92 ROSACEAE. 



9. Calyx often persistent on the fruit. P. micromalus. 



Calyx absent from fruit. (Siberian crab). P. baccata. 



10. Calyx absent. (Orchard crab). P. baccataXMalus. 

 Calyx persistent on the fruit, n. 



11. Leaves not at all lobed. (Apple). P. Mains. 

 Leaves slightly crenately lobed. X P. Soulardi. 



12. Calyx persistent on the fruit. (American crab apples). 13. 

 Calyx absent from the fruit. Asiatic. P. Sieboldii. 



13. Leaves rather hastately few-lobed. P. coronaria. 

 Leaves not hastate. 14 



14. Flowers single. P. ioensis. 

 Flowers double. (Bechtel crab). P. ioensis plena. 



ARONIA. Chokeberry. 



Deciduous shrubs with rather slender subterete branches with 

 roundish homogeneous pith ; alternate appressed solitary ovoid 

 or oblong buds with about 3 exposed scales ; rather lanceolate 

 moderate serrate leaves with slender black glands on the midrib 

 above ; small low crescent-shaped leaf-scars with 3 bundle- 

 traces ; rather small cymose perfect polypetalous epigynous 

 flowers ; and small red or black berry-like pomes. 



1. Leaves glabrate : fruit black. A. melanocarpa. 

 Leaves pubescent beneath. 2. 



2. Fruit black-purple. A. atropurpurea. 

 Fruit red. A. arbutifolia. 



SORBUS. Mountain Ash. Rowan Tree. 



Deciduous small trees with rather soft pale or brown wood 

 with minute diffused ducts and tine medullary rays ; moderate 

 or rather stout terete twigs ; somewhat angled rather large pith ; 

 alternate narrowly crescent-shaped or transverse somewhat 

 raised leaf-scars with about 5 bundle-traces ; no stipule-scars ; 

 large appressed sessile buds with several scales ; alternate odd- 

 pinnate or simple petioled leaves with serrate blade or leaflets ; 

 perfect small polypetalons epigynous white flowers in compound 

 terminal corymbs ; and sitiall red or orange berry-like ponies. 

 i. Leaves compound. 2. 



Leaves simple. S. Aria. 



