480 



The Thorn Trees 



This species runs into numerous forms. Cratcegtis succulenta Schrader has 

 about 20 stamens and larger fruit with larger nutlets. C. rhornhijolia Sargent has 

 smaller fruit and nutlets, about 10 stamens and more hairy cor}^mbs. C. integriloha 

 Sargent has entire calyx- lobes and about 10 stamens; it is common about Montreal, 

 Canada. 



48. PEAR THORN Crataegus Chapmani (Beadle) Ashe 

 Cratcegus tomentosa Chapmani Beadle 



This species occurs from central New York, southw^ard through western 

 New Jersey and along the foothills of the Appalachian Mountains to northern 



Georgia and westward through southern 



Ontario to southern Minnesota, eastern 

 Kansas, and Missouri. It is also called 

 Pear haw. It is a tree sometimes 7 me- 

 ters high, with ascending or spreading 

 branches, forming a broad crown; the 

 bark is pale gray to dark brown, fur- 

 rowed; the twigs are dark orange and 

 tomentose when young, becoming gray 

 and smooth and are occasionally armed 

 with slender spines 3 to 5 cm. long. 



The leaves are rhombic-ovate, 4 to 

 II cm. long, 3 to 8 cm. wide, pointed or 

 long-pointed at the apex, wedge-shaped 



Pear Thorn. 



Fig. 438 



at the base, doubly toothed and generally lobed, hairy on the upper surface when 

 young, becoming rough, hairy beneath, particularly along the veins, thin, gray- 

 green; leaf-stalks wing-margined, glandular-hair}% about 2 cm. long. The flowers 

 are about 15 mm. wide, in many- flowered, whitish woolly-hairy corj^mbs; the calyx- 

 lobes are lanceolate, long-pointed, less hair^^ than the tube; stamens 10 to 20; 

 anthers small, pink; styles 2 or 3. The fruit ripens late; it is pear-shaped or oval, 

 10 to 15 mm. long, orange-red; pedicels hairy; flesh yellow, thick; nutlets 2 to 3, 

 5 to 7 mm. long, the nest 5 to 6 mm. thick. 



49. DOUGLAS' THORN Crataegus Douglasii Lindley 



Cratagiis punctata brevispina Douglas. CratcBgus brevispina Farwell 



Douglas' thorn occurs along banks of streams from British Columbia to north- 

 em California and eastward in the northern Rocky Mountains to the Bighorn 

 Mountains in Wyoming; on the shores of Lake Superior in northern Michigan, 

 and on Michipicotin island. It is a tree sometimes 12 meters high, with ascending 

 branches forming a round-topped crown; the twigs are reddish, smooth, and armed 

 with short, stout, red spines from i to 3 cm. long. 



