POMACEAE. 5 J 9 



Fruit 10-12 mm. in diameter, glaucous or pruinose. 

 Leaves firm, shining. 



Fruit globose ; western. 14. C. nitida. 



Fruit pyriform ; eastern. 15. C. Porteri. 



Leaves thin, dull. 16. C. pruinosa. 



surfaces or teeth of the leaves, pedicels and calyx pubescent or glandular. 

 Leaves deeply pinnately incised ; fruit 4-6 mm. long. 17. C. apiifolia. 



Leaves serrate or lobed ; fruit 6-25 mm. long. 

 Leaves glabrous, or nearly so. 



Leaves, or most of them, truncate or cordate at the base. 



1 8. C. coccinea. 



Leaves, or most of them, narrowed at the base. 

 Fruit 8-14 mm. in diameter. 



Fruit globose to oval; leaves firm in texture. 



Bractlets and calyx very glandular. 19. C. rotundifolia. 

 Bractlets and calyx pubescent. 20. C. occidentals. 



Fruit pyriform ; leaves thin. 21. C. tenui folia. 



Fruit only 6-8 mm. in diameter. 22. C. macracantha. 



Leaves pubescent, especially along the veins beneath. 



Leaves ovate-orbicular, mostly truncate or cordate at base. Fruit 1.5- 



2.5 cm. in diameter; red. 23. C. mollis. 



Leaves ovate to oval, mostly cuneate or narrowed at the base. 

 Fruit globose or depressed -globose. 



Veins not prominent on the lower leaf-surfaces. 



24. C. Biltmoreana. 



Veins very straight and prominent. 25. C. campestris. 



Fruit oval to oblong. 



Fruit dull red, over i cm. long. 26. C. tomentosa. 



Fruit bright red, i cm. long or less. 27. C. Chapmani. 



Fruit pyriform. 28. C. pyriformis. 



* * Corymbs I-7-flowered. 



Calyx-lobes not incised ; petioles and leaf-serrations very glandular. 



29. C.flava. 



Calyx-lobes deeply incised ; petioles and leaf-serrations little or not at all glandular. 

 Leaves obovate or spatulate, obtuse. 30. C. uniJJord t 



Leaves oval, mostly acute at both ends. 31. C. Vailiae. 



1. Crataegus Crus-galli L. COCKSPUR THORN. NEWCASTLE THORN. 

 (I. F. f. 1991.) A shrub or small tree, the branches spreading. Thorns numerous, 

 slender, 510 cm. long; leaves coriaceous, shining above, obovate or oblanceolate, 

 obtuse or abruptly acuminate at the apex, cuneate at the base, 2-5 cm. long, sharply 

 serrate; flowers about 12 mm. broad; calyx-lobes linear-lanceolate; styles usually 

 1-3; fruit globose or slightly pear-shaped, about 12 mm. long. In thickets, Que- 

 bec to Manitoba, N. H., Fla. and Tex. May-June. 



2. Crataegus brevispina (Dougl.) Farwell. DOUGLAS THORN. A small 

 tree. Foliage glabrous or nearly so. Leaves obovate, unequally serrate or some- 

 what lobed, cuneate or narrowed at the base, 4-8 cm. long, the petiole about one- 

 fourth the length of the blade ; thorns 1.5-3 cm - l n gl flowers about 2 cm. wide; 

 calyx-lobes ovate, obtuse, rarely glandular; fruit globose, purple-black, 1-1.5 cm - * n 

 diameter. Mich, to Br. Col., Colo, and Ore. May- June. [C. Douglasii Lindl.] 



3. Crataegus spathulata Michx. SMALL-FRUITED HAW. (I. F. f. 1992.) 

 A shrub or small tree. Spines 2-5 cm. long; leaves fascicled, coriaceous, shining 

 above, rather dull beneath, spatulate, obtuse and crenate or with 23 lobes at the 

 summit, entire and cuneate at base, almost sessile, 2-4 cm. long; flowers about 8 

 mm. broad ; calyx-lobes ovate ; styles commonly 5 ; fruit red, globose, 4 6 mm. 

 Vmg. In thickets, Va. to Fla., Mo. and Tex. May-June. 



4. Crataegus Brownii Britton. ADDISON BROWN'S THORN. Glabrcus 

 throughout. Leaves obovate or oval -obovate, obtuse, or obtusish at the apex, 

 cuneate-narrowed at the base, irregularly crenate, with distinctly rounded teeth, 

 slender-petioled, 4-6 cm. long : pedicels slender; bracts linear, very glandular; 

 flowers about 1.5 cm. broad ; calyx-segments linear-lanceolate. Va. and W. Va. 

 May. Type from Buchanan. Va. 



5. Crataegus berberifolia T. & G. BARBERRY-LEAVED THORN. Similar 

 to C. Crus-galli, but the young leaves, pedicels and calyx densely pubescent. 

 Thorns slender, 2-5 cm. long; mature leaves pubescent with scattered hairs, rather 



