102 SILVA OF NORTH AMERICA. 
CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES. 
PLEIANDR2. 
Aments terminal on leafy branches; stamens 3 or more, their filaments free and 
hairy at the base ; scales deciduous from the pistillate ament before the ripening 
of the fruit. Bark dark and deeply furrowed, or in No. 8 nearly smooth. 
Leaves narrowly lanceolate, long-pointed, often faleate, green on both surfaces, 
glabrous at maturity 2. 6. ee ee eee eee ee ee 
Leaves lanceolate or ovate-lanceolate, silvery white on the lower surface. . . 2. 
Leaves lanceolate, acuminate, pale, often silvery white, and glabrous or puberu- 
lous on the lower surface . . . . . . . ee ee ee ee ee 
Leaves lanceolate or ovate-lanceolate, acuminate, pale and glaucous on the lower 
surface... . 6 ew we ee eee ee ee ee AB“ 
Leaves lanceolate or oblong-lanceolate, acute or acuminate, blue-green on the 
upper surface, pale or glaucous on the lower . . . . «. - - «~~ - « O. 
Leaves lanceolate, taper-pointed, often pale or glaucous on the lower surface, 
their petioles glandular. . . 2. «© 2 © 2 1 ee we we ew ew ew ee 6 
Leaves linear-lanceolate or oblong-lanceolate, often falcate, silvery white on the 
lower surface, persistent during the winter . . . . . . ..... 7. 
Leaves lanceolate, long-pointed, coriaceous, dark green and lustrous, their 
petioles glandular . ©. 1 1. ee ee ee ee ee eee 8B 
DIANDR&. 
Stamens 2, their filaments glabrous or slightly hairy at the base, free or more or 
less united in Nos. 16,18, and 19. Bark usually smooth, or deeply fissured in 
No. 11. 
Aments terminal and axillary on leafy branches. 
Leaves linear-lanceolate, usually green on both surfaces . . . . . .. . Y 
Leaves lanceolate or linear-lanceolate, villous on the lower surface with lustrous 
pale hairs 
Leaves linear-lanceolate, pale gray-green, and puberulous . : 
Aments terminal on abbreviated branches, their leaves often reduced to deciduous 
bracts ; scales colored at the apex, persistent under the fruit. 
Leaves oblong-obovate or oblong-elliptical, conspicuously reticulate-venulose, 
dull green on the upper surface, glaucous or silvery white and pubescent on 
the lower : 
Leaves oblong, oblong-obovate, or lanceolate, glaucous or silvery white on the 
lower surface 
Leaves lanceolate or oblanceolate, acuminate, dark green on the upper surface, 
pale on the lower . ; 
Leaves lanceolate or oblanceolate, long-pointed, pale and often silvery white on 
the lower surface . . . 15. 
Leaves oblanceolate or lanceolate-oblong, dark green on the upper surface, pale 
or glaucous and pubescent or puberulous on the lower . . 16. 
Leaves oblong-obovate, acute or acuminate or rounded at the apex, yellow- 
green on the upper surface : 
Leaves elliptical-oblong, obovate, or oblanceolate, dark green on the upper sur- 
face, and glaucous on the lower . - 4 
Leaves oblong or oblong-obovate, yellow-green and glabrous or tomentose on 
the upper surface, pale or glaucous and tomentose on the lower . . 19. 
Leaves oblong-obovate to oblanceolate, usually acute or acuminate, coated 
below with lustrous white tomentum . 20. 
. 10. 
. 11. 
. 12. 
. 13. 
. 14. 
. 17. 
- 18. 
MN 
S. 
S. 
S. 
. NIGRA. 
. WARDI. 
- OCCIDENTALIS. 
- AMYGDALOIDES. 
- LEHVIGATA. 
- LASIANDRA. 
. BONPLANDIANA. 
- LUCIDA. 
- FLUVIATILIS. 
- SESSILIFOLIA. 
TAXIFOLIA. 
BEsBIANA. 
DISCOLOR. 
S. CORDATA, var. MACKENZIFANA. 
MissourRIENSIS. 
S. LASIOLEPIS. 
S. 
NUtTTALLII. 
S. Preert. 
S. 
HOooKERIANA. 
S. SrrcHENsIs. 
SALICACE. 
