COMPOSITAE (COMPOSITE FAMILY) 503 



Loosely caespitose; leaves narrowly to broadly oblanceolate; stems leafy. 

 Caudex branches with enlarged -crowns sheathed with the dead 



petioles ...... 3. S. armerioides. 



Caudex open with slender naked branches . . . . . 4. S. latifolius. 



1. StenotusacauUsNutt.Trans.Am.Phil.Soc.il. 7: 334. 1841. Depressed- 

 caespitose from a multicipital lignescent caudex: leaves rigid and persistent, 

 crowded on the crown of the caudex and a few on the scapiform flowering 

 stems, spatulate to linear, 2-4 cm. long, mucronate, more or less 3-nerved, 

 commonly scabrous: scapiform flowering stems 3-12 cm. high: heads mostly 

 solitary, many-flowered, radiate; bracts of the involucre ovate to ovate- 

 lanceolate, mucronately acute or acuminate, destitute of greenish tips. 

 Shale and clay slopes and cliffs; Saskatchewan to Colorado and westward. 



2. Stenotus caespitosus Nutt. 1. c. Habit of the foregoing; glabrous or 

 nearly so: leaves crowded on the crowns of the woody caudex, narrowly 

 lanceolate or linear, acute, 3-nerved; those of the simple or branching scapes 

 3-4: bracts of the involucre broadly ovate, acute, membranaceous, erose- 

 ciliate, imbricated in 3 series: appendages of the style subulate-linear, mi- 

 nutely pubescent. Aplopappus acaulis glabratus. Wyoming to Montana 

 and Nevada. 



3. Stenotus armerioides Nutt. 1. c. Caespitose and rigid, 10-15 cm. high, 

 glabrous: leaves crowded on the crowns of the thick woody caudex and on 

 the lower part of the stem, elongated spatulate-linear, obscurely 3-nerved; 

 those of the peduncle 1-2: bracts of the involucre roundish-oval, very obtuse, 

 coriaceous, with abrupt scarious margins and greenish tips, closely imbri- 

 cated, somewhat in 3 series: style with short and thick lanceolate appendages. 

 [S. falcatus Rydb. Bull. Torr. Bot. Club 27: 616. 1900 (?).] Dry cliffs and 

 shale slopes. 



4. Stenotus latifolius A. Nels. Bot. Gaz. 37: 266. 1904. Caudex woody, 

 with numerous slender, naked branches; herbaceous stems slender, leafy, 

 monocephalous, 10-15 cm. high, naked pedunculate above, glabrous but ob- 

 scurely glutinous: leaves glabrous, slightly glutinous, acute or apiculate, 

 3-nerved; the crown leaves not persistent, small, spatulate, 7-12 mm. long; 

 stem leaves longer, several (5-7), the lowest broadly spatulate-cuneate, the 

 upper broadly oblong to lanceolate, 2-3 cm. long: heads 10-12 mm. high; 

 the bracts in 3-4 series, oblong, abruptly acute, light green with narrow 

 scarious margin: rays several, rather short: pappus-bristles slender, white, 

 about as long as the somewhat angled canescent achene. In the mountains 

 of Utah. 



16. TONESTUS A. Nels. 



Low, herbaceous perennials from woody roots, having a short more or less 

 branched subligneous caudex. Stems simple, a few to several centimeters 

 high, leafy throughout, monocephalous. Leaves herbaceous, obscurely 3- 

 nerved, spatulately tapering to a short margined petiole. Heads relatively 

 large (15-25 mm. broad); the involucral bracts herbaceous, in about 2 loosely 

 imbricated rows, usually with 1-several outer foliaceous ones. Rays conspic- 

 uous, 10 or more; the disk-flowers more numerous. Pappus soft and white, 

 equaling the corolla. Style tips slender, subulate-elongated. Achenes gla- 

 brous or pubescent. Aplopappus in. part. 



Stems very short (1-5 cm.); involucral bracts obtuse . . . . 1. T. pygmaeus. 

 Stems slender, 5-15 cm. long; involucral bracts acute . . . . 2. T. Lyallii. 



1. Tonestus pygmaeus (T. & G.) A. Nels. Bot. Gaz. 37: 262. 1904. Soft- 

 pubescent or glabrate, not viscid or glandular: leaves linear-spatulate to 

 spatulate-oblong: involucral bracts oblong, outer ones foliaceous and loose, 

 very obtuse, equaling the thinner innermost: achenes pubescent. Alpine 

 region of the Colorado and the Wyoming Mountains. 



2. Tonestus Lyallii (Gray) A. Nels. 1. c. Rather taller, larger-leaved, 

 viscid-puberulent: leaves obovate-spatulate to oblanceolate: involucre glan- 

 dular; the bracts lanceolate, acute, sometimes 2 or 3 outermost oblong and 



