158 



Leaves compound: ie., composed of leaflets which are arranged in pairs 



(opposite) along a leaf-stem (pinnately com- 

 pound) as in peas and beans; or, a number of 

 leaflets radiating from the end of the leaf-stem 

 (digitate or palmately compound), as iu the 

 Horse Chestnut. 

 A. — Leaves (not leaflets) set aliernalelij^ on the branches. 

 Branches armed : 



With pairs of straight thorns; leaflets equal-sided (symmetrical): 

 Branchlets and leaf-stems thickly set with bristle-like hairs with glands 



at the tips ^ 37 



Branchlets and leaf-stems not glandular-hairy : 



Thorns pearly white ; fruit-pods closely coiled in a spiral 40 



Thorns yellowish ; fruit-pods flattened (not coiled) 39 



Witli short hooked pricldes ; leaflets unequal-sided (unsymmetrical) 41 



Branches unarmed : 



Leajlets evergreen ; frnit a pod (contracted between the beans) with red, 



white-scarred beans 38 



Leaflets deciduous ; fruit not a pod : 

 Leaflets unequal-sided and often not quite opposite on the leaf-stem.. 33 

 Leaflets equal-sided and opposite on the leaf-stem : 

 Leaflets 3 ; fruit in clusters, a flat, light-colored seed with a wing all 



around (resembles an Elm-seed) 28 



Leaflets more than 3 ; fruit berry-like or a nut : 



Leaflets long-pointed; fruit a nut with a wrinkled shell 66 



Leaflets short- pointed : 



Fruit, berry-like, red, in flat clusters 52 



Fruit not berry-like — 3 dark, shiny nuts in a 3-lobedhusk 32 



B. — Leaves set opposite 3 on the branches. 

 Wood with a large, white, soft pith ; fruit (berries) black, but white with 



bloom, clustered 56 



Wood with a small, dark, rather hard pith ; fruit (seed a thin-winged 

 key: 



Leaflets 3 to 5 ; seeds (keys) in pairs, but separable : Box-elder 36 



Leaflets more than 5 ; seeds (keys) single ; Ashes : 



Leaflets smooth and green on both sides 60 



licaflets smooth and green above, but more or less downy on the under- 

 side : 

 Inner bark of the branches red ; young shoots and leaf-stems rusty- 

 velvety : 



Mature seeds (keys) H to 2 inches long 59 



Inner bark of branches not red ; young shoots and leaf-stems downy 

 (not rusty) : 

 Mature seeds (keys) f to If inches long 58 



YUCCAS. 



[Trees with unbranched trunks and wood not in annual layers — a mingled mass of 



libers. ] 



Leaves 1 to nearly 3 feet long : 



Less than -^ an inch wide 87 



More than ^ an inch wide (1-^ to 2 inches) 88 



