52 KEYS TO THE GENERA 



* Leaves alternate with entire ed.^es (sometimes very crowded but 



never truly opposite or whorled). (A.) 

 A. Leaves thick and fully or nearly evergreen. (B.) 



B. Leaves with rolled edges. L^dum (p. 20.']). Leiophyllum 



(p. 2(>3). 

 B. Leaves without rolled edges. (C.) 



C. Leaves needle-shaped and 4-angled. Picea (p. 326). 

 C. Leaves linear, sharp-pointed, green below. Taxus (p. 341). 

 C. Leaves linear, blunt, with white lines below. Tsuga (p. 32(1). 

 C. Leaves broad at base, ovate, pointed; twigs green. (South.) 



Ruscus (p. 323). 

 C. Leaves very hairy ; flowers cup-shaped with 10 stamens in 



dents. Kalmia (p. 256). 

 C. Other evergreens with small alternate entire-edged leaves. 

 (D.) 

 D. Flowers tubular with 4 spreading lobes. Daphne (p. 208). 

 D. Flowers bell-shaped, 4-lobed in drooping clusters. Erica 



(p. 254). 

 D. Flowers small, peculiar, in erect clusters. Ceanothus 

 (p. 97). 

 A. Leaves thinner and not evergreen. (E.) 

 E. Flowers yellow, pea-shaped ; twigs green. Genista (p. 114). 

 E. Flowers regular of 5 separate petals. Spirrea (p. 146). 

 E. Flowers generally pink in very small clusters ; leaves minute, 

 clasping the stem at base on thread-like twigs. Tamarix (p. 73). 



* Leaves alternate with notched edges. (F.) 



F. Leaves whitish or silverj^-gray, much divided into lobes ; plant 

 aromatic. Santolina (p. 243). 



F. Other shrubs with notched, small leaves. Spir^a (p. 146). ilex 

 crenata (p. 88). 



* Leaves opposite, thick, and evergreen (including scale-like leaves 



covering the stem). (G.) 



G. Leaves linear and sharp-pointed. Juniperus (p. 337). 



G. Leaves oval and about flat. Buxus (p. 306). Ceanothus (p. 07). 

 G. Leaves oval with rolled edges. Leiophyllum (p. 263). 

 G. Leaves very small, \ inch or less, and pressed to the stem which 

 they practically cover. (H.) 

 H. Flowers yellow, May-July. Huds6nia (p. 72). 

 H. Flowers pink or white, July-September. Erica (p. 254). Cal- 



luna (p. 255). 

 H. Flowers inconspicuous ; fruit a cone. Thiija (p. 328). 



* Leaves opposite and not fully evergreen. Lonicera (p. 230). 



* Leaves whorled on the stem. (I.) 



