TREES OF MINNESOTA. 
PINACEAE. PINE FAMILY. 
Trees or shrubs with resinous juice. Leaves commonly 
needle-shaped or awl-shaped, and mostly evergreen. Flowers 
monoecious or sometimes dioecious, in catkins or cones, destitute 
of calyx and corolla. The pollen grains have lateral air sacs 
which buoy them up in the air, and they are occasionally carried 
hundreds of miles by the wind. Fruit either a woody cone with 
distinct scales, as in the pines, spruces, Arborvitee and Larch, or 
a somewhat berry-like cone with fleshy coherent scales, as in the 
Red Cedar. 
Genus PINUS. 
Leaves of two kinds; the primary ones, linear or scale like, 
deciduous: the secondary forming the ordinary foliage ever- 
green, from slender buds, in clusters of two, three or five 
together, each cluster surrounded by a sheath of thin mem- 
branous scales. Flowers appear in the spring, monoecious; the 
staminate in scaly catkins clustered at the base of the new 
growth; the pistillate in scaly catkins borne on the twigs of the 
preceding season, becoming scaly cones at maturity. Each scale 
is in the axil of a bract, and bears a pair of ovules adhering to 
its inner face, which peel off as the scale expands at matur- 
ity. Fruit a woody cone, maturing in the autumn of the second 
year. Cotyledons three to twelve, linear. We have only three 
native species in this state. 
Pinus strobus. White Pine. Weymouth Pine. 
Leaves soft, in clusters of five, about three to four inches long, 
falling at the end of the second or during the third season; sheath 
