OF ARTS AND SCIENCES. 23 



to fix the characters, and as Nuttall was assured, although he unwit- 

 tingly suppressed the former genus by founding his genus Stylesia 

 upon Lagasca's original Bahia. Bahia oppositifoUa is the only 

 species which approaches Eriophyllum, and it has the distinguishing 

 characters of Bahia. These are, the comparatively lax involucre, 

 open in fruit (or even reflexed when the akenes have fallen), composed 

 of herbaceous or submembranaceous bracts, always distinct and com- 

 monly narrowed at base ; a small receptacle ; and paleas of the pappus 

 witli callous-thickened base or costa : no species is floccose-lanate, 

 although one is canescent-tomentulose. EriophyUum has an erect 

 cupuliform involucre, which does not spread in fruiting, is not rarely 

 gamophyllous at base and sometimes to above the middle, and gen- 

 erally coriaceous rather than herbaceous ; the receptacle varies from 



often united into 2 quadrate scales between tlie two awns. — Dichceta tenella, 



Nutt. 1. c. 



§ 3. PxiLO-'MERrs. Pappus (in one species wanting) of several similar or not 

 very dissimilar paleae, awned or pointed from the summit or muticous, com- 

 monly erose : receptacle not murioate-rougliened by the persistent supports 

 to the akenes, as in the preceding sections : bracts of the involucre more or 

 less carinate-saccate at the middle of base, when mature somewhat embracing 

 the subtended akene, at length deciduous with it : leaves all 1-2-pinnately 

 parted into narrow linear or filiform divisions. — Ptilomeris, Nutt. Trans. Am. 

 Phil. Soc. vii. 382, Actinolepis in part, Benth. & Hook. Gen. 



* Kays 6 or 8, oblong, short-e.xserted : involucral bracts broad : receptacle 

 glabrous, either acutely or obtusely conical : heads small (barely 3 lines high) : 

 plants a span high, minutely pubescent, but hardly at all glandular. 



B. AFFiNis. Pappus of 8 or 10 oblong or lanceolate palea?, with laciniate- 

 setulose margins, some »r most of them produced into an awn which almost 

 equals the disk-corolla, or in the ray muticous and awnless. — Ptilomeris affinis, 

 Nutt. PI. Gamb. 174. — Lately collected anew, at Los Angeles and San Bernar- 

 dino, by Nevin and Parish: probably may hold, as distinct from the next. 



B. TENELLA. Pappus of G to 8 short and firm quadrate or broadly cuneate 

 palete, tlie truncate summit denticulate or nearly entire, not surpassing the tube 

 of the corolla. — Ptilomeris tenella, Nutt. PI. Gamb. 173. Actinolepis {Ptilomeris) 

 tenella, Gray, Bot. Calif., mainly. Recently again collected, at Los Angeles, by 

 Parri/. 



* * Rays 10 to 15, elongated-oblong, exserted : involucral bracts oblong-lanceo- 

 late : receptacle minutely and sparsely pubescent, acutely conical : plants 

 minutely glandular-pubescent, a span to a foot high, diffuse : perhaps both 

 varieties of one, differing mainly in the pappus. 



B. coROXARiA. Ptilomeris coronaria, Nutt. 1. c. Hymenoxys CaJifornica, Hook. 

 Bot. Mag. t. 3828. Actinolepis coronaria, Gray, Bot. Calif., with syn. — Pappus 

 of awn-pointed palea;. 



B. MUTiCA. Ptilomeris mutica, Nutt. 1. c. Actinolepis mutica. Gray, Bot. Calif. 

 1. c, with syn. — Pappus of quadrate-oblong obtuse or truncate paleae. 



