476 



COMPOSITAE (COMPOSITE FAMILY) 



NODDING BUR MARIGOLD 

 Bldens cernua, L. 



Other English names : Double-tooth, Water Agrimony. 



Native. Annual. Propagates by seeds. 



Time of bloom: July to October. 



Seed-time: August to November. 



Range: Nova Scotia to British Columbia, southward to the Caro- 



linas, Missouri, and California ; also in Europe and Asia. 

 Habitat: Marshy meadows, swamps, and along streams. 



This species, usually in company with the similar, but larger, 

 BROOK SUNFLOWER (BUens laevis, B.S.P.), often covers acres of 

 lowlands with yellow bloom, to be suc- 

 ceeded by the clutching brown fruits. It 

 is small, six to thirty inches high, pale 

 green, smooth, or sometimes slightly 

 rough-hairy, rather stout, with short 

 branches. Leaves opposite, narrowly 

 lance-shaped, sessile, often joined at base, 

 edged with coarse, distant, and unequal 

 teeth. Heads numerous, large, broader 

 than their height, the peduncles short and 

 at first erect but drooping after fertiliza- 

 tion; rays often lacking, but, when pres- 

 ent, bright yellow, exceeding the length 

 of the disk by about one-half ; disk-florets 

 orange-yellow, five-lobed ; outer bracts of 

 the involucre longer than the head, usually 

 bristle-fringed and spreading; the inner 

 row short, ovate, pointed, with yellowish, 

 scarious margins. Achenes wedge-shaped, 

 FIG. 330. Nodding Bur dull brown, four-angled, four-awned, an- 

 Marigold (Bidens cernua). g } es an( j awns barbed downward, causing 

 these fruits to be even more readily at- 

 tached to clothing and the coats of animals than those of the 

 preceding species. (Fig. 330.) 



' The same measures for suppression are necessary as for the 

 Swamp Beggar-tick. 



