ROSACEAE. 95 



posed scales ; moderate serrate petioled leaves ; moderate perfect 

 polypetalous epigynous white flowers ; and small berry-like pur- 

 ple pomes. 



1. Leaves always glabrous, closely serrate. A. laevis. 

 Leaves for a time woolly beneath. 2. 



2. Leaves closely serrate (teeth 10 to i cm.). A. canadensis, 

 Leaves more distantly toothed (teeth S to i cm.). 3. 



3. Leaves rather acute, persistently tomentose. A. sanguinea. 

 Leaves very obtuse, quickly glabrous. A. alnifolia.- 



CRATAEGUS. Haw. Red Haw. 



Deciduous shrubs or small trees, usually with axillary spines ; 

 hard usually brownish wood with very minute diffused ducts 

 and fine medullary rays ; rounded twigs ; somewhat angular 

 homogeneous pale pith ; alternate not raised crescent-shaped 

 small leaf-scars with 3 bundle-traces ; round-ovoid solitary ses- 

 sile buds with several fleshy often red scales ; simple usually 

 toothed or lobed stalked leaves frequently clustered on spurs ; 

 moderate perfect epigynous white or rosy flowers usually in 

 terminal corymbs; and small apple-like fruits with bony core. 

 A hopelessly complex genus, the following common. 



1. Leaves spatulate or cuneate-obovate, rarely large or lobed. 2. 

 Leaves elliptical or obovate. 4. 



Leaves round or ovate. 6. 



2. Leaves glabrous, glossy above, spines long. C. Crus-galli. 

 Leaves pubescent beneath. 3. 



3. Leaves dull, with strong veins. C. punctata. 

 Leaves glossy above, fruit often downy. C. tomentosa. 



4. Spines curved : nutlets with concave sides. C. macracantha. 

 Spines straight : nutlets with flat sides. 5. 



5. Spines long : leaves rather thin and dull. C. tomentosa. 

 Spines short : leaves rather firm or glossy. C. viridis. 



6. Leaves deeply lobed. 7. 

 Leaves at most shallow-lobed. 9. 



7. Veins running from midrib both to sinuses and lobes. 8. 

 Veins running from midrib to lobes only. C. Phaenopyrum. 



