i 9 2o] SHERFB TARAXACUM 357 



minusve elongati. Capitula parva vel mediocria, circum 1-2 cm. 

 longa et paulo latiora. Involucri foliola utriusque seriei circa 

 11-13, pallidius atriusve griseo-viridia, glauco-pruinosa, ecornicu- 

 lata vel plerumque corniculis mediocribus vel parvis instructa. 

 Exterioris seriei foliola adpressa, patentia vel e basi paten ti recurva, 

 interioribus latiora eorumque longitudinis tertiam vel dimidiam 

 partem vix superantia, infima ceteris breviora, omnia late vel 

 angustius ovata vel e basi ovata triangularia (4-8 mm. longa et 

 1 .5-3 mm. lata), margine membranaceo plerumque distinctissimo. 

 Flores numerosi, involucro 2-4 mm. longiores, citrini vel (in 

 speciminibus pinguibus) T. vulgaris tioribus paulo tantum palli- 

 diores, extus plerumque griseo vel rubro striati. Achaenia parva, 

 ±3-4 mm. longa, intense rufa, rufopurpurea vel fere atropur- 

 purea, supra tuberculis longis angustis largis obsita, saepe infra 

 quoque rugulosa, in cuspidem anguste linearem longam, totius 

 fructus tertiam vel quartam partem superantem abrupte contracta. 

 Rostrum tenue, achaenio dimidio vel plus duplo longius. Pappus 

 albus, 4-7 mm. longus. 



Distribution. — Nova Scotia and Virginia to British Columbia, Idaho, 

 and New Mexico; apparently introduced from Europe, where native, as 

 also (fide Handel-Mazz.) in western Asia and northwestern Africa. 



Specimens examined. — Nova Scotia: Yarmouth, John Macoun, June 3, 

 iqio (Hb. Can. 81358). 



Massachusetts: Dorchester, May 24, 1903, John Murdoch, Jr., 1304 

 (Hb. Field 470218); Weston, May 21, 1904, idem 1625 (Hb. Field 470265). 



Vermont: Vergennes, dry knolls in orchard, May, 28, 1899, Ezra Brainerd 

 (Hb. Greene 48444); West Rutland, Twin Mountains, May 31, 1899, II". W. 

 Eggleston 1416 (Hb. U.S. 364398); Shrewsbury, May 25, 1902, idem 2681 



(Hb. U.S. 492337)- 



Pennsylvania: Rohrerstown, April 21, 1891, John K. Small (2 sheets in 

 Hb. Field, 169751 and 169752); vicinity of Conewago, May 14, 1891, idem 

 (Hb. Field 167811). 



District of Columbia: Washington, university grounds, May 2, 1899, 

 Edward L. Greene (Hb. Greene 48443). 



Virginia: North Four Mile Run, May 1898, Ivor Tidestrom (Hb. Greene 

 48441). 



Michigan: Durand, May 15, 1913, Edward L. Greene (Hb. Greene 22276). 



Ohio: Sandusky, July 28, 1903, E. L. Moseley (Hb. Field 240265). 



Illinois: Chicago, in yard, May 1919, Winnifred Baantjer (Hb. Field 

 485106); Urbana, University campus, April 1, 1907, Frank C. Gates "1369.3" 



