1304 _CARDUACEAE 
9. Senecio rotündus (Britton) Small. Perennial, glabrate. Stems 3-6 dm. tall, 
corymbose above: leaves mainly basal; blades suborbicular to orbicular-ovate, 3-7 cm. in 
diameter, coarsely crenate-serrate, truncate at the base, decurrent into the margined peti- 
oles, these as long as the blades or longer: heads in open corymbs: involucres 4-5 mm. 
high ; bracts linear-subulate, 5 mm. long, acute: ligules of the ray-flowers light yellow, 
linear, about 8-10 mm. long: achenes 2.5 mm. long. [S. obovatus rotundus Britton. ] 
In low grounds or on wet rocks, Ohio to Missouri, Louisiana and Texas. Spring. 
10. Senecio obovàtus Muhl. Perennial, nearly glabrous. Stems solitary or loosely 
clustered, 1-5 dm. tall, corymbose above: leaves mainly basal or near the base of the stem; 
blades spatulate to obovate, 2-10 cm. long, rounded at the apex, coarsely toothed or partly 
lyrate-pinnatifid, narrowed into broad petioles : stem-leaves with pinnatifid blades : heads 
in open corymbs: involucres 4-5 mm. high; bracts narrowly linear or subulate-linear: 
ligules of the ray-flowers deep yellow, 5-7 mm. long: achenes 3-5 mm. long. 
In moist soil, Nova Scotia to Ontario, Michigan, Florida and North Caroiina. Spring. 
11. Senecio Purshiànus Nutt. Perennial, densely and persistently grayish white 
tomentose to the involucres. Stems usually tufted, 1-2 dm. tall: leaves mostly crowded on 
the caudex-like rootstocks, these mainly basal ; blades spatulate, 3-6 cm. long, entire, ob- 
tuse, narrowed into slender petiole-like bases: heads solitary or few, showy : involucres 
6-8 mm. high ; bracts narrowly linear, merely cobwebby in age: ligules of the ray-flowers 
oblong or oval-oblong, 5-7 mm. long: achenes 3 mm. long, glabrous. 
In dry soil, Manitoba to British Columbia, Minnesota, Texas and Utah. Spring and summer. 
12. Senecio Balsámitae Muhl. Perennial, densely and often permanently woolly 
at the base of the stem and about its nodes. Stems solitary or tufted, 2-6 dm. tall, some- 
times sparingly branched above: leaves mainly basal; blades oblong to oblong-spatulate, 
2-5 cm. long, toothed, sometimes with a few more salient teeth near the base; petioles 
commonly longer than the blades: stem-leaves 1-2-pinnatifid: heads in rather close cor- 
ymbs: involucres 4-5 mm. high ; bracts narrowly linear, becoming glabrous: ligules of 
the ray-flowers 4-5 mm. long: achenes about 2 mm. long, hispidulous. : 
In stony or dry soil, Nova Scotia to British Columbia, North Carolina and, Texas. Spring and 
early summer. 
13. Senecio Eàrlei Small. Perennial, bright green, densely cottony below, spar- 
ingly so and glabrate above. Stems usually tufted, 2-5 dm. tall, corymbosely branched 
above: leaves various, the basal quite numerous: blades oval or oblong, 1.5-6 cm. long, 
serrate, obtuse or retuse, often crimson beneath ; petioles longer than the blades: stem- 
leaves with pinnatifid linear-lanceolate or oblong blades, the upper sessile: peduncles 
slender : involucres hemispheric, 8-9 mm. broad, 8-10 mm. high ; bracts linear or nearly 
80, 5-5.5 mm. long, acute, hyaline-margined : rays oblong, 4-6 mm. long, bright yellow: 
style glabrous: achenes 3 mm. long, scabro-pubescent on the angles. 
In dry soil, Tennessee and Alabama. Spring and summer. 
14. Senecio Smállii Britton. Perennial, woolly, permanently so below. Stems 
usually tufted, 3-6 dm. tall, corymbose above : leaves mainly basal or near the base of the 
stem ; blades narrowly oblong, linear-oblong or linear-lanceolate, 5-10 cm. long, finely 
toothed or pinnatifid near the base, as long as the petioles or shorter; stem leaves similar 
to the basal or wholly pinnatifid, short-petioled or sessile: heads small, usually conspicu- 
ous by their great number: involucres fully 6 mm. high ; bracts narrowly linear, acumi- 
nate : receptacle about 3 mm. broad: ligules of the ray-flowers 4-6 mm. long: achenes 
1.5-2 mm. long, hispidulous. 3 
In dry soi] and meadows, Virginia to Tennessee, middle Georgia and Mississippi. Spring. 
15. Senecio Platténsis Nutt. Perennial, the stem and leaves persistently woolly. 
Stems 2-4.5 dm. tall, corymbose above: leaves mainly basal ; blades oblong, ovate-oblong 
or ovate, 2.5-4.5 em. long, some or all of them pinnatifid or lyrate-pinnatifid, the terminal 
segments toothed : heads showy : involucre 6.5-7.5 mm. high; bracts linear, usually cob- 
webby : ligules of the ray-flowers bright yellow, broadly oblong, 5-8 mm. long: achenes 2 
mm. long. 
In dry soil, South Dakota and Wyoming to Illinois, Texas and Colorado. Spring. 
16. Senecio tomentdsus Michx. Perennial, more or less densely pale tomentose. 
Stems 2-7 dm. tall, corymbose above: leaves mainly basal; blades oblong or oblong- 
lanceolate, 3415 cm. long, usually obtuse, crenate to nearly entire; petioles longer than 
the blades: stem-leaves few, rarely pinnatifid, the upper sessile and partly clasping: hea 8 
at first clustered : involucres 7-8 mm. high ; bracts narrowly linear-lanceolate, acuminate; 
becoming glabrous, or nearly so : ligules of the ray-flowers deep yellow, 7-9 mm. long : 
achenes nearly 2.5 mm. long. 
In sandy soil, New Jersey to Florida, Arkansas and Texas. Spring, 
