ROSE FAMILY 



All our thorns are attractive in habit, foliage, flower and 

 fruit and are worthy of cultivation. One difficulty in obtain- 

 ing them lies in the slow germination of the seed, which often 

 requires two years. 



BLACK THORN. HAWTHORN 



Crahcgus tomentbsa. 



Not very common tree, fifteen or twenty feet in height, with slen- 

 der contorted branches which form a wide flat head, often a shrub 

 with many straggling stems. Roots fibrous. Branchlets armed with 

 sharp slender spines an inch to an inch and a half in length. 



Bark. Dark brown to ashy gray, fissured and broken into small 

 scales. Branchlets coated at first with thick pale tomentum, later 

 they become dark orange color, finally they become ashy gray. 



Wood. Bright reddish brown; heavy, hard, close-grained. Sp. 

 gr., 0.7585; weight of cu. ft., 47.57 Ibs. 



Winter Buds. Small, globular, chestnut brown. Inner scales 

 grow with the growing shoot becoming nearly an inch long before 

 they fall. 



Leaves. Alternate, simple, ovate to ovate-oblong, two to five 

 inches long, incisely lobed and sharply and finely serrate, except at 

 the base, gradually narrowing at the base and running into winged 

 petioles, acute or rarely rounded at the apex. Conspicuously retic- 

 ulate-veined, midrib broad and primary veins prominent. They 

 come out of the bud conduplicate, when full grown are thin gray 

 green, smooth above, but very downy beneath. In autumn they turn 

 orange and scarlet. Petioles winged, grooved, sometimes glandular. 

 Stipules linear, glandular, serrate, early deciduous. 



Flowers. May, June, later than the White Thorn. Perfect, white, 

 half an inch across, very ill scented, borne in broad, leafy, downy, 

 slender-branched cymes. 



Calyx. Urn-shaped, coated with pale tomentum, five-lobed ; 

 lobes lanceolate, serrate, acute, often glandular, finally reflexed, per- 

 sistent, imbricate in bud. 



Corolla. Petals five, obovate, erose, inserted in the calyx tube, 

 imbricate in bud. 



Stamens. Fifteen to twenty, inserted with the petals; filaments 

 thread-like ; anthers introrse, two-celled ; cells opening longitu- 

 dinally. 



Pistil. Ovary inferior, two to five carpels inserted at the bottom 

 of the calyx tube and united with it. 



