Family Key 1] 
K. Fruit a cup containing an acorn; leaves often deeply lobed or cleft; 
primary lateral veins extending into the teeth; winter buds with more 
than 2 scales; terminal winter buds present. FAGACEAE (p. 124) 
KK. Fruits in a cone-like or ament-like cluster; leaves in most species 
shallowly if at all lobed; bud scales | to many; terminal winter buds 
present or none. 
L. Primary lateral leaf-veins extending into the teeth or lobes; seed 
a winged nutlet; calyx present; bracts thick in fruit. 
BETULACEAE (p. 122) 
LL. Primary lateral leaf-veins arching and uniting within the margins; 
seed hairy; calyx none; bracts thin in fruit. 
SALICACEAE (p. 117) 
II. Flowers not in aments. 
M. Leaves ovate, somewhat falcate, distinctly oblique at base, coarsely ser- 
rate, 3-veined from the base. Celtis in ULMACEAE (p. 126) 
MM. Leaves not as above in all the characters mentioned. 
N. Fruit dry, wing-margined. Ulmus in ULMACEAE (p. 126) 
NN. Fruit fleshy, not even angular. 
O. Petals 6 mm. or more long; stamens many; leaves usually distinctly 
serrate;. winter buds covered with scales. MALACEAE (p. 221) 
OO. Petals 5 mm. or less long; stamens 5; leaves entire or finely ser- 
rate; winter buds naked; taste of the bark characteristic. 
Rhamnus in RHAMNACEAE (p. 250) 
GROUP 5—Shrubs with alternate compound leaves 
A. Leaves evergreen, coriaceous, spine-toothed at margin, bunched at the stem tips; 
stems not prickly. Berberis in BERBERIDACEAE (p. 172) 
AA. Leaves deciduous or evergreen; the evergreen plants with leaves scattered along 
prickly stems and without spine-toothed leaf margins. 
B. ‘Twigs dark-green, sharply 4-angled, very long; leaflets 3, 2.5 cm. or less long, 
leaves not abundant; fruit a bean-like pod. | Cytisus in LEGUMINACEAE (p. 224) 
BB. ‘Twigs not dark-green, not angled; leaves and leaflets various; fruit not bean-like. 
C. Either vines, or else plants with prickly stems. RosAcEAE (p. 206) 
CC. Not vines; stems not prickly. 
DD. ‘Leaflets 7——3 1; fruit red. 
E. Leaflets 13—-31, acuminate; stem simple or very little branched; in- 
florescence conical, hairy; fruit with red hairs. ANACARDIACEAE (p. 247) 
EE. Leaflets 7—17, acute to obtuse; stem considerably branched; inflores- 
cence flat-topped, glabrous; fruit red, glabrous. 
. Sorbus in MALACEAE (p. 221) 
DD. Leaflets 3—7; fruit red or some other color. 
F. Leaflets subulate to linear, sharp-pointed. POLEMONIACEAE (p. 311) 
FF. Leaflets not subulate nor sharp-pointed. 
G. Leaflets 0.4—2.5 cm. long; either the plant silky-villous or the leaf- 
lets cuneiform. ROSACEAE (p. 206) 
GG. Leaflets 2.5—-7.5 cm. long; plant glabrous; leaflets not cuneiform. 
ANACARDIACEAE (p. 247) 
GROUP 6—Shrubs with alternate simple deciduous leaves and spiny or prickly branches 
A. Leaves palmately veined. hess 
B. Twigs 12—25 mm. thick; leaves 15—40 cm. wide; inflorescence terminal, con- 
ical, of very many flowers. Echinopanax in ARALIACEAE (p. 270) 
« 
