RuDBECKiA. COMPOSITE. 307 



91. RU.DBECKIA. Linn. (excl. spec.) ; Gferf.n. fr. t. 172 ; Cass. ; DC. 



Heads many-flowered; the ray-flowers neutral, in a single series; those 

 of the disk tubular, perfect. Scales of the involucre foliaceous, in about 2 

 series, spreading. Receptacle conical or often more or less elongated and 

 spiciform ; the chaff" concave or navicular. Corolla with a cylindraceous or 

 somewhat dilated throat ; the teeth erect or spreading. Branches of the style 

 terminated by a very short obtuse cone, or rarely with a subulate-lanceolate 

 barbellate appendage. Achenium quadrangular, obpyramidal or prismatic, 

 glabrous, flat at the summit. Pajipus none, or minute and coroniform, 

 rarely somewhat conspicuous. — Mostly perennial (North American) herbs, 

 with alternate leaves, and rather large and showy heads terminating the stem 

 or branches. Rays yellow (rarely par(icolored), usually elongated, spread- 

 ing or drooping. Corolla of the disk, and tlie style, purple or brownish-pur- 

 ple, sometimes greenish-yellow. Anthers fuscous. 



§ 1 . Disk conical or suh globose : pappus very short and coroniform, or often 

 none. — Rudbeckia proper. (Centrocarpha, Don, partly.) 



* Disk (kirk purplish-brovm, subghbose or broadly corneal : appendages of the style laiv- 

 ceolate or broadly subulate. 



1. R. hicolor (Nutt.) : annual, hirsute; stem mostly simple, naked at the 

 summit ; leaves oblong, sessile, obscurely serrate, rather obtuse ; the lower- 

 most petioled ; head (rather small) solitary; scales of the involucre linear- 

 oblong, hispid, rather shorter than the oblong (yellow and brownish-purple) 

 particolored rays ; disk conical ; chaff" of the receptacle rather acute, hirsute 

 at the summit, as long as the corolla ; pappus none. — Null.! in jour. acad. 

 Philad. 7. p. 81. 



Arkansas and on Red River, Nuttall ! Texas, Drummond ! — Stem 1-2 

 feet high. Rays about 10, half an inch long; the lower half "intense black- 

 ish bro'wn, with the gloss of velvet" {Nutt.) or dark purple; the upper part 

 yellow. Branches of the style lanceolate, barbellate. 



2. R. hirta {Linn.) : very hirsute or hispid throughout; stems simple or 

 slightly branched, naked at the summit ; radical and lowest cauline leaves 

 spatulate-oval or oblong, triplinerved, denticulate, petioled ; the upper ovate- 

 oblong or lanceolate, sessile, denticulate or serrate; scales of the involucre 

 numerous, narrowly lanceolate; rays (about 14) spreading; disk broadly 

 conical ; chaff" of the receptacle linear, mostly acute, hairy at the summit, 

 about the length of the corolla ; pappus obsolete. — Linn. ! spec. 2. p. 907 ; 

 Michx. ! fl. 2. p. 143 ,• Pursh ! I. c. ; Brit. fl. gard. 1. t. 82 ; Ell. I. c. ; 

 Darlingt.fl. Cest. p. 480 ; DC! prodr. 5. p. 556. R. serotina, Nutt. ! in 

 jour. acad. Pliilad. 7. p. 80. 



a. heads large ; rays nearly twice the length of the involucre. — Obelis- 

 cotheca integrifolia &c.. Dill. Eltli. t. 218, f 285. 



(3. heads smaller ; rays scarcely exceeding the involucre ; leaves mostly 

 narrow. — R. strigosa Nutt.! in trans. Amer. ])ltil. soc. I. c. 



Dry soil. Upper Canada! and Western part of the State of New York! 

 Michigan! &c. to Florida! Western Louisiana! and Texas! (5) or K ? 

 July-Sept.— Stem 1-2 or 3 feet high, very rough. Rays bright yellow, 



