larly 3-toothed terminally; disk flowers numerous, perfect, fertile, the corolla 

 yellow and 5-toothed; achenes somewhat laterally compressed but not flat (elliptic 

 in transection and with 2 rounded edges), blackish; pappus absent or rarely of 

 one or two awns. S. repens (Walt.) Michx. 



Local in mud along streams, bayous, lakes, ditches, etc., in Okla. (McCurtain 

 Co.) and s.e., e. and n.-cen. Tex., late summer-fall. 



The var. repens occurs in s.e. U.S., other varieties occur in North America and 

 South America. 



27. Rudbeckia L. Brown-eyed Susan. Cone-flower 



Perennial or annual herbs; leaves alternate (the extreme basal ones sometimes 

 opposite); involucre hemispheric; phyllaries imbricated in 2 or more series; re- 

 ceptacle conical, chaffy throughout, the pales acute; ray flowers present, infertile 

 (styles absent); rays yellow or with a brown spot basally, rarely slightly reddish all 

 over, never white, vaguely 3-toothed apically; disk flowers numerous, perfect, 

 fertile, the corolla tubular, equally 5-toothed terminally and brown (at least 

 terminally), the style branches with blunt or subulate pubescent tips; achenes 

 truncate apically, 4-angled; pappus when present merely a toothed crown of 2 

 to 4 short teeth. 



An American genus of perhaps 30 species. 



1. Achenes with 4 nearly equal facets which are flat or convex, commonly ex- 

 panded by the mature ovules, typically truncate basally and basally 

 attached to the receptacle; pales of the receptacle characteristically 

 1 .5 to 2 times as long as the achenes (2) 



1. Not as above (3) 



2(1). Style branches apically elongate, slenderly subulate 1. R. hirta. 



2. Style branches short and blunt 2. R. fulgida. 



3(1). Leaf blades entire or merely toothed 5. R. maxima. 



3. Leaf blades (at least those of the lower leaves) deeply lobed or divided (4) 



4(3). Stem densely short-hairy (at least above the middle); leaves pubescent on 

 both surfaces; disk nearly always purple or brown, ovoid or hemis- 

 pheric, not elongating in fruit 3. R. subtomentosa. 



4. Stem essentially glabrous; leaves subglabrous at least on upper surface or on 



both; disk yellow or gray, often elongating to become subcylindric 

 in fruit 4. R. laciniata. 



1. Rudbeckia hirta L. 



Annual or short-lived perennial herb, with roughly pubescent herbage; leaves 

 narrowed to a subpetiolar base or nearly sessile, unlobed but often obscurely toothed, 

 variable in shape but nearly always longer than broad; rays yellow with red-brown 

 spots basally or in the lower half; style branches (of the disk flowers) apically 

 elongate, slenderly subulate (absent in ray flowers); achenes equally quadrangular 

 in transection, the sides flat or slightly bulging. 



Usually growing in dryish situations but occasionally forming large colonies 

 in wettish meadows and marshy land; its several variants are found from Nfld. to 

 B.C.. s. to Fla., Tex., and in the Rocky Mts. to Mex. We have 2 varieties. 



Var. pulcherrima Farw. Annuals usually branching above the middle (if simple, 

 the peduncle not more than a third as long as the height of the plant). R. serotina 

 Nutt., R. flexiiosa T. V. Moore. Nfld. to B.C. and s. to n. Mex. 



Var. angustifolia (T. V. Moore) Perdue. Short-lived perennial, branching at or 

 near the middle (if simple, the peduncle at least half as long as the height of the 

 plant); leaves relatively narrow. R. divergens T. V. Moore. Frequent in sandy 

 wooded areas, e. and s.e. Tex., spring-summer; Ga. and Fla. to Tex. 



1651 



