48G Nelson: New Plants from Wyoming 



r 



broadly caiiipanulatc, its bracts in about tliree series, some of them 

 dark or purplish-tipped, scarious-margnicd, Hncar-lanceolate, sub- 

 acute, the Innermost slightly acuminate : |Vappus of 12-18 sub- 

 equal bristles all deciduous together in a ring, 2—3 times, as long 

 as the akcnc : receptacle apparently naked : akcnes linear-colum- 

 nar, about 3 mm. long, the 15 striae subequal, minutely denticulate 

 around the summit. 



I 



■ 



Probably most nearly allied to Af. soncJioides T, & G. but the 

 two plants when seen side by side present a very different appear- 

 ance. The dentate rachis and lobes of the leaves, the dentate 

 butcr involucral bracts, the unequally striate akencs and double 

 pappus of J/ soiichoidcs arc marks easily distinguishing it from M. 



* 



runci/iala, 



* 



It occurs on dry, sandy slopes, mostly in the protection of the 

 undershrub. Green River, June 15, 1898, no. 4727; Fort Steele, 

 June 18, 1898, no. 4819. 



¥ 4 



Lactuca sylvatica 



' ' 



. Perennial from rootstocks : stem slender, leafy, the internodes 

 gradually shorter upward, glabrous : leaves entire, oblong-lanceo- 

 late, the lower tapering into a margined petiole, the upper sessile, 

 thin and wholly glabrous, the largest lO— 14 cm. long and 2—'^ 

 cm. wide, gradually smaller upward (the uppermost scarcely more 

 than bracts): panicle rather close, of 10-20 heads, its branches 

 more or less short-bracteate : heads 2 cm. high, about 15-flow- 

 ered : the involucral bracts in about 4 series ; the outer short, 

 ovate ; the inner linear-lanceolate : flowers blue or lilac : akenes ^ 

 mm. long, lanceolate-oblong, distinctly margined and con- 

 spicuously beaked, 4-nerved on each side : the beak nearly half 

 as long as the body of the akene. 



Probably to be associated with Lactuca pnlcluila but differing 



in its entire leaves and margined akenes. The larger akene, longer 



be^ik and its broadly expanded summit are also at variance with 



that. 



Collected at Elk Mountain on Medicine Bow River in the 

 copses on the bank, August 1897, no. 4257. 



Crepis riparia 



Tap-root semi-fleshy, comparatively small, mostly less than i 

 dm. long; stems one or more, 2-4 dm. high, subscapose (linear, 

 bract-like leaves at the base of the lower branches of the panicle 



