46 PINACEAE, 
PicEA, Spruce. 
Conical evergreen trees with rather soft yellowish-white 
ductless wood with scattered resin-passages (exceptionally 
brown and with transversely clustered passages); moderate 
fluted often hairy twigs; small homogeneous pith; 5-ranked 
usually 4-sided needle-like leaves on raised bases bearing the 
angled leaf-scars with a single bundle-trace; no stipule-scars; 
ovoid scaly more or less resinous buds; monoecious catkin-like 
or cone-like naked flowers; and pendent cones with persistent 
thin scales each covering 2 winged seeds. 
1. Leaves small (scarcely 15 mm.), green, blunt. P. orientalis. 
Leaves mostly longer (20-25 mm.), acute. 2. 
2. Leaves green. 3. 
Leaves pale or whitened. 4. 
3. Not weeping. P. excelsa. 
Weeping. P. excelsa pendula. 
4. Leaves merely pale. 5. 
Leaves very glaucous. P. pungens. 
5. Odor balsamic: cones large (10-18 cm.). P. excelsa. 
Odor fetid: cones small (scarcely 5 cm.). P. canadensis. 
Tsuca. Hemlock Spruce. 
Evergreen percurrent trees with ductless brownish wood 
without resin-passages; slender fluted twigs; small continuous 
pith; alternate somewhat raised minute half-round leaf-scars 
with a single bundle-trace; no stipule-scars; sessile ovoid buds 
with several exposed scales; very small oblong or lanceolate 
sometimes serrulate short-petioled flat leaves whitened beneath ; 
monoecious catkin- or cone-like naked flowers; and small ovoid 
cones, each thin scale covering 2 winged seeds. 
i, frees: 2. 
Prostrate shrub, T. canadensis nana. 
2. Not weeping. 3. 
Weeping. T. canadensis pendula. 
3. Conical or oblong. 4. 
Round-topped. T. canadensis globosa. 
