WEEDS OF THE THISTLE FAMILY. 



161 



another page. 



All have the top of the achenes or seeds armed with 

 strongly barbed bristles or awns 

 by which they readily adhere to 

 clothing, wool or hair of animals 

 and thus are widely scattered. 

 The awns are usually 2 in num- 

 ber, whence the generic name Bi- 

 dens, meaning two-toothed. A 

 closely allied species is the com- 

 mon beggar-ticks (B. frondosa 

 L., Fig. 119), which is also very 

 common in moist soil in fence 

 corners, gardens, corn fields and 

 waste places. It has the leaves 

 3-5 divided, the outer bracts 

 larger and achenes wider with 

 more slender awns. The juices 

 sometimes cause an itching or 

 skin irritation when the plant is 

 Fi g . 119. (After vasey) handled. Both can be easily de- 



stroyed by mowing before the seeds ripen, thorough cultivation or 

 improved drainage. 



(A. N. 2.) 



12G. BIDENS BIPINNATA L. Spanish Needles. 



Stem erect, 4-sided, branched, 1-5 feet 

 high; leaves stalked, 1-3 times divided into 

 oblong toothed or lobed segments. Heads 

 numerous, long-stalked; involucre narrow, 

 its bracts linear, the inner ones the larger; 

 flowers few, dull yellow; rays none or 3-4, 

 short, yellow. Achenes linear, 4-sided, f 

 inch long, narrowed upward into a beak 

 which bears 3 or 4 short downwardly barbed 

 awns. (Fig. 120.) 



Common in gardens, cultivated fields, 

 borders of thickets and waste places, es- 

 pecially in rich moist soil. July-Oct. 

 Remedies: pulling or mowing before 



,, , . , _, . Fig. 120. Long inner fruit with barbed 



the Seeds ripen; burning OVer Stubble awns; shorter and thicker outer fruit. 



fields and waste places in autumn. (After Britton and Brown J 



127, 



Foetid Marigold. Yellow Dog-fennel. (A. 



BCEBERA PAPPOSA Vent. 



N. 2.) 



Erect, glandular, strong-scented, very leafy, much branched, 6-18 

 inches high; leaves opposite, sessile, divided into linear bristle-toothed or 



