376 COMPOSITAE. 



perfect; receptacle elongated, becoming columnar; pappus a 

 chaff-like cup or 4 chaffy teeth more or less united into a cup; 

 akenes quadrangular and mostly laterally compressed. 



Rudbeckia birta L. Black Eyed Susan. Herbage hispid to hirsute- 

 pubescent; stems erect, 30-60 cm. high; leaves lanceolate to oblong, entire or 

 sparingly serrate, 3-5-nerved, the lower ones petioled, the cauline sessile; 

 heads solitary or few, long-peduncled; ray-flowers 10-20, orange-yellow; disk 

 ovoid, dark brown; chaff of the receptacle linear, acute; pappus none. 



A native of the eastern states, sparingly introduced in fields. 



518. BALSAMORHIZA. 



Low perennials; leaves mostly radical; heads large, usually 

 solitary; flowers yellow; receptacle flat or barely convex with 

 linear-lanceolate chaff; pappus none; ray-akenes obcompressed ; 

 disk-akenes prismatic-quadrangular or laterally compressed. 



Leaves entire or merely dentate ; herbage green ; involucre not 



woolly. B. deltoidea. 



Leaves pinnately cleft, parted or divided; herbage canescent; 



involucre puberulent to lanate. B. balsamorhiza. 



Balsamorhiza deltoidea Nutt. Herbage green, scabrous and sparsely 

 pubescent or glabrate; stems erect, 20-40 cm. high; radical leaves ovate- 

 lanceolate to deltoid, acute, cordate or subcordate at base, entire or irregularly 

 serrate, green on both sides, 10-25 cm. long, long-petioled ; cauline leaves two, 

 small, lanceolate, near the middle of the stem; heads solitary or sometimes 3; 

 tegules linear-lanceolate, the outer ones foliaceous and spreading; ray-flowers 

 2-4 cm. long. 



Prairies, Vancouver Island to California. First collected by Nuttall near 

 the mouth of the Willamette River. 



Balsamorhiza balsamorhiza (Hook.) Heller. Herbage canescent with 

 silky or more or less tomentose pubescence; stems 20-30 cm. high, bearing a 

 pair of small opposite leaves near the base; radical leaves oblong-lanceolate 

 in outline, pinnately to bipinnately parted into linear segments or merely 

 pinnatifid or incised; involucre woolly to merely pubescent; tegules lanceolate, 

 the outer sometimes foliaceous. 



Prairies, rare west of the Cascade Mountains; first collected at Fort Van- 

 couver, Washington, by Douglas. 



519. WYETHIA. 



Perennial herbs; stems simple, rarely branching; leaves alter- 

 nate, mostly entire and ample; heads many-flowered, solitary or 

 few, medium or large; flowers yellow; ray-flowers elongated, 

 pistillate or fertile; pappus a chaffy crown or cup; ray-akenes 

 neither obcompressed nor laterally compressed. 



Wyethia angustifolia (DC.) Nutt. Somewhat hirsute with short white hairs; 

 stems 30-60 cm. high; basal leaves long-lanceolate, mostly entire, acuminate, 

 20-40 cm. long; cauline sessile, smaller and broader; head long-pedunculate; 

 involucre campanulate, loose; tegules broadly lanceolate, green and herbaceous, 

 ciliatc, equalling the disk; ray-flowers 4 cm. long; akenes pubescent at summit; 

 pappus awns stout, subulate, minutely hirsute, 1-2 in the disk-flowers, 3-4 

 in the ray-flowers. 



Moist places, Willamette Valley and southward. 



