410 Wiegand: Some Species oe I^idens 



and without doubt se\'cral species are now aggregated under one 

 name. A simple-leaved pale form from central Europe with often 

 only 3 awns and large foliaceous involucre is difficult to distinguish 

 from some forms of B, coniosa, and is probably the B. tripartita 

 intcgra of Koch. Another simple-leaved form with small heads and 

 corky-thickened 2-awned achenes from southern Europe and Asia 

 is /?. tripartita tenuis DC. A third form with comose often cernuous 

 heads, incised sessile leaves and two awns connects this species 

 with B, ccrnua and has been separated as B. platyccpliala Oersted. 

 B. tripartita is found throughout Europe, Asia and Japan, but 

 so far has not been found in North America (Addison Brown re- 

 ported it as a ballast plant at Hunter's Point in the vicinity of New 



I 



York City, Bull. Torr. Bot. Club, i6 : 357. i^^79). 



5. BiDENs COMOSA (A. Gray) Wiegand, Bull. Torr. Bot. Club, 24: 



436. 1897. 



B. connata DC. Prod.; T. & G. El. N. A.; Torr. Fl. N. U. S. 



in part); Dark Fl. Cest. 



B. connata comosa A. Gray Man. 261. 1867 [ed. 5]. 



Pale throughout : stem stout, erect (30-80 cm.), glabrous, 

 stramineous or sometimes reddish, internodes rather short ; branches 

 short, spreading : leaves undivided (8 cm. long), pale grecn^ nar- 

 rowly elliptic or elliptic-lanceolate, acute, attenuate at the base into 

 a short strongly margined petiole, serrate with rather small regular 

 teeth (rarely coarser ones, and the upper nearly entire): heads not 

 numerous, large (12 mm. high x 12-18 mm. broad) nearly globu- 

 lar or broader, on short stout peduncles thus often appearing clus- 

 tered, erect ; outer involucral bracts 6-8, linear or linear-lanceolate, 

 mucronate, usually entire, very large, conspicuous and unequal, 2-5 

 times the length of the disk (30-50 mm. Ipng), nearly erect ; inner 

 bracts oblong-ovate to ovate-lanceolate, acutish, stramineous, about 

 8 in number : ray flowers wanting : corolla of the disk flowers 

 large (5 mm.), narrow funnelform, pale yellow, 4-toothcd, gradu- 

 ally contracted into a basal portion which is longer than the upper, 

 equaling the awns : stamens and style included : mature achenes 

 large and flat (8-10 mm. x 3 mm.) scarcely carinate, cuneate with a 

 broad base, slightl}' contracted at the summit, dark olive-green or 

 brownish, not papillose and glabrous or nearly so, often dark- 

 punctate, margins strongly retrorsely barbed, summit convex ; awns 

 3, long and conspicuous (two long ones ^-^ length of achene, 

 third shorter, rarely a fourth very minute), erect, retrorsely barbed. 



