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, Arborvitse 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 



