394 COMPOSITE APARGIDICM 



HIEEACIUM 



costate : outer pappus of 2 persistent bristles and between them some min- 

 ute pointed teeth. Eastern Oregon to California and Arizona. 



M. Torreyi Gray Proc. Am. Acad. ix, 213. Stems 1-12 inches high 

 froiii an annual root, branching from the base: lower leases oblong, rather 

 short, pinnatifid with short and dentate lobes, teeth and lobes callous- 

 mucronate: heads seldom less than half-inch high, broadish-campanulate, 

 short peduncled on the leafy branches : bracts of the involucre lanceolate, 

 acuminate: achenes" linear-oblong, 5-angled by as many salient often 

 almost wing-like ribs, a much less prominent pair in each interval : outer 

 pappus of 2-8 stout persistent bristles, between the tliickish bases of which 

 are minute teeth. Southeastern Oregon to Nevada and Utah. 



104 APARGIDIUM T. & G. Fl. ii, 474. 



Low herbs with fusiform biennial roots, all radical leaves, and 

 rather small heads of yellow flowers on slender scapes. Heads 

 many-flowered, nodding in bud. Involucrenarrow-campanulate; 

 its bracts strongly 1-nerved, .in 2-3 series. Receptacle naked. 

 Achenes columnar, truncate, smooth. Pappus brownish, of copi- 

 ous rather rigid and fragile barbellate-denticulate capillary bris- 

 tles, with some outer and smaller ones nearly smooth. 



A. boreale T. & G. 1. c. Scape solitary, slender, 6-12 inches high, 

 bearing a single head: leaves linear-lanceolate, 3-6 inches long, attenuate 

 at both ends, entire, or obscurely undulate : involucre 6-9 lines high ; of 

 10-15 lanceolate acuminate principal bracts and about as many similar 

 but smaller outer ones. Wet meadows in the high mountains, Alaska to 

 California. 



105 HIERACIUM Tourn. L. Gen. n. 913. 



Perennial herbs with alternate or all radical leaves and small 

 to large erect heads of yellow, rarely white or red flowers in pan- 

 icles or corymbs, or solitary. Involucre several- to many-flower- 

 ed of narrow equal bracts and some short calyculate ones, or 

 sometimes imbricated, not thickened at base nor with thickened 

 midrib. Achenes oblong or columnar, smooth and glabrous, 

 mostly 10-ribbed or striate, either terete or 4 or 5-angled, slightly 

 contracted at the very base, commonly of the same thickness to 

 the truncate summit. Pappus of rather rigid scabrous fragile 

 bristles, brown or brownish, rarely white and soft. 



1 ARCHIERACTUM Fries. Heads corymbosely paniculate. 

 Involucre of the comparatively large heads irregularly more or 

 less imbricated. Achenes columnar. Pappus of numerous un- 

 equal bristles, 



H. Canadense Michx. Fl. ii, 86. Stems robust, 4-6 feet high : leaves 

 from lanceolate to ovate-oblong, acute, sparsely and acutely dentate, or 

 even laciniate, at least the upper partly clasping and broad or broadish at 

 base : involucre usually pubescent when young, occasionally glandular, the 

 narrow outermost bracts loose : pappus sorded. Dry open woods, Oregon 

 and northward to Pennsylvania and Canada. 



2 STENOTHECA T. & G. Fl. ii, 476. Involucre a series of 

 equal bracts and a few short calycula'e ones, usually narrow 



