334 
IOWA ACADEMY OF SCIENCE Vor. XXIX, 1922 
2. P. Canadensis Canada S. White S. Black Hills Spruce 
Branches somewhat rising, the branchlets not drooping. Lvs. 
ashy green ; branchlets pale ashy yellow. Cones 2- 5 cm. long, the 
scales rounded. 
Pist. fls. about 2cm. long. Branchlets not hairy. Cones falling 
off at maturity (March-Apr.). 
Cult, common. 
Campus; nursery. 
N. B. to S. Dak. and northward. 
FI. Apr.-May. Fr. Oct. 
Note: Often planted for ornament and for windbreaks, but less dense 
than the preceding. A hardy strain from the Black Hills of S. Dak. is cult., 
as Black Hills Spruce. 
3. P. pungEns Piercing P. Colorado Blue Spruce 
Branches horizontal, the branchlets stiffly horizontal or rising. 
Lvs. very stiff, needle-pointed, bluish white on the sides. Twigs 
with pale yellow bark. 
Cones 1dm. long, hanging on a long time, the scales soft and 
thin, notched at margin. Branchlets glabrous. 
Cult, common. 
Campus. 
Col., Utah, Wyo. 
Note: The stiffest, and in its most waxy-blue forms, the most showy 
of evergreens ; very variable in color. Healthy, hardy, clothed with lvs. to 
the ground ; of fine conical form. P. Bngelmanni will doubtless be intro- 
duced ere long; distinguished by having branchlets downy. 
4. Abies Fir Balsam 
(The classical name) 
Cone-shaped evergreens with lvs. l-5cm. long, spirally arranged 
but spreading out in 2 rows, flat, paler beneath. 
Twigs with flat circular scars where the lvs. have fallen off. 
Bark with swollen sacs of resin (balsam). Foliage and resin 
pleasantly scented, especially in drying. Cones erect, the scales 
falling from the axis at maturity. Winter buds crowded and 
touching at ends of shoots. 
1. Evs. 2cm. long or less i. A. balsamea 
1. Lvs. 2.5-7cm. long 2 . A. concolor 
1. A. balsamea Balsam Fir Canada Balsam 
Lvs. short, very dark green, l-2cm. long, blunt. Tree slender 
and spirelike, thinly leafed. 
Pist. fl. violet colored; cones cylindric, 6-10cm. long, 2-3cm. 
thick. 
Cult, frequently. 
Nursery; Hazelwood. 
