34 VASCULAR PLANTS. 



42. Eriophyllum, Lag. (Bahia, Lag.) 



Superflua. Ray-flowers ovate, exserted. Scales 

 of the involucre lanceolate, united at the base. 

 Receptacle naked, alveolate. Pappus 4, 8 or 

 12, membranaceous scales, costate, (thickened) 

 at the base. 



IX. \> . flowers yellow. 



43. Monolopia, DC 



Superflua. Scales of the involucre united 

 into a dentate cup. Receptacle conical, naked, 

 papillate. Pappus 0. 



. flowers yellow. 



44. Lasthenia, Cass. 



Superflua. Scales of the involucre united 

 into a dentate cup. Receptacle conical, naked, 

 papillose. Akenes linear compressed; pappus 

 5 — 10 firm scales, sometimes 0. 



. flowers yellow. 



45. Rigiopappus, Gray. 



Superflua. Scales of the involucre linear, 

 erect, rigid, half embracing the akene. Re- 

 ceptacle flat, naked; pappus 3—5 aristae. 



0. flowers pale; leaves alternate. 



46. Chaenactis, DC. 



iEqualis. Flowers of the ray tubular, but 

 frequently enlarged. Involucre hemispherical; 



