988 FLORA. 



acute; rays 12-20, bright yellow, usually orange at the base; disk depressed- 

 globose, 10-16 mm. broad, brown-purple; chaff of the receptacle acute, ciliate or 

 naked; florets 5.5-6.5 mm. long; achenes 2.5-3 mm. high; pappus a short crown. 

 In moist soil, N. J. to Mich., south to Ala. and Ark. Aug. -Oct. 



11. Rudbeckia Sullivantii Boynton & Beadle. SULLIVANT'S CONE-FLOWER. 

 Perennial, 512 dm. high. Stem-leaves ovate to ovate-lanceolate, the lower 15-20 

 cm. long, 4-8 cm. wide, their petioles 3-7 cm. long, the blade coarsely and irreg- 

 ularly serrate, more or less pubescent; heads several, 5-9 cm. broad; rays 10-15; 

 chaff acute, smooth or nearly so; florets 6.5-7.5 mm. long; achenes 3-4 mm. high. 

 Ohio and Michigan. 



12. Rudbeckia laciniata L. TALL OR GREEN-HEADED CONE-FLOWER. 

 (I. F. f. 3890.) Perennial; much branched, glabrous, or nearly so, 1-3.5 mm - 

 high. Leaves rather thin, minutely pubescent on the margins and upper surface, 

 broad, the basal and lower ones long-petioled, often 3 dm. wide, the segments 

 variously toothed and lobed; stem-leaves shorter-petioled, 3 5-parted or divided, 

 the upper ones much smaller, 3-lobed, dentate or entire; heads several or numer- 

 ous. 6-10 cm. broad; rays 6-10, bright yellow, drooping; bracts of the involucre 

 unequal; chaff of the receptacle truncate and canescent at the apex; pappus a 

 short crown. In moist thickets, Quebec to Manitoba and Mont., south to Fla., 

 Kans. and N. Mex. July-Sept. 



Rudbeckia laciniita humilis A. Gray. Simple or branched, glabrous or nearly so, 

 3-6 dm. high, some or all of the basal leaves orbicular and undivided ; heads 4-6 cm, broad; 

 disk globose ov ovoid. Va. and N. C. to Tenn. and Ga., mostly in the mountains. 



13. Rudbeckia amplexicaulis Vahl. CLASPING-LEAVED CONE-FLOWER. 

 (I. F. f. 3891.) Annual; glabrous throughout, somewhat glaucous; stem branched, 

 grooved, 3-6 dm. high, the branches ascending. Leaves entire, or sparingly 

 toothed, i-ribbed, reticulate-veined, the lower oblong to spatulate, sessile, the 

 upper ovate, ovate-oblong, or lanceolate, acute ; heads solitary at the ends of the 

 branches, long-peduncled, about 5 cm. broad; bracts of the involucre few, lance- 

 olate, acuminate; rays yellow, or sometimes brown at the base; disk ovoid- oblong, 

 often becoming 25 mm. high ; achenes striate and transversely wrinkled, obliquely 

 attached to the elongated receptacle; chaff at length deciduous ; pappus none. In 

 wet soil, Kans. and Mo. to La. and Tex. June-Aug. 



61. RATIBIDA Raf. 



Mostly 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 Concave 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. Achenes short, flat- 

 tened, sharp-margined, or winged, at length deciduous with the chaff. Pappus 

 with i or 2 teeth, or none. [Name unexplained. ] About 4 species, of N. Am. 



Style-tips lanceolate-subulate ; leaf-segments lanceolate ; rays 25-75 mm - Ion?. 



1. R.ptnnata. 

 Style-tips short, blunt ; leaf-segments linear ; rays 6-30 mm. long. 



Disk cylindric, at length 2.5 cm. long or more ; rays mostly equalling it, or longer. 



2. R. columnaris. 

 Disk globose to short-oval, about i cm. high; rays mostly short. 3. R. Tagetes. 



I. Ratibida pinnata (Vent.) Barnhart. GRAY- HEADED CONE-FLOWER. 

 (I.F.f.3892.) Perennial; rough and strigose-pubescent throughout; stem branched 

 or simple, 9-15 dm. high. Leaves pinnately 3~7-divided, the basal ones sometimes 

 2.5 dm. long, petioled, the segments cleft or entire, acute or acuminate; upper leaves 

 sessile or nearly so, the uppermost commonly small and entire; bracts of the in- 

 volucre linear or linear-oblong, short, reflexed; rays 4-10, bright yellow, drooping; 

 disk oblong, gray or becoming brown, rounded, at length twice as long as thick; 

 the inner margin of achenes produced into a short tooth. On dry prairies western 

 N. Y. to Fla., west to S. Dak., Neb. and La. June-Sept. 



