Hall.Compositae of Southern California. 203 



the pappus and achenial hairs are reddish-brown, in others white, 

 but no other difference can be detected. 



76. HYMENOXYS Cass. 



Herbaceous plants with aromatic herbage, alternate leaves, 

 and pedunculate heads. Ray-flowers pistillate or the heads 

 homogamous. Bracts of the involucre in two series, in our 

 species the narrow and rigid outer bracts united at base into a 

 shallow cup enclosing the broadly oblong obtuse inner ones. 

 Flowers yellow. Achenes turbinate, hairy. Pappus of 5 to 12 

 conspicuous hyaline paleae. 



For reasons stated by Dr. Cockerell in his revision of the 

 North American Species of Hymenoxys, 50 it seems advisable to 

 unite Hymenoxys and Picradenia into one genus. The oldest 

 tenable name for this group is Hymenoxys Cass. (1828), Picra- 

 denia Hook, dating from 1834. This group cannot take the name 

 Actinella, since Actinella Nutt. (1818) is apparently a distinct 

 genus, distinguished by habit and involucre (= Tetraneuris 

 Greene, Pitt. iii. 265). There is also an earlier Actinella Pers. 

 (1807), the only species of which is now referred to Cephalophora 

 (Gray says wrongly so referred) . 



Leaves pinnatifid. 



Pappus-paleae very obtuse, erose at summit 1. H. Cooperi. 



Pappus-paleae acuminate or cuspidate. 



Involucre hemispheric, about 12 mm. broad; outer bracts 12 to 14 



2. H. biennis. 



Involucre campanulate, 6 to 9 mm. broad; outer bracts 8 to 10: var. 



excurrens of 3. H. chrysanthemoides. 



Leaves entire 4. H. latissima. 



1. H. Cooperi (Gray) Ckll., Bull. Torr. Club xxxi. 495 (1904). 

 Actinella Cooperi Gray, Proc. Am. Acad. vii. 359 (1868). 



Plant 6 dm. or more high, the stems paniculately branched 

 above: herbage puberulent: leaves much parted into nearly fili- 

 form lobes : involucre nearly hemispheric ; outer bracts 6 to 10 : 

 achenes densely covered with ferruginous hairs : pappus-paleae 

 5, of firm texture, ovate or oblong, with very obtuse erose summit, 

 not half the length of the disk-corolla. 



so Cockerell, Bull. Torr. Club xxxi. 461 (1904). 



