ai>cd 4 e a f* KEY, BASED UPON LEAVES. 7 



h2 Shrubs or very small trees. . .DWARF CHINQUAPIN OAK (Q. prinoides) . 

 d^ Margin both serrate or serrate -dentate and lobed in the same Ivs., thpugh the 

 lobed Ivs. may be on vigorous shoots only, and the latter Ivs, are not 

 considered in these further descriptions. 

 e Fruit a small pome (apple) 



f With 1-5 bony, 1-seeded nutlet-like carpels; email trees and shrubs with 



thorny branches; Ivs. 

 g Obovate (large ones more elliptical) entire, cuneate b., rounded or acute 



a.; petioles short, winged above and glandless; 

 h Leaves lustrous dark-green ab., thick; fr. globose-oblong, % in., dull 



red; nutlets 1-3 COCK-SPUR THORN (Crataegus crus-galli) . 



h2 Leaves dull gray-green ab., more membranaceous ; fr. subglobose, %-l 

 in., dull red or yellow with white dots. 



DOTTED THORN (C. punctata) . 



g2 Obovate-oblong, wider and short cuneate b., petioles longer and winged ab. 



h Irregularly serrate-dentate, acute or blunt-pointed and slightly, if at all, 



lobed, dark green and smooth ab. ; fr. scarlet or orange, l / 4 in. or 



less; nutlets usually 5 SOUTHERN THORN (C. viridis). 



h2 Crenate-serrate or with short crenate toothed lobes, rounded or obtuse 

 a.; fr. oblong-globose, % in., dark red or orange, black dotted, with 



2-3 nutlets .MARGARETTA THORN (C. Margaretta). 



h3 With short acute-toothed lobes or doubly serrate-dentate, obtuse to 

 acute a., pubescent bn. 2-5 in.; petioles glandular; fr. oblong- 

 globose, % in.; nutlets 2-3 with ventral cavities. 



PEAR THORN (C. tomentosa). 



g3 Obovate-orbicular, rounded or obtuse a., coriaceous, coarsely and irregu- 

 larly serrate-dentate, or very slightly lobed; thorns 2%-4 in.; fr. 

 lustrous crimson, ^-^ in., subglobose, on erect stems; nutlets with 

 deep ventral cavities. . . .LONG-SPINE THORN (Crataegus macracantha) . 

 g* Leaves broad-ovate; 



h Waxy-coated, slightly 5-angled and flattened subglobose, apple-green 

 becoming purplish red; Ivs. subcordate b., acute, with 3 or 4 pairs 



short pointed lobes, thickish WAXY THORN (C. pruinosa) . 



h 2 Fruit pubescent at least at the ends, 



i Subglobose, %-l in., in small drooping villous clusters; calyx-lobes 

 large and deciduous; nutlets 4 or 5; Ivs. truncate or subcordate 

 b., with appressed pubescence ab., pubescent bn. 



RED-FRUITED THORN (C, mollis). 



12 Obo void-oblong, in erect compact clusters with prominent and per- 

 sistent calyx-lobes and tube; Ivs. rounded b., acute or obtuse a. 



CHAMPLAIN THORN ( C. Champlainensis ) . 

 h3 Smooth and lustrous, about % in.; Ivs. scabrous ab. ; fr. 



1 Orange red with pale dots, obovoid, calyx-lobes enlarged and per- 

 sistent; Ivs. thickish RED-FRUITED THORN (C. submolis). 



i2 Bright scarlet with dark dots; Ivs. membranaceous. 



SCARLET THORN (C. pedicellata) . 



gs Triangular-ovate, 1^-3 in., truncate b., acute or acuminate a., lustrous 

 dark green ab., coarsely serrate-dentate and incisely 3-5-lobed. 



WASHINGTON THORN (C. cordata). 



