GENUS 61. 



THISTLE FAMILY. 



473 



10. Rudbeckia laciniata L. Tall, or Green- 

 headed Cone-flower. Fig. 4451. 



Rudbeckia laciniata L. Sp. PI. 906. 1753. 



Perennial ; stem much branched, glabrous, or nearly 

 so, 3-i2 high. Leaves rather thin, minutely pubes- 

 cent on the margins and upper surface, broad, the 

 basal and lower ones long-petioled, often i wide, 

 pinnately 3-7-divided, the segments variously toothed 

 and lobed ; stem leaves shorter-petioled, 3~5-parted 

 or divided, the uppermost much smaller, 3-lobed, 

 dentate or entire; heads several or numerous, 2^-4' 

 broad; rays 6-10, bright yellow, drooping; bracts of 

 the involucre unequal; chaff of the receptacle trun- 

 cate and canescent at the apex ; disk greenish-yellow, 

 at length oblong and twice as long as thick or longer ; 

 pappus a short crown. 



In moist thickets, Quebec to Manitoba, Idaho, Colo- 

 rado, Florida and Arizona. Thimble-weed. A double- 

 flowered form in cultivation is called golden-glow. July- 

 Sept. 



A southern mountain race, lower, often only i high, 

 with smaller heads, has been described as Rudbeckia 

 laciniata humilis A. Gray. 



62. DRACOPIS Cass. Diet. Sci. Nat. 35 : 273. 1825.46:400. 1827. 



An annual caulescent herb, with smooth and glaucous foliage, and alternate broad thickish. 

 entire or slightly serrate, i-ribbed, clasping leaves. Heads radiate, showy. Involucre flat, 

 many-flowered, of few narrow, somewhat foliaceous bracts. Receptacle slender, with early 

 deciduous chaffy scales. Ray-flowers few, neutral, the rays yellow or often brownish-purple 

 at the base. Disk-flowers perfect, fertile, brownish, their corollas 5-lobed. Style-branches 

 with small pubescent appendages. Achenes terete or nearly so, not angled, stnate and 

 minutely transversely wrinkled. Pappus wanting. [Greek, dragon-like, referring to the 

 appendaged style-branches.] 



A monotypic genus of the southeastern United States. 



i. Dracopis amplexicaulis (Vahl) Cass. 

 Clasping-leaved Cone-flower. Fig. 4452. 



Rudbeckia amplexicaulis Vahl, Act. Havn. 2 : 29. fl. 4. 



1783- 

 Dracopis amplexicaulis Cass.; DC. Prodr. 5: 558. 1836. 



Annual ; glabrous throughout, somewhat glaucous ; 

 stem branched, grooved, i-2 high, the branches 

 ascending. Leaves entire or sparingly toothed, i -ribbed, 

 reticulate-veined, the lower oblong to spatulate, ses- 

 sile, the upper ovate, ovate-oblong, or lanceolate, 

 acute, cordate-clasping; heads solitary at the ends of 

 the branches, long-peduncled, about 2' broad ; bracts 

 of the involucre few, lanceolate, acuminate; rays 

 yellow, or sometimes brown at the base ; disk ovoid- 

 oblong, often becoming i' high; achenes not angled, 

 obliquely attached to the elongated receptacle; chaff 

 at length deciduous. 



In wet soil, Missouri to Oklahoma, Louisiana and 

 Texas. June-Aug. 



63. RATIBIDA Raf. Am. Month. Mag. 2 : 268. 1818. 

 [LEPACHYS Raf Journ. Phys. 89: 100. 1819.] 



Perennial herbs, with alternate pinnately divided or parted leaves, and long-peduncled 

 terminal heads of tubular and radiate flowers, the disk-flowers gray or yellow, becoming 

 brown, the rays yellow, or with brown bases, drooping or spreading. Involucral bracts in 

 2 or 3 series. Disk globose, oblong or cylindric. Receptacle columnar to subulate, the con- 

 cave chaff subtending or enveloping the disk-flowers, truncate, the tips inflexed, canescent. 

 Ray-flowers neutral. Disk-flowers perfect, fertile, their corollas with scarcely any tube. 



