LEGUMINOSAE, 109 
in spring and the smaller in tangential waves in the fall 
growth, and moderate medullary rays; moderate zig-zag round- 
ish twigs; roundish continuous pith; alternate raised leaf-scars, 
for a time concealing the small superposed rounded buds and 
with 3 bundle-traces; bristle-like or spinescent stipules; no end- 
buds; typically odd-pinnate leaves with entire stipellate leaflets; 
showy perfect papilionaceous white or rosy flowers in axillary 
racemes; and rather small flat few-seeded legumes. 
1. Twigs neither glandular nor bristly. 2. 
Twigs bristly. 9. 
Twigs with sticky glands, not bristly. R. viscosa. 
2. Tree round or ovoid. 3. 
Tree pyramidal, R. Pseudacacia pyramidalis. 
3. Unarmed. 4. 
With stipular spines. 5. 
4. Branching open. R. Pseudacacia inermis. 
Branching compact. R. Pseudacacia umbraculifera. 
. Leaves mostly of only 1 leaflet. R. Pseudacacia monophylla. 
Leaves distinctly compound. 6. . 
6. Weeping R. Pseudacacia pendula. 
Not weeping. 7. 
on 
7. Leaves green. 8. 
Leaves yellow. R. Pseudacacia aurea. 
8. Flowers white. . R. Pseudacacia. 
Flowers rosy. R. dubia. 
g. Without sticky glands. R. hispida. 
With both glands and bristles. R. neo-mexicana. 
CoLuTeA. Bladder Senna. 
Deciduous shrubs with more or less shredding bark; 
rounded or angular twigs; rather angular homogeneous pale pith ; 
alternate small somewhat raised crescent-shaped leaf-scars with 
I or usually 3,5 or 7 bundle-traces inasingle series; more or less 
persistent soft stipules above the leaf-scars; round-ovoid soli- 
tary sessile small buds with 2-4 exposed scales; odd-pinnate 
leaves with moderately small entire short-stalked leaflets; rather 
