338 COMPOSITE xanthium 



RUDBECKIA 



ularly serrate: fruiting involucre about an inch long, densely beset with 

 rather long prickles, the stout beaks at maturity usually hooked at the tip 

 or incurved, the surface and base of the prickles more or less hispid, some- 

 times glabrate. Sandy shores and waste places Brit. Columbia to Califor- 

 nia and the eastern States. 



* * Leaves attenuate at both ends, short-petioled ; their axils triply 



spinescent. 



X. spinosum L sp. 987. Stems stout. 1-2 feet high, much branched: 

 leaves ovate-lanceolate with cuneate base, the larger 3-lobed or incisely 

 pinnatifid, green and glabrate above, white-tomentose beneath, with long 

 and slender 3-parted yellow spines in the axils : fruiting involucre solitary 

 or few, in upper axils, cylindraceous, half-inch long, obtuse, armed with 

 short weak prickles, inconspicuously 1-2 beaked or pointless 



Subtribe Hi, Verbesinese Less. Rays lignlate and either fertile 

 or neutral, not rarely wanting, the ligule not becoming papery and 

 ■persistent on the fruit, but sometimes marcescent. Disk-flowers her- 

 maphrodite and fertile or often some of the inner ones sterile, sub- 

 tended and sometimes enwraped by the chaff of the receptacle. An- 

 thers often blackish. Achenes various but those of the dish never 

 obcompressed. Pappus cupulate or coroniform, or of teeth or awns 

 from the principal angles, or of some squamellse, or of a few stout 

 bristles, or none. 



39 RUDBECKIA L. Gen. n. 980. " 

 Mostly perennial herbs with alternate leaves and rather large 

 and showy heads terminating the stem or branches. Heads 

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

 of the disk tubular and perfect. Bracts of the involucre folia- 

 ceous, in about two series, spreading. Receptacle conical or 

 often more or less elongated and spiciform. Disk-corollas with 

 a short but usually manifest proper tube and erect or spreading 

 teeth. Style-branches tipped with an acute or obtuse hispid 

 appendage. Achenes 4-angled, prismatic, in some species 

 quadrangular-compressed. Pappus a coriaceous or firm-scari- 

 ous and often 4-toothed crown, sometimes deep and cupulif orm . 

 sometimes obsolete, or none. 



R. Californica Gray Proc. Am. Acad. vii. 357. Stem simple, 2-6 feet 

 high 3-5-leaved, the long and naked peduncle-like summit bearing a single 

 large head : leaves finely soft-pubescent, 3-10 inches long, ov tte to oblong- 

 lanceolate, acuminate, pinnately veined somewhat toothed; the middle' 

 ones sometimes with a pair of lateral lanceolate lobes at base, uppermost 

 sessile, lower tapering into a slender petiole : bracts of the involucre linear : 

 rays 2-3 inches long, narrowyl oblong, yellow : disk columnar 1-2 inches 

 long, d sky brown: achenes compressed-prismatic, 2 lines long, crowned 

 with a pappus of 4 irregular thickish chaffy teeth, more or less united at 

 base into acup. Wet meadows and cold spring runs, southwestern Oregon 

 to California. 



R. occidentalis Nutt. Trans. Am. Phil. soc. vii, 355. Nearly glabrous 

 and smooth, or somewhat scabrous-puberulent : stems stout, 2-8 feet high, 

 nearly simple : leaves ovate or ovate-lanceolate, acuminate, entire or irreg- 

 ularly and sparingly dentate, 4-8 inches long, upper ones sessile by a 

 rounded or subcord^te base, lower ones abruptly contracted into a short 



