(271) 



tirely closed in a prickly, irregularly ruptur- 

 ing involucre. — ^2 . 



1. C. CHRYSOPHYLLA A. DC — Tamalpais. 

 Santa Cruz mountains. Summer. 



In Northern California a tall tree, in our lo- 

 cal flora, a slirub. 



3. Corylus Tourn. Hazel. 



Monoecious. Aments slender. Scales (bracts) 

 imbricated. S flowers besides the scales 2- 

 bracteolate. Stamens 8; anthers 1-celled. 

 ? flowers immersed into a bud; uppermost 

 scales containing flowers, the rest empty. 

 Ovary 2-bracteolate, crowned by a minute per- 

 igoniuni, 2-celled; stigmas 2. Fruit a nut, sur- 

 rounded by a large incised involucre, formed 

 by the growth of the two bractlets. — ^ . 



1. C. ROSTKATA Ait. — Common. Spring. 



Family 2. BETULACE^. 



H3q3ogynous. $ ament : bracts shield-shap- 

 ed, each enclosing 3 flowers with minute peri- 

 gonium and four stamens. ? aments : bracts 

 3-lobed, each enclosing 3 naked flowers; 

 ovary 2-celled; cells 1-ovulate; styles 0; stig- 

 mas 2. Fruit an akene (nutlet) aflixed to the 

 lignescent bract, and collected into a strobi- 

 laceous inflorescence. 



1, Alnus Tourn. Alder'. 



Fruit lignescent; nutlets attached to lignes- 

 cent bracts on a lignescent axis. — ^ . 



