1924] Flora of the Boston District, — XLIV 59 
Robinson, Aug. 5, 1879); shore of Winter Pond, Winchester (K. M. 
Wiegand, Sept. 28, 1908). 
A. undulatus L. X novi-belgii L. See M. L. Fernald, RHODORA 
iv. 186-187, 1902. Damp sandy thicket, Carlisle (Miss E. L. Shaw, 
October 1900 and 1901). 
Other hybrids have been reported for this genus in our area, but 
none of them has been published. As some of the species show a 
great natural variability, and the question of the origin of the reported 
forms is at best a very difficult one to settle, it has seemed best to 
omit the reported hybrids from this paper. 
BACCHARIS. 
` B. HALIMIFOLIA L. Escaped from cultivation in Cambridge, in 
Brighton, in the Fenway district of Boston, and perhaps elsewhere. 
BAERIA. 
B. GRACILIS Gray, var. TENERRIMA Gray. N. Chelmsford (W. P. 
Alcott, June 4, 1879). Specimen in herb. Peabody Acad. Sci. Adven- 
tive from California. 
B. ULIGINOSA Gray. N. Chelmsford (W. P. Alcott, June 10, 1879). 
Specimen in herb. Peabody Acad. Sci. Adventive from California. 
BELLIS. 
B. PERENNIS L. Escaped from cultivation at Oak Grove, Malden 
(F. S. Collins, May 31, 1886). Specimen in herb. N. E. Botanica: 
Club. 
BIDENS. 
B. artstosa (Michx.) Britton. Dump, Lowell (C. W. Swan, Sept. 
9, 1884); rubbish heap, Botanic Garden, Cambridge (M. L. Fernald, 
1890). 
B. AnisTOsA (Michx.) Britton, var. FRIrcaeyI Fernald. See Rno- 
DORA xv. 74-78, 1913. Made land, S. Boston (C. E. Faxon, August, 
1878). Specimen in herb. Gray. 
B. artstosa (Michx.) Britton, var. mutica (Gray) Gattinger. 
See Ruopora l. ce. Soldiers Field, Brighton (A.S. Pease, Oct. 6, 1903); 
Sharon (S. F. Poole, September, 1905). 
[B. Beckii Torr. is recorded under Megalodonta.| 
B. BIPINNATA L. A rare weed at Lowell, Malden, Boston and 
Dedham. 
