Genus 20.] 



THISTLE FAMILY. 



329 



3. Eriocarpum spinulosum 

 (Xutt.) Greene. Cut-leaved Eriocar- 

 pum. (Fig. 3668.) 



Amel/us spinulosiisruT&h, Fl. Am. .Sept. 2:564. 



1814. 

 Aplopappiis spi n II /ostis DC. Prodr. 5; 347. 1836. 

 Eriocarpum spinulosum Greene, Erythea, 2: 



108. 1894. 



Canesceut or glabrate, much branched at 

 the base, perennial from thick woody roots, 

 6'-l5' high. Leaves pinnatifid, sessile, 

 linear to ovate in outline, %'-il4' long, 

 i"-2>2" wide, the lobes with bristle-pointed 

 teeth; heads several or numerous (rarely 

 solitary), 6"-i2" broad; involucre hemis- 

 pheric, its bracts linear, acute, appressed; 

 rays narrow; achencs pubescent, narrowed 

 below; pappus soft and capillary. 



In dry soil, Northwest Territory and North 

 Dakota to Nebraska and Texas, west to Colo- 

 rado, -Arizona and Mexico. March-Sept. 



20. STENOTUS Nutt. Trans. Am. Phil. Soc. (II) 7: 334. 1841. 



Low undershrubs, with coriaceous narrow entire evergreen leaves, scapose or leafy stems, 

 and rather large heads of both radiate and tubular yellow flowers. Involucre mostly hemis- 

 pheric, its bracts imbricated in several series, appressed, ovate to lanceolate. Receptacle 

 alveolate. Disk-flowers perfect, their corollas tubular, usually somewhat enlarged upward, 

 deeply 5-toothed. Ray-flowers fertile. Anthers obtuse at the base. Appendages of the 

 style-branches short, lanceolate. Achenes white-villous. Pappus of soft white capillary 

 bristles. [Greek, narrow, referring to the leaves.] 



About iS species, natives of western North America. 



I. Stenotus armerioides Nutt. Narrow-leaved Stenotus. (Fig. 3669.) 



Slenolus armerioides Nutt. Trans. Am. Phil. Soc. (II) 



7: 335. 1841. 

 Aplnpappus armerioides A. Gray, Syn. Fl. i; Part 2, 



132. 1884. 



Perennial, tufted from a branched woody caudex, 

 glabrous throughout; flowering stems slender, 

 naked above, or quite leafless, \'-%' high. Basal 

 leaves numerous, narrowly spatulate or linear, 

 acute or acutish, iirm, i'-3' long, \"-2" wide, en- 

 tire, narrowed below; stem leaves usually 1-3, 

 sessile, linear, sometimes none; head commonh- 

 solitary, about \' broad; involucre campauulate, 

 4"-6" high, its bracts broadly oval, green, ap- 

 pressed, obtuse or retuse, scarious-margined, or the 

 inner ovate-oblong and acutish; raysS-io; achenes 

 canescent or villous; pappus bristles soft, white. 



In drj', mostly rocky soil, western Nebraska to 

 Wyoming, Utah and New Mexico. June-July. 



21. ISOPAPPUS T. & G. Fl. N. A. 2: 239. 1841. 



Rough-hairy annual or biennial herbs, loosely pauiculately branched, with alternate linear 

 to lanceolate i-nerved entire or somewhat toothed leaves, and small slender-peduncled heads 

 of radiate and tubular yellow flowers. Involucre campanulate-cylindric, its appressed 

 lanceolate or subulate bracts in 2 or 3 series. Receptacle alveolate. Ray-flowers 5-12, 

 pistillate. Disk-flowers 10-20, perfect. Anthers not sagittate. Style-appendages narrow, 

 hirsute. Achenes terete, narrowed below, silky-villous. Pappus a single series of rough 

 capillary bristles, nearly equal in length. [Greek, equal pappus.] 



Two known species, natives of the southern United States. 



