520 FLORA. 



dull, oblanceolate to broadly obovate, 4-8 cm. long; fruit oval, about I cm. long. 

 Mo. to La. April-May. 



6. Crataegus prunifolia (Marsh.) Pers. PLUM-LEAVED THORN. Similar to 

 broad-leaved forms of C. Crus-galli, the leaves oval to obovate, acutish. serrate 

 nearly to the base; 5-7 cm. long, 3-5 cm. wide, pubescent beneath, at least when 

 young; pedicels and calyx pubescent; flowers and globose pome about I cm. broad. 

 Mo. Perhaps not the original Mespilus prunifolia Marsh. 



7. Crataegus collina Chapm. ROUND-FRUITED THORN. A small tree, the 

 young foliage and the inflorescence pubescent. Leaves obovate, mostly acute, finely 

 serrate, tapering into the short petiole; flowers 8-10 mm. broad; styles 5; fruit 

 hard, globular, about i cm. in diameter. Va. to Ga. and Mo. April-May. 



8. Crataegus punctata Jacq. LARGE-FRUITED THORN. (I. F. f. 1993.) 

 A shrub or small tree, with horizontal, thorny branches. Thorns 2-5 cm. long, 

 often branched; leaves slender-petioled, obovate, obtuse or short pointed at the 

 apex and irregularly serrate or serrulate, cuneate at the base, nearly glabrous 

 above, pubescent or at length glabrous beneath. 5-8 cm. long, rarely lobed, veins 

 straight, conspicuous'; flowers 1-2 cm. broad ; calyx- lobes linear, entire ; styles 

 mostly 3 ; fruit globose or oval, red or yellow, 1.5-2.5 cm. in diameter. In 

 thickets, Quebec and Ont. to N. H., Ga., west to Iowa. May. 



Crataegus punctata canescens Britton. Lower leaf-surfaces, petioles, peduncles and 

 pedicels densely whitish-tomentose. Vt. to Ont., Penn. and Ohio. 



9. Crataegus flabellata (Spach) Rydb. FAN-LEAVED THORN. Leaves 

 flabellate, broadest above the middle, cuneate at the base, thin and usually with a 

 few scattered hairs beneath when young, sharply and irregularly incised serrate, 

 glabrous, firm and shining above when old, 6-IO cm. long, slender-petioled; thorns 

 5 cm. long or more; fruit globose, 1-1.5 cm. in diameter. Quebec to Me., R. I., 

 the N. W. Terr, and Mont. 



10. Crataegus cordata (Mill.) Ait. WASHINGTON THORN. (I. F. f. 1994.) 

 A tree, 5-15 m. high. Spines slender, 2-5 cm. long ; leaves slender-petioled, 

 broadly ovate, generally sharply 3-7-lobed and serrate, acute or acuminate at the 

 apex, truncate or cordate at the base, 28 cm. long; flowers 8-12 mm. broad ; 

 styles 5; fruit bright red, depressed-globose, 4-6 mm. high. In woods and 

 thickets, Va. to Ga., III. and Tenn. ; escaped from cultivation in southern N. J. 

 and Penn. March-May. 



11. Crataegus Eggerti Britton. EGGERT'S THORN. Foliage sparingly pu- 

 bescent when young, glabrous when mature. Thorns 3-6 cm. long; leaves ovate- 

 orbicular, dull green above, pale beneath, sharply and irregularly serrate, or 

 somewhat lobed, mostly truncate or subcordate at the base, acute or acutish at the 

 apex, slender-petioled, 5-12 cm. long, and about as wide; flowers 2-2.5 cm - broad; 

 bracts large, very glandular; fruit subglobose, large, sometimes nearly 2 cm. in 

 diameter, glaucous. In dry soil, Iowa to Mo. and Kans. April-May. 



12. Crataegus Oxyacantha L. HAWTHORN. WHITE OR MAY THORN. 

 (I. F. f. 1995.) A shrub or tree. Thorns stout, numerous; leaves slender-petioled, 

 glabrous on both sides or pubescent when young, sharply 3~7-lobed, broadly ovate 

 or slightly obovate, broadly cuneate at the base, 2-5 cm. long; flowers 1-1.5 cm - 

 broad, white or pink; calyx-lobes ovate; styles 1-3; fruit globose or globose ovoid, 

 about 6 mm. high. Along roadsides and in thickets, sparingly escaped from cul- 

 tivation. May June. 



13. Crataegus viridis L. SOUTHERN THORN. (I. F. f. 1996.) A small 

 tree, often without spines. Leaves slender-petioled, ovate to lanceolate or some- 

 what obovate, glabrous, or pubescent in the axils of the veins beneath, sharply ser- 

 rate and usually somewhat lobed, mostly acute at each end, 2-8 cm. long; flowers 

 1-1.5 cm - broad; calyx-lobes lanceolate; styles commonly 5; fruit globose or oval, 

 about 6 mm. high, persistent into the winter, 6-8-seeded. Mo. and Kans. to La., 

 Tex., S. Car. and Fla. March-April. 



14. Crataegus nitida Engelm. SHINING THORN. Similar to C. viridis, 

 but often a larger tree, the leaves thicker, larger, ovate to oval, and more shining 

 above. Flowers about 2 cm. broad; fruit globose, I cm. in diameter, or a little 

 more, 4-5 -seeded, glaucous. 111., Mo. and Ark. May. \C. viridis nitida Engelm.] 



15. Crataegus Porteri Britton. PORTER'S THORN. A shrub, wholly gla- 



