MIDDLESEX FLOEA. 59 



G. fcBtida, Zi. 

 Westford, woollen-mill yard (Dr. C. W. Swan). Adv. from Eu. 

 "Stem erect, leafy, branching, hairy; leaves hairy, runcinate- 

 pinnatiftd, the uppermost lanceolate, deeply incised at the base ; 

 peduncles drooping before flowering; beaks of the marginal 

 achenia shorter than the involucre, those of the interior longer ; the 

 entire involucre downy and villous; hairs simple and glandular; 

 bracts of the involucre lanceolate, acute." Koch, Syn. El. Germ. 



Pebnanthes, Vaill. 

 P. alba, L. (Nabalus albus, Hook., Man.) White Lettuce. 



Common. Aug.-Sept. 

 P. altissima, L. (Nabalus altissimus. Hook., Man.) Tall White 



Lettuce. 



Common. Aug.-Sept. . 

 P. serpentaria, Pursh. (Nabalus Fraseri, DC, Man.) Lion's 



Foot. Gall-op-the-earth. 



Tewksbury and Winchester (Dr. C. W. Swan) ; Belmont and 



Arlington (C. E. Perkins) ; Medf ord (Wm. Boott) ; Waltham List ; 



Concord (Minot Pratt) . Not common. Aug.-Sept. 



Taraxacum, Hall. 

 T. officinale, Weber. (T. Dens-leonis, Desf ., Man.) Dandelion. 



Very common. Apr.-July. 



Lactuca, Tourn. 

 L. Canadensis, L. Wild Lettuce. 



Common. Aug.-Sept. 

 L. integrifolia, Bigel. (L. Canadensis, var. iutegrifolia, Torr. & 



Gray, Man.) 



Tewksbury (Dr. C. W. Swan) ; Maiden and Melrose (F. S. Collins). 



Not very common. Aug.-Sept. 

 L. hirsuta, Muhl. (L. Canadensis, var. sanguinea, Torr. & Gray, 



Man.) 



Lowell (Dr. C. W. Swan) ; Maiden, Melrose, et al., not rare (F. S. 



Collins). Aug.-Sept. 

 L. ScAEiOLA, L. Prickly Lettuce. 



Maiden (F. S. Collins) ; Somerville (C. E. Perkins) ; Cambridge 



(Wm. Boott). Not common. Aug. Nat. from Eu. 

 L. leucophaea. Gray. (Mulgediuin leucophseum, DC, Man.) 



Blue Lettuce. 



Widely distributed ; not uncommon. Aug.-Sept. 



SONCHUS, L. 



S. oleraceus, L. Sow-thistle. 

 Maiden, Somerville, Westford, Framingham, et al. Not uncommon. 

 Nat. from Eu. 



