CICHOKIA CEA E. 899 



sessile or sagittate-clasping, 7-15 cm. long, 1-3 cm. wide, the basal and lower ones 

 petioled; heads commonly very numerous, 4-8 mm. broad; involucre cylindric, 

 10-14 mm. high, the outer bracts shorter than the inner; rays yellow or reddish. 

 In dry, open soil, N. B. and Ont. to Idaho, Ga. and Kans. July- Sept. 



7. Lactuca Steelei Britton, n. sp. Steele's Wild Lettuce. Stem and 

 branches hirsute. Leaves obovate to oval, the larger 2 dm. long and 1 dm. wide, 

 sessile, irregularly dentate, not lobed, hispid on the veins beneath, short-acumi- 

 nate; involucre about 12 mm. high; rays not seen; achenes oval, 3 -ribbed, about 

 3 mm. long, the filiform beak slightly shorter; pappus bright white. Near Wash- 

 ington, D. C, E. S. Steele, July 10, 1897. 



8. Lactuca pulchella (Pursh) DC. Large-flowered Blue Lettuce. 

 (I. F. f. 3542.) Perennial, glabrous throughout, somewhat glaucous; stem rather 

 slender, leafy up to the corymbose- paniculate inflorescence, 3-9 dm. high. Leaves 

 linear-lanceolate, lanceolate or oblong, acute, entire, dentate, lobed or pinnatifid, 

 those of the stem sessile or partly clasping, 5-20 cm. long, 4-35 mm. wide, the 

 lowest and basal ones sometimes petioled; heads mostly numerous, 12-20 mm. 

 broad; involucre well imbricated, 16-20 mm. high ; achenes oblong-lanceolate, 

 flat, twice as long as their tapering beaks. In moist soil, western Ont. to the 

 N. W. Terr, and Br. Col., south to Mich., Kans., N. Mex. and Cal. June-Sept. 



9. Lactuca villosajacq. Hairy-veined Blue Lettuce. (I. F. f. 3543.) An- 

 nual or biennial; stem glabrous, leafy up to the paniculate inflorescence, 6-18 dm. 

 high. Leaves acuminate, acutely dentate or the teeth mucronate-tipped, glabrous 

 above, pubescent with short, stiff hairs on the veins beneath, sessile and slightly 

 clasping at the base, or petioled, 10-15 cm - l° n g> 3~6 cm. wide, the lowest some- 

 times lobed at the base; heads numerous, 6-10 mm. broad; involucre about I cm. 

 high, some or all of the bracts obtuse; achenes thick, oblong, little flattened, nar- 

 rowed above. In thickets, N. Y. to 111., south to Fla., Ga. and Ky. July-Sept. 



10. Lactuca Floridana (L.) Gaertn, False or Florida Lettuce. (I. F. 

 f. 3544.) Annual or biennial; stem glabrous, rather stout, leafy up to the large, 

 paniculate inflorescence, 1-2 m. high. Leaves sessile or petioled, 1-3 dm. long, 

 glabrous above, pubescent on the veins beneath, the lateral segments lanceolate to 

 oval, acute, all usually dentate, or the leaves irregularly lobed ; heads numerous, 

 6-10 mm. broad; rays blue; involucre about 12 mm. high. In moist, open places, 

 southern N. Y. and Penn. to 111., Neb., Fla., La. and Kans. July-Sept. 



11. Lactuca spicata (Lam.) Ffitchc. Tall Blue Lettuce. (I. F. 

 f. 3545.) Annual or biennial; stem usually stout, glabrous, 1-3.5 m - higli, leafy 

 up to the large, rather dense panicle. Leaves deeply pinnatifid or lobed, sharply 

 dentate with mucronate-pointed teeth, sessile, or the lower narrowed into margined 

 petioles, glabrous on both sides, or pubescent on the veins beneath, 12-30 cm. long, 

 5-15 cm. wide; heads very numerous, about 4 mm. broad; rays blue to nearly 

 white; achenes oblong, compressed, narrowed above into a short neck. In moist 

 soil. Newf. to Manitoba, south to N. Car., Tenn., Iowa and S. Dak. July-Oct. 



Lactuca spicata integrifolia (A. Gray) Britton. Leaves oblong, sharply denticulate, 

 undivided, or some of the lower ones pinnatifid. N. Car. to Mich. 



16. LYGODESMIA D. Don. 



Glabrous rigid branching herbs, with linear leaves, or the basal and lower ones 

 sometimes broader and pinnatifid, those of the stem very narrow and entire or 

 reduced to linear scales, and middle-sized 3-12-flowered heads of pink or purple 

 flowers, solitary and erect at the ends of the stem and branches, or sometimes race- 

 mose. Involucre cylindric, its principal bracts 5-8, linear, scarious-margined, 

 equal, slightlv united at the base, with several very short outer ones. Receptacle 

 flat, naked. Rays truncate and 5-toothed at the apex. Anthers sagittate at the 

 base. Style-branches slender. Achenes linear, smooth or striate. Pappus of 

 copious somewhat unequal simple bristles. [Greek, twig-bundle, from the numer- 

 ous branches.] About 6 species, natives of western and southern N. A. 

 Heads solitary at the ends of the branches; leaves linear or subulate. 1. L. juncea. 

 Heads racemose along the branches ; leaves elongated-linear. 2. L. rostrata. 



I. Lygodesmia juncea (Pursh) D. Don. Rush-like Lygodesmia. (I. F. 

 f. 3546.) Perennial by a thick woody root; stems stiff, striate, much branched, 



