COMPOSITE FAMILT. 201 



49. "POTii'UL'NlA, LEAF-CUP. (These coarse and inelegant plants are 

 oddly dedicated to one of the Muses. ) Fl. summer and autumn, y. 



P. Canadensis, common in shaded ravines N., is 3° - 5° high, clammy- 

 hairy, with thin leaves, the lower piunatifid, the upper 3 - 5-lobcd or angled, 

 and the few pale-yellow and broad rays of the small heads shorter than the 

 involucre. 



P. Uvedilia, in rich soil from New York to 111. and S., is roughish-haiiy, 

 stout, 4°- 10° high, with large ovate and angled or lobed leaves, the upper 

 ones sessile, and rays of the pretty large head 10 -15, bright yellow, longer than 

 the involucre. 



50. StiiPHIUM, EOSIN-PLANT. (Ancient Greek name of some very 

 different plant.) Fl. summer and autumn. 5^ 



§ 1 . Leaves alternate, large, most of them petioled. 

 * The stout and rough flowering stems (3° - 6° high) leafy tip to the few large heads : 



scales of involucre ovate, with tapering and spreading rigid tips. 

 S. lacini&tum, Eosin-Weed or Compass-Plakt, of prairies, from Michi- 

 gan W. & S., so caUed because the rough-hairy deeply pinnatifid root-leaves (of 

 ovate outline) incline to present their edges N. & S. 



» » The slender smooth flowering stems (4° - 10° high) leafy only near the base, 



dividing above into a panicle of many smaller Jieads. 

 S. terebinthinkceum, Pkairie-Dock, so called from the appearance 

 of the large root-leaves, which are ovate or heart-oblong and 1° - 2° long, besides 

 the slender petiole, the margins somewhat tootlied : common W. 



S. compositum, from North Carolina S., is more slender and smaller, with 

 round heait-shaped leaves either toothed or cut, or divided. 



§ 2. Leaves or many of them in whorls of 3 or i alpng the terete stems, rather small, 



entire or coarsely toothed. 

 S. trifoli&,tum, of S. & W., has the smooth stem 4° -6° high, lanceolate 

 roughish leavts, and small heads. 



S. AsteriscuSj of dry soil S., is rough-hairy, with fewer and larger heads. 



§ 3. Leaves opposite and clasping or connate : stems leafy to the top. 



S. integrif61ium, in pr.iiries from Michigan W- & S. ; roughish, 2° -4° 

 high, with lancc-ovate partly heart-shaped and entire distinct leaves. 



S. perfoli&tum, Cnp-PLAur, of rich soil W. & S. : with very smooth 

 square stems 4° - 9° high, around which the ovate coarsely toothed leaves are 

 connate into cup which holds water from the rains. 



61. DAHIiIA. (Named for a Swedish professor, Dahl, contemporary with 

 LinnsBus. ) y. Two or three Mexican species, of which the most familiar is 

 D. vari&tailis, Common Dahlia of the gardens, with pinnate leaves, ovate 



serrate leaflets, and large heads, jnuch increased in size and altered, of all colors : 



roots fascicled and tuberous (Lessons, p. 32, fig. 60). 



52. COBEOPSIS, TICKSEED. (Named from Greek word for bug, from 

 the shape of the akenes. ) Many wild species : several cult, for ornament : these 

 are the commonest. Fl. summer. (See Lessons, p. 106, 107, fig. 219, 220.) 



§ 1. Rays broad, coarsely 3 - 5-ioothed : outer involucre not longer than the inner : 

 akenes orbicular or oval, incurved when mature. Chiefly cultivated. 



* ® ® Disk-flowers and lower part of the rays dark-colored or brown-purple : 

 akenes in these specif wingless and nearly naked at top : leaves compound. 



C. tinct6ria, of Arkansas, &c., the commonest Coreopsis or Calliopsis 

 of all country gardens ; smooth, with lower leaves twice-pinnately divided into 

 narrow leaflets, numerous heads, and lower half or sometimes almost the whole 

 of rays brown-purple : in one variety they are changed to tubes. 



