(108) 



49. Achillea L. YARROW. 



Superflua. Head oo-flowerad; ray-flowers 6 

 to 6, ligulate, ovate. Involucre ovate; scales 

 imbricate, those of the receptacle hyaline. 

 Akenes marginate ; pappus 0. 11 . 



1. A. MTLLEFOLIUM L. Eay-flowers and disc 

 pale. Common. Summer. 



50, Matricaria L- CHAMOMILE. 



Superflua. JEqualis. Scales of the invo- 

 lucre imbricate. Keceptacle conical, naked. 

 Akenes angulate. Pappus coroniform or 0. 

 Disc yellow; flowers of the ray white. 



1. M. DISCOIDEA DC. Pappus 0; areola of 

 akene merely surrounded by a rim ; ray-flowers 

 white, depauperate. Summer. Common. 



2. M. OCCIDENTALIS Greene. Pappus coro- 

 niform, unequal, the side toward the ray con- 

 siderably developed, the inner side reduced to 

 a rim. Contra Costa. Summer. 



51, Chrysanthemum L. 



Superflua. Involucre hemispherical, spread- 

 ing. Scales co-seriate, imbricate, appressed. 

 Receptacle not conical, naked. Akenes short, 

 somewhat terete, costate, truncate at the apex; 

 pappus 0. 



1. C. REGETUM L. Eay-flowers yellow. 0. 

 Has been found near Oakland. Summer. 



