1. Primary veins of the larger leaves running to the sinuses as well as to the points 

 of the lobes 1. C. spathulata. 



1. Primary veins of the leaves running only to the points of the lobes, very rarely 



with some running to the sinuses (2) 



2(1). Thorns short and stout, rarely slender or more than 2 cm. long; fruits blue 

 or black at maturity (3) 



2. Thorns usually slender, typically more than 4 cm. long, rarely absent; fruits 



red, yellow or remaining green at maturity (4) 



3(2). Leaves mostly abruptly pointed or rounded at the apex, lustrous above; 



fruit blue and glaucous at maturity; in eastern Texas 



2. C. hrachyacantha. 



3. Leaves mostly acute to acuminate at the apex, dull-green above; fruit grading 



from purple to black, lustrous but not glaucous; in northwestern 

 Texas and New Mexico 3. C. rivularis. 



4(2). Flowers 2 to 5 in simple clusters; stamens 20 to 25 4. C. opaca. 



4. Flowers usually more numerous, as many as 20 in simple or compound cymes 



or corymbs; stamens 5 to 20 (5) 



5(4). Leaves of flowering branchlets usually rhombic to somewhat obovate or 

 sometimes ovatish, typically narrowed at base, relatively thin, dull- 

 green above; fruit becoming soft or mellow with age; nutlets 3 to 5 

 7. C. viridis. 



5. Leaves of flowering branchlets mostly narrowly obovate or oblong-obovate, 



seldom over 2-3 cm. wide, mostly thick or firm, glossy above; fruit 

 remaining hard and often green at maturity; nutlets commonly 1 

 to 3 (6) 



6(5). Foliage and inflorescence glabrous or essentially so 5. C. pyracanthoides. 



6. Foliage and inflorescence more or less pubescent or somewhat scabrous 



6. C berberifolia. 



1. Crataegus spathulata Michx. Pasture haw. 



Shrub or tree 5-7 m. high, with stoutish usuafly thorny horizontal branchlets 

 and thin scaly or smooth gray bark; leaves of flowering branchlets narrowly obo- 

 vate, mostly 1-2 cm. long and to 1 cm. wide, with several coarse rounded teeth or 

 small lobes above the middle or near the apex, gradually narrowed to the entire 

 base, firm, glabrous at maturity, glossy above, with strongly ascending or nearly 

 parallel obscure veins; petioles one fourth to half as long as the blades; flowers 

 6-8 mm. across, numerous in compact glabrous corymbs; stamens about 20; 

 anthers pale-yellow; calyx lobes deltoid, entire, persistent on fruit; fruit subglobose, 

 4-7 mm. thick, red, with thin mellow flesh and 3 or 4 nutlets. C. microcarpa 

 Lindl. 



Sandy or sandy clay woods, palmetto marsh area where occasionally flooded, 

 fencerows and pastures in e. Okla. and e. Tex., fruiting Oct.-Nov.; from Fla. to 

 Tex. and Okla., n. to Va. and s. Mo. 



2. Crataegus hrachyacantha Sarg. & Engelm. Bluberry hawthorn. 



Tree to 15 m. high; branchlets light-green and slightly pubescent early in the 

 season, soon becoming glabrous and ultimately ashy-gray in color, armed with 

 numerous short stout somewhat curved spines that are rarely to 2 cm. long; leaves 

 oblong-oblanceolate to somewhat rhombic, abruptly pointed or rounded at the 

 apex, gradually narrowed to the cuneate base, crenulate-serrate above with minute 

 incurved glandular teeth, somewhat pubescent at first; mature leaves subcoriaceous, 

 glabrous, lustrous, dark-green, to 5 cm. long and 25 mm. wide; flowers numerous 

 in crowded glabrous corymbs, on slender pedicels, about 8 mm. wide; sepals short, 

 triangular, narrowed to a gland-tipped apex; stamens 15 to 20; anthers yellow; 



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