THISTLE FAMILY 945 



sessile, hirsutulous; heads solitary at the ends of the stem and branches; invo- 

 lucres 6 mm. high; flowers yellow, turning purplish or whitish. Dry ground: 

 Cahf.— Ida.— Wahs. Son. Mr. 



100. CHAMAECHAENACTIS Rydb. 



Cespitose scapiferous perennial, branching below the surface of the groimd 

 and with a woody root. Leaves all basal and simple, coriaceous, white-strigose 

 below, sparingly hirsute and punctate above. Involucral bracts about twelve, 

 in tw^o series, the inner series longer and with scarious-niargined, reddish tips. 

 Corolla fiesh-colored, with equal lobes. Stamens included. Style-tips broad, 

 Achenes clavate, densely villous. Pappus of eight nearly equal squamellae, with 

 prominent midrib and erose tips. 



1. C. scaposa (Eastw.) Rydb. Leaves petioled; blades oblong or elliptic, 

 to orbicular 8-12 mm. long, coriaceous, entire or crenate, with revolute margms, 

 strigose-canescent; scape 3-8 cm. long; involucres about 15 mm. high and broad; 

 bracts oblong, obtuse, densely hhsute-villous. Chaenachs scaposa Eastw. 

 Adinella carnosa A. Nels. Dry mesas and clayey soil: w Colo.— e Ltah. My- 



Je. 



101. CHAENACTIS DC. Morning Brides. 



Annual biennial or perennial herbs. Leaves alternate, usually pinnately 

 dissected ' Heads discoid, but the marginal flowers often with enlarged coroUas. 

 Involucre campanulate or turbinate; bracts herbaceous in 2 series; receptacle 

 alveolate, naked or in some species bristly. Flowers hermaphrodite and fertile; 

 corollas yellow, w-hite, or flesh-colored, the throat cyhndric or m some species 

 funnelform in the marginal flowers. Achenes linear terete or oval m cross- 

 section, or obscurely 4-angled, pubescent. Pappus of 4-16 hyahne squamellae. 



■ 



^"^ C^oroilas yellow; pappus of minute callous squameUae. ^ J" ^- ^^'""• 



Corollas white or flesh-colored; pappus of well developed squamellae. 

 Stamens partly exserted; bracts all appressed. t^Wc+Ixt 



Involucral bracts acuminate; receptacle usually somewhat |*^^*^^;^^^;^^^^^.„^.^, 



Involucral bracts obtuse or merely acute; receptacle naked ^, . . , ^ 



Leaves bipinnatifid. 3. C. s^^rw^^^^ 



Leaves simple, spatulate-lmear. . 4. c. cusicut. 



Stamens included; some of the outer bracts with spreading tip|. ^ ^^^^.^^^j^^^ 



Perennials. , ^ ^ 



Leafy-stemmed plants. 



"^^'^1 Pw^^moSlv^b^^^ obovate in outline, %s'ith approximate divergent 



■^ diA.'isions ; branches of the inflorescence usually divergent at the base 



and curved upwards 6. C. brachiala. 



Leaves scattered, ovate or lanceolate in outline; branches of the inflorescence 



ascending or erect, strict. ' , i • ^-r^ 



Plant 1-3 dm. high, not fruticulose; leaves regularly P^^"^^^^^7;2.;^^^^^^jj-^ 



F. 



■^^^Leav^ iSrrow. mostly regularly pinnatifld; plant often fruticulose at 



the base 8- ^- i^^^^cf^ta. 



Leaves broader, interruptedly pinnatifld. with smaller segments inter- 

 posed between the larger ones ; plant not fruticulose. 

 ^ 9. C. cheilanthoides. 



Plant sparingly floccose, in age greener and glabrate. , o ^^ ni^h 



Squamellae about half as long as the corolla; low perennials. 1-2 dm. high, 

 branched at the caudex. 10. C. humuis 



Sauamellae at least two-thirds as long as the coroUas. .^i, ^ ^^4. 



^Bracts shorter than the disk; stem 2-4 dm. high; ^^^^"^^^^^^§^^^^1"^^^' 



Bracts eQualling the disk; stems 1-2 dm. high, from a ""f^^^^l^^^f^^^ 

 Subscapose perennials, with rosulate leaves and nearly naked peduncles. 



cespitose 



Inner bracts acum 



13. C. minuscula, 

 Imier bracts merely acute; leaf-blades oblanceolate or ^Y4''c?^a?p?n^^' 



if-blades obovate-cuneate or flabeUate in outline; plant ^^^"^^^^11^^ 

 stock. a. . . 



34 



