6 PRIifCIPLES OF AMERICAI^ FORESTRY. 



LENGTH OF TIME THAT LEAVES OF CONIFERS REMAIN 

 ON TREES IN MINNESOTA. 



Botanical Name. 



Common Name. 



Year of Falling. 



Pinus strobus 



Pinus flexilis 



Pinus resinosa 



Pinus divaricata 



Pinus ponderosa scopulorum. 



Pinus sylvestris 



Pinus laricio austriaca 



Pinus montana pumila 



Larix laricina 



Larix europea 



Picea canadensis 



Picea mariana 



Picea pungens 



Picea engelmanni 



Picea excelsa 



Tsuga canadensis 



Pseudotsuga taxifolia 



Abies halsamea 



Abies concolor 



Thuja occidentalis 



Juniperus virginiana 



Juniperus communis 



White Pine 



Western White Pine , 



Norway Pine 



Jack Pine 



BuU Pine 



Scotch Pine 



Austrian Pine 



Dwarf Pine 



Tamarack 



European Larch. . . . 



White Spruce 



Black Spruce 



Blue Spruce 



Engelmann Spruce. . 



Norway Spruce 



Hemlock 



Douglas Spruce 



Balsam Fir .' 



White Fir 



Arborvitae 



Red Cedar 



Dwarf Juniper 



2d and 3d. 

 5th and 6th. 

 4th and 5th. 

 2d and 3d. 

 3d and 4th. 

 3d. 



4th and 5th. 

 5th, 6th, and 7th. 

 1st winter. 

 1st winter. 

 4th and 5th. 

 4th and 5th. 

 6th and 7th. 

 5th and 6th. 

 5th. 



2d and 3d. 

 5th. 

 5th. 

 5th. 



4th and 5th. 

 5th and 6th. 

 5th and 6th. 



Flowers are parts of the plant especially modified for the 

 reproduction of the plant by seed. Both sexual organs 

 may be located together in the same flower, as those of the 

 Basswood, Mountain Ash, and Cherry; or in separate 

 flowers on the same plant, as those of the Birch, Oak, and 

 Black Walnut; or they may be separate on entirely different 

 plants, as in the Willow, Poplar, Box-elder, and Ash. 



The Fruit, botanically defined, is the seed-containing 

 area, derived from a single flower. As used in nursery 

 practice the term is generally applied to seeds having a 

 fleshy covering or an adjoining fleshy part. 



The Seed, botanically defined, is the ripened ovule, but 

 as the term is used in nursery practice it often includes the 

 ovary and other parts that may be attached to it. What 



