66 



NORTH AMERICAN FLORA 



[Volume 34 



Stamens included ; some of the outer bracts spreading above. 

 Perennials or biennials; corollas all alike; squamellae 8-15, linear, lanceo- 

 late or oblong, with no smaller outer ones. (Macrocarphus.) 

 Plants not suffrutescent; leaves bipinnatifid or pinnatifid with lobed 

 divisions. 

 Leafy-stemmed plants. 



Plant densely white-floccose, usually somewhat villous. 



Leaves mostly basal, broadly obovate in outline, with 

 approximate divergent divisions; branches of the in- 

 florescence mostly diverging at the base and curved 

 upwards. 

 Leaves scattered, ovate or lanceolate in outline; branches 

 of the inflorescence erect or ascending, strict. 

 Plant 1-3 dm. high, not fruticulose; leaves regularly 



pinnatifid. 

 Plant 3-4 dm. high. 



Leaves narrow, almost regularly pinnatifid; plant 



often fruticulose at base. 

 Leaves broader, interruptedly pinnate with smaller 

 segments interposed between the larger ones; 

 plant not fruticulose. 

 Plant sparingly floccose, in age glabrate and greener. 



Squamellae about half as long as the corollas; low perennials, 



1—2 dm. high, branched at the caudex. 

 Squamellae at least two-thirds as long as the corollas. 



Bracts shorter than the disk ; stem 2—4 dm. high; biennials 

 or perennials with a persistent caudex. 

 Outer bracts not spreading; stout biennial, usually 



simple below. 

 One or two of the outer bracts more or less spreading ; 

 slender perennial with branched caudex. 

 Bracts equaling the disk; stem 1-2 dm. high, from a 

 cespitose rootstock. 

 Subscapose perennials, with rosullate leaves and nearly naked 

 peduncles. 

 Leaves oblanceolate, elliptic or linear in outline; plants with a 

 cespitose caudex. 

 Leaves oblanceolate or elliptic in outline, sparingly floccose. 

 Inner bracts acuminate; leaf -blades narrowly lanceolate 



in outline. 

 Inner bracts barely acute; leaf-blades broadly ovate or 

 obovate in outline. 

 Involucre floccose and glandular-puberulent, not sub- 

 tended by smaller bracts. 

 Involucre densely glandular hirsute, subtended by 

 one or two shorter and looser bracts. 

 Leaves linear in outline, densely white-woolly. 

 Leaves obovate, cuneate, or flabelliform in outline, villous; plant 

 with a cespitose rootstock. 

 Involucre 12-15 mm. high and broad; bracts linear, the 



inner acute. 

 Involucre about 8 mm. high and broad; bracts linear - 

 spatulate, rounded at the apex. 

 Plants suffrutescent ; leaves pinnate with linear, usually entire divisions. 

 Leaf -segments short; involucre 12-13 mm. high; squamellae 13-15. 

 Leaf-segments long; involucre 18-20 mm. high; squamellae 8-12. 



20. C. macrantha. 



21. C. brachiata. 



22. C. achilleaefolia. 



23. C. imbricata. 



24. C. cheilanthoid.es. 



25. C. humilis. 



26. C. Douglasii. 



27. C. rubricaulis. 



28. C. peduncular ia. 



29. C. minuscula. 



30. C. alpina. 



31. C. pumila. 



32. C. santolinoides. 



33. C. nevadensis. 



34. C. Evermanii. 



35. C. Parishii. 



36. C. suffrutescens. 



1. Chaenactis artemisiaefolia A. Gray, Proc. Am. Acad. 10: 74. 



1874. 



Acarphaea artemisiaefolia Harv. & Gray; A. Gray, Mem. Am. Acad. II. 4: 98. 1849. 

 Acicarphaea artemisiaefolia Walp. Ann. 2: 877. 1852. 



A branched annual; stem striate, 3-5 dm. high, scurfy-pubescent when young, glandular- 

 puberulent above; leaves 5-10 cm. long, scurfy when young, more or less glandular, especially 

 beneath, bi- or tri-pinnatifid with linear or oblong, divergent and irregular divisions; heads 

 loosely cymose; peduncles 3-10 cm. long, glandular; involucre about 10 mm. high and 15-20 

 mm. broad; bracts linear, acuminate or acute, densely glandular-puberulent and viscid- 

 hirsute; corollas ochroleucous, 6 mm. long; tube glandular-puberulent; marginal corollas only 

 slightly enlarged; achenes somewhat compressed, finely striate, somewhat clavate; pappus 

 wanting, represented by a callous margin. 



Type locality: California. 



Distribution: Southern California and Lower California. 



Illustration: Bot. Mex. Bound. Surv. pi. 32. 



