ROSACEJE 391 



straight orange-brown shining spines l^'-2' long, long persistent on the branches 

 and trunk, finally ashy gray, and becoming sometimes a foot long, with long slender 

 lateral spines. 



Distribution. Dry limestone hills and low moist bottom-lands, Bucks and Dela- 

 ware counties, eastern Pennsylvania. 



25. Crataegus collina, Chapm. 



Leaves obovate to oval or occasionally to rhomboidal, acute, gradually narrowed 

 or broadly cuneate at the entire base, and irregularly and often doubly serrate above^ 

 with glandular incurved or straight teeth, when they unfold bright red and covered 

 with soft pale hairs most abundant along the under side of the midribs and principal 

 veins, less than one third grown when the flowers open at the end of April, and at 

 maturity subcoriaceous, yellow-green on the upper surface, paler on the lower sur- 

 face, glabrous with the exception of a few hairs on the under side of the stout yellow 

 midribs and 4 or 5 pairs of slender primary veins, l^'-2' long, I'-l^' wide; their 

 petioles slender, villose, soon glabrous, more or less winged toward the apex, \'-\' 

 long; on vigorous shoots frequently divided into short broad acute lateral lobes, 

 more coarsely dentate and often 3' long and 2^' wide, with stout broadly winged 

 petioles generally light red like the lower side of the base of the midribs. Flowers 

 ' in diameter, on long stout pedicels, in broad many-flowered villose corymbs; calyx- 

 tube broadly obconic, villose particularly toward the base, the lobes gradually nar- 

 rowed from broad bases, acuminate, usually glabrous on the outer surface, villose 



f- 15 



on the inner surface, finely glandular-serrate, with dark glands, bright red toward 

 the apex; stamens usually 20; anthers large, pale yellow; styles 5. Fruit ripening 

 in September, on stout elongated pedicels, in few-fruited erect or drooping puberulous 

 clusters, globose but sometimes rather broader than long, dull red, marked by small 

 pale dots, '-^' in diameter; calyx enlarged, prominent, the lobes closely appressed, 

 glandular-serrate, mostly persistent; flesh yellow, dry and mealy; nutlets 5, broad 

 and rounded at the ends, ridged and often grooved on the back, about \' long. 



A tree, usually 15-20 but occasionally 25 high, with a tall straight stem often 

 buttressed at the base, frequently armed with numerous large much-branched spines 

 sometimes 6'-8' long, stout wide-spreading branches forming a handsome flat-topped 



