COMPOSITE FAMILY. 193 



1 . S. vulga'ris, L. Leaves piunatifid and dentate, the lowest petiolate, 

 the upper clasping ; heads nodding. 



COMMON SENECIO. Groundsel. 



Stem 6-12 inches high, paniculately branching, angular, mostly smoothish. Leaves 

 1-3 inches long, the upper ones somewhat auricled and clasping, the lower ones on 

 petioles ^ an inch to an inch in length. Involucre somewhat obconical, smooth ; scales 

 often sphacelate, or blackish at apex, bracteolate at base. Akenes pubescent on the ribs. 



Obs. A homely little weed in waste grounds from New Engand to 

 Pennsylvania. DE CANDOLLE says that it has migrated almost every- 

 where with European men ; but whether it is likely to become trouble- 

 some to our farmers is not yet ascertained. 



** Heads radiate, corymbose ; root perennial. 



2. S, au'reus, L. Smooth, or often somewhat arachnoid-woolly when 

 young ; radical leaves roundish-ovate and subcordate, or varying to 

 obovate and oblong-lanceolate, crenate-serrate, petiolate ; lower stem- 

 leaves lyrate the upper ones lanceolate, pinnatifid, sessile or partly 

 clasping ; corymb subumbellate. 



GOLDEN SENECIO. Golden Ragwort. Squaw-weed. 



Stem 1-2 feet high, corymbosely branched, the lower branches elongated, axillary 

 ami distant the upper ones crowded or subumbellate at the summit of the stem. Leaves 

 1-3 inches long, varying in form on the different varieties ; petioles of the radical leaves 

 1 or 2 - 6 or 8 inches long. Heads terminal on the fastigiate branches ; rays and disk yel- 

 low. Akenes linear-oblong, striate-ribbed pappus white. 



Banks of streams, moist sterile Holds, and meadows : throughout the United States. 

 Fl. April -June. Fr. June -July. 



Obs. A very variable plant, some forms of which have been described as 

 species. The principal varieties are, var. obovatus, with round-obovate 

 root-leaves ; this usually grows in dryer places than the var. Balsamitse, 

 which has the root-leaves oblong, spatulate, or lanceolate, sometimes 

 cut-toothed, tapering into the petiole. The last named variety is a fre- 

 quent weed in poor moist meadows and pastures, where the farmer may 

 often see patches, in the spring, made conspicuous by its yellow rays. 

 The var. obovatus (called " Squaw-weed") has been denounced, by an 

 Agricultural writer in New York, as being poisonous to sheep ; but I 

 know not how correctly, and am rather inclined to doubt the accuracy 

 of the statement. The Senecios are a multitudinous family. Prof. DE 

 CANDOLLE describes nearly 600 species of which about 40 are enume- 

 rated by TORREY & GRAY as inhabitants of North America. Although 

 the species are so numerous, and, I believe, altogether worthless, I do not 

 know that they have been found very troublesome on the farm. 



23. CENTAURE'A, L. STAR-THISTLE. 



[From the Centaur, Chiron, who, it is said, cured his wound with the plant.] 



Heads many-flowered; florets unequal, the marginal ones larger and 

 neutral, or sometimes wanting, the central ones perfect. Involucre 

 roundish ovoid, the scales variously margined or appendaged. Receptacle 

 bristly. Akenes compressed. Pappus usually composed of scabrous fili- 

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