vel rarissime ad 

 apicem dilatato-corniculata et plus minusve atrata, exteriora 

 adpressa vel minime patentia, interiorum longitudinis 0.2-0.6 

 aequantia, 4-15 mm. longa, margine plus minusve distincte 

 decolorato. Flores vivi ad anthesin non observati. Achaenia 

 4-5 mm. longa, rufa rufopurpureave, supra tuberculis angustis vel 

 spinulis dense obsita, saepe acute tetragona, in cuspidem crassam 

 vel angustam, et brevem vel quartae parti totius fructus aequantem 

 cuneate attenuata. Rostrum tenue, achaenio paulo vel multo 

 longius. Pappus albus, 4-8 mm. longus. 



Distribution. — -Alberta to Wyoming; a form with highly corniculate 

 bracts occurs in Alaska. 



Specimens examined. — -Alberta: Morley, meadows, etc., June 12, 1885, 

 John Macoun (Hb. Can. 15117); Laggan, June 28, 1905, idem (Hb. Can. 

 65618 and 65619); Waterton Lake, Sheep Mt., July 31, 1895, idem (Hb. Can. 

 1 1 71 1, type of T. ovinum Greene; Hb. Greene 48435). 



19 Concerning the fixation of new colors in Taraxacum achene coats through the 

 operation of parthenogenesis, cf. footnote 24. 



