Hymenoxys. composite. 381 



^ 2. Heads radiate : pappus awnless, or none! — Ptilopsis, Nutt. (Plilo- 

 meris, excl. spec, & § Ptilopsis, Nutt.) 



2. H. mutica : scales of the pappus 6-8, oblong, truncate or obtuse, lacini- 

 ate at the summit, equal, shorter than the proper tube of the corolla ; that of 

 the ray smaller. — Ptilomeris mutica, Nutt. ! L c. 



California, "with the preceding, Nuttall. 



3. H.calva: pappus of the ray and disk none. — Ptilomeris (Ptilopsis) 

 anthemoides, Nutt. ! I. c. 



California, with the preceding, and in no way distinguishable, apparently, 

 except by the achenium. Nuttall ! 



125. ACTINELLA. Pers. syn. 2. p. 469 ; Nutt. gen. 2. p. 173. 



Actinea, Jitss. — Ptilepida, Rnf. — Picradenia, Hook. 



Heads many-flowered ; the ray-flowers 8-12, pistillate, ligulate, cuneate- 

 oblong, 3-toothed or lobcd at the apex ; those of the disk tubular, perfect. 

 Scales of the hemispherical involucre lanceolate or ovate, appressed, in 1-3 

 series, nearly equal, rather shorter than the disk. Receptacle hemispherical 

 or conical, naked. Corolla of the disk cylindraceous, with the proper tube 

 very short, 5-toothed ; the teeth erect glandular-bearded. ;Sranches of the 

 style linear, truncate and barbellate at the apex. Achenia turbinate, short, 

 densely silky-villous. Pappus of 5-12 ovate or ovate-lanceolate membrana- 

 ceous 1-nerved and awned scales with denticulate or eroded margins. — 

 Low chiefly perennial or suffruticose (American) plants ; whh the leaves 

 linear or lanceolate, entire or 2-3-parted, impressed-punctate; the cauline 

 alternate, sessile. Heads solitary, pedunculate. Flowers yellow, rarely 

 white ? sprinkled with bitter resinous globules. 



* Caulescent : stems numerous from a thick caudex : leaves sparingly pinnately parted. 



1. A. Richardsonii (Nutt.): puberulent; leaves petioled, rigid, irregularly 

 3-7-parted towards the summit ; the segments glandular-punctate, fihform- 

 linear, entire, or the terminal one 2-toothed ; scales of the involucre ovate- 

 lanceolate, in two series, the exterior united at the base ; pappus of 5-7 ovate- 

 lanceolate cuspidate-awned scales. — Nutt..' in trans. Amer. ])hU. soc. {n. ser.) 

 7. p. 379. Picradenia Richardsonii, HooJc. ! Ji. Bor.-Avi. I. p. 317, t. 108; 

 DC. 2>i'odr. 5. p. 065. 



About Carhon House, on the Saskatchawan, Richardson ! — A span high, 

 rigid, branching above. Heads an inch in diameter, including the (8-10) 

 obovate-oblon^ yellow rays. Branches of the style flat, truncate and beard- 

 ed at the apex! Achenia clothed with long tawny villous hairs. Pappus 

 shorter than the corolla of the disk. 



* ♦ CcBspitose, mostly du-arf and acaidcscent : leaves crowded or rosulate, usually evr- 

 tire : scapes simple, naked. 



2. A. acaulis (Nutt.) : leaves densely clustered on the thick caudex, line- 

 ar-spatulate, silky-villous, as well as the scapes when young, and the invo- 

 lucre ; the scales of the latter lanceolate-oblong, in 2 series ; scales of the 



