1026 FLORA 



lanceolate, acuminate, mostly tomentose, commonly with several subulate spread- 

 ing ones at the base; rays 12-15, Linear, conspicuous; disk-corollas 5 lobed; 

 achenes glabrous; pappus dull. On sea-beaches and rocks near the sea, Me., 

 N. B. and the lower St. Lawrence to Lab. and the Arctic Sea. Also in Alaska 

 and northern Asia. July-Aug. 



2. Senecio frigidus Less. Arctic Senecio. (I. F. f. 4034.) Perennial, 

 more or less tomentose, or becoming glabrous when old; stem slender. 1.53 dm. 

 high, bearing a solitary head (rarely 2 or 3). Basal and Lower leaves spatulate or 

 obovate, petioled, obtuse, repand-dentate or entire; stemdeaves oblong to linear- 

 lanceolate, obtuse or acute, sessile, mostly entire, smaller; involucre broadly cam- 

 panulate, its bracts lanceolate, acute, with no exterior smaller ones; rays 10-16, 

 12-20 mm. long, 3-toothed, linear-oblong, or cuneate at the base; achenes gla- 

 brous or sparingly pubescent. Lab. and arctic Am. to Alaska. Also in north- 

 eastern Asia. Summer. 



3. Senecio integerrimus Nutt. Entire-leaved Groundsel. (I. F. f. 4035.) 

 Perennial, more or less woolly when young, glabrous or nearly so when old. 

 Leaves entire, or sparingly denticulate, somewhat fleshy, the lower and basal ones 

 oval or oblong, obtuse or obtusish at the apex, 7-15 cm. long, 2-4 cm. wide, peti- 

 oled, the upper linear or lanceolate, acute, the uppermost very small ; heads nu- 

 merous, corymbose, long-peduncled, 12-20 mm. broad; involucre nearly cylindric, 

 its principal bracts linear, green, usually with a few subulate outer ones; rays 8-12, 

 linear-oblong; achenes nearly glabrous. Minn, and Manitoba to Wyo. and Br. 

 Col. June-July. 



4. Senecio atriapiculatus Rydb. Black-tipped Groundsel. (I. F. f. 4036 

 as S. lugens.) Similar to the preceding species, more or less woolly when young, 

 soon glabrous; stem stout, 3-9 dm. high. Basal and lower leaves oblong, oval, 

 or slightly spatulate, obtuse or acute, denticulate or dentate, 5-12 cm. long, 3-4 

 cm. wide, narrowed into margined petioles; upper leaves few, sessile, small and 

 bract-like; heads several or numerous, corymbose, often short-peduncled, 12-20 

 mm. broad; involucre campanulate, its bracts lanceolate or oblong-lanceolate; rays 

 IO -1 2, oblong-linear; achenes glabrous. In moibt soil, the N. W. Terr, to Minn., 

 Iowa and Neb., west to Br. Col. and Cal. June-Aug. This has been confused with 

 the smaller arctic S. lugens Richardson. 



5. Senecio Purshianus Nutt. Pursh's Groundsel. (I. F. f. 4037 as 

 S. canus.) Perennial, densely and persistently white-tomentose to the inflores- 

 cence; stems slender, usually tufted, 1-2 dm. high. Basal and lower leaves spatu- 

 late or oval, entire, very obtuse, 3-6 cm. long, narrowed into petioles; upper leaves 

 oblong or spatulate, obtuse or acute, mostly sessile, smaller, entire; heads several 

 or numerous, 10-15 mm - broad, usually slender-peduncled; involucre campanulate, 

 or at first short-cylindric, about 8 mm. high, its bracts linear-lanceolate, acute 

 sparingly tomentose, or glabrate, usually with no exterior smaller ones; rays 8-12; 

 achenes glabrous, at least below. In dry soil, Manitoba to Minn, and Neb., west 

 to Br. Col. and Utah. May-Aug. It has been confused with the larger S. canus 

 of the Rockies. 



6. Senecio tomentdsus Michx. Woolly Ragweed. Ashwort. (I. F. 

 f. 4038.) Perennial, more or less densely and persistently tomentose or woolly-canes- 

 cent; stems rather stout, solitary, or sometimes tufted, 3-7 dm. high. Basal and 

 lower leaves ovate-lanceolate, oblong or rarely spatidate. erect, very obtuse, 5— 15 

 cm. long, 1-5 cm. wide, narrowed or truncate at the base; stem-leaves few and dis- 

 tant, small, linear-lanceolate or spatulate. crenate or rarely laciniate; heads mostly 

 long-pedancled, 16-20 mm. broad; involucre cylindric, or narrowly campanulate, 

 its bracts linear-lanceolate, acute or acuminate, at length glabrate; rays 10-15; 

 achenes hispidulous, at least on the angles. In moist soil, southern N. J. to Fla., 

 west to La. April June. 



7. Senecio Plattensis Nutt. Prairie Ragwort. (I. F. f. 4039.) Peren- 

 nial; similar to the preceding species, usually smaller-leaved. Lower and less tomen- 

 tose, or becoming glabrate in age. seldom over 4 dm. high. Basal leaves oval, 

 (.vile <.r oblong, some or all of them more or less pinnatifid, with the terminal 

 segment much larger than the lateral ones, crenulate or dentate, loiig-petioled; 



■I or numerous, compactly or loosely corymbose, conspicuously radiate. 

 111. to S. Dak., Wyo., Colo, and Ind. Terr. April-June. 



