502 



TREES OF NORTH AMERICA 



with minute dark glands, glabrous on the outer, slightly villose on the inner surface; 

 stamens usually 10, but occasionally 8-12; anthers pale yellow; styles 2-3, surrounded 

 at the base by a broad ring of hoary tomentum. Fruit ripening at the end of Sep- 

 tember and often remaining on the branches for several weeks longer, on erect slen- 

 der pedicels, in broad open many-fruited usually slightly villose clusters, globose, 

 often hairy at the ends until nearly ripe, crimson, very lustrous, \'-^' in diameter; 

 calyx large and conspicuous, the lobes coarsely serrate, reflexed and persistent; flesh 

 thin, dark yellow, dry and mealy; nutlets 2 or 3, about \' long and broad, full and 

 rounded at the ends, rounded and ridged on the back, with a wide high ridge, the 

 ventral cavities deep and irregular. 



A tree, occasionally 15 high, with a tall stem 5'-6' in diameter, covered with 

 pale close bark, stout wide-spreading branches forming an open rather irregular head, 



and stoiit slightly zigzag glabrous light chestnut-brown very lustrous branchlets, 

 becoming dull reddish brown in their second year, and armed with numerous slender 

 usually curved very sharp bright chestnut-brown shining spines 2^'-4' long. 



Distribution. Usually on rich hillsides, often in limestone soil and near the 

 banks of streams; vallev of the St. Lawrence River in the neighborhood of Montreal, 

 through New England to eastern Pennsylvania, and through the region south of the 

 Great Lakes to northern Illinois. 



XVIII. DOUGLASIANJE. 



Leaves broadly ovate to obovate ; fruit subglobose to short-oblong ; calyx-lobes serrate, de- 

 ciduous from the fruit. 131. C. Douglasii (A, B, F, G). 



Leaves lanceolate to oblong-obovate, narrowed at the ends ; fruit short-oblong- ; calyx-lobes 

 entire, persistent on the fruit. 132. C. rivularis (F). 



131. Crataegus Douglasii, Lindl. 



Leaves broadly ovate to obovate, gradually narrowed below to the cuneate entire 

 base, finely serrate above, with minute glandular teeth, and often incisely lobed 

 toward the acute apex, nearly fully grown and coated above and on the midribs and 

 veins below with short pale hairs when the flowers open in May, and at maturity 

 subcoriaceous, glabrous, dark green and lustrous above, paler below, l'-2' long and 



