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 trom the end of the leaf-stem 
(digitate or palmately compound), as in the 
Horse Chestnut. 
A.—Leaves (not leaflets) set allernately* on the branches. 
Branches armed: 
With pairs of straight thorns ; leaflets equal-sided Gyantemicny: 
Branchlets and leaf-stems thickly set with bristle-like hairs with glands 
pbs OP GUS: a2 sees cocci a ae ee ee 
Branchilets and leaf-stems not glandular-hairy : 
Thorns pearly white; fruit-pods closely coiled in a spiral ..--.. 2... 
Thorns yellowish ; fruit-pods flattened (not coiled).............2-.. 
With short hooked prickles ; leaflets unequal-sided (unsymmetrical) .._... 
Branches unarmed: 
Leaflets evergreen ; fruit a pod (contracted between the beans) with red, 
Wwihite-scarred Deanses ass ee 
Leaflets deciduous; fruit not a pod: 
Leaflets uneqnal-sided and often not quite opposite on the leaf-stem.. 
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)..........--. 
Leaflets more than 3; fruit berry-like ora nut: 
Leaflets long-pointed; fruit a nut with a wrinkled shell. ........ 
Leaflets short: pointed : 
Mruic,berry-like, red. in ytlab Clusterses=ss- =e ae ae 
Fruit not berry-like—3 dark, shiny nuts in a 3-lobed husk....-.. 
B.—Leaves set opposite 3 on the branches. 
Wood with a large, white, soft pith; fruit (berries) black, but sities with 
bloom: clustered. see ee eee 
Wood with a small, dark, oe hard pith; fruit (seed a thin-winged 
key: 
- Leaflets 3 to 5; seeds (keys) in pairs, but separable: Box-elder.....-.. 
Leaflets more than 5; seeds (keys) single; ASHES: 
ibeatlets:smooth and oreen‘on both sides 22ers eee 
Leaflets 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 secds (keys) 14°t0,2 inches long ea sncsee ae ee 
Inner bark of branches not red ; young shoots and leaf-stems downy 
- (not rusty): . 
Mature seeds (keys) 4 to 1#anches long? 2... 2eeeeeece ae cee 

YUCCAS. 
(Trees with unbranched trunks and wood notin annual layers—a mingled mass of 
fibers. ] 
Leaves 1 to nearly 3 feet long: 
ihessthantaninch wide22 a2 4 se.) seisle n= = onan oe eee ee i 
More than 4 an‘inch wide (14 to 2 inches)= <==. 2) =" see area eee 88 

