92 ROSACEAE, 
9. Calyx often persistent on the fruit. P. micromalus. 
Calyx absent from fruit. (Siberian crab). FP, paccata. 
10. Calyx absent. (Orchard crab). P. baccata&X Malus. 
Calyx persistent on the fruit. 11. 
11. Leaves not at all lobed. (Apple). P. Malus. 
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. melanocagpa. 
Leaves pubescent beneath. 2. 
2. Fruit black-purple. A. atropurpurea. 
Fruit red. . A. arbutifolia. 
Sorsus, Mountain Ash. Rowan Tree. 
Deciduous small trees with rather soft pale or brown wood 
with minute diffused ducts and fine 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 polypetalous epigynous white flowers in compound 
terminal corymbs; and small red or orange berry-like pomes. 
1. Leaves compound. 2. 
Leaves simple. SB UAria. 
