COMPOSITAE (COMPOSITE FAMILY) ATT 
SPANISH NEEDLES 
. 
Bidens bipinnata, L. 
Native. Annual. Propagates by seeds. 
Time of bloom: July to October. 
Seed-time: August to November. 
Range: Rhode Island to Nebraska and Arizona, southward to 
Florida and Mexico. Also in Europe and Asia. ‘ 
Habitat: Gardens, fields, roadsides, and waste places. 
Satisfied if the soil is only moderately moist, this weed often 
makes itself troublesome in fields of Indian corn and other cultivated 
crops, maturing seeds after the horse- 
hoe culture has ceased. Stems slender 
with many spreading branches, one to 
five feet tall, erect, smooth, and four- 
sided. Leaves pinnately twice or thrice 
divided, the segments broadly lance- 
shaped, deeply cut and toothed, op- 
posite or the uppermost sometimes al- 
ternate; petioles slender and grooved. 
Heads usually numerous, on long, ridged, 
and angular peduncles; outer bracts 
of the involucre linear, shorter than 
the inner ones which are broader and 
acutely pointed; rays small and few, 
pale yellow with dark veins; disk-florets 
yellow and five-lobed. Achenes brown, 
nearly three-fourths of an inch long, 
slim, spindle-shaped, four-angled, usu- 
ally tipped with four rather short, awl- 
like, diverging awns, barbed downward. 
(Fig. 331.) 
Fic. 331.—Spanish Needles 
(Bidens bipinnata). X i. 
Means of control cl , 
Prevent seed production, continuing the tillage of cultivated 
crops late or hand-pulling the late-flowering remnant of the weed 
growth. All waste-land plants should be cut several times during 
the growing season. 2 
