Fir

The fir can be classified within the genus abies and can be broken down into about 40 species of trees. Abies is a Latin word for an Old World species. They are native to North America, Central America, Africa, Europe, and Asia. They are gymnosperms and are evergreen trees that are are mostly located in upland areas.

Anatomy
Abies are evergreen trees that are most readily identified by their cones, which point upward rather than hanging down like other conifers. Abies have a single straight trunk with regularly spaced branch whorls. Whorls are a circle or spiral formed by branches. Whorls are produced at the rate of one whorl per year. This helps out because it is sometimes possible to determine the age of a tree. For example, if the tree was 50 years old it would have 50 branch whorls. The branches are also regular, with a single terminal and two lateral shoots produced each year at the tip of most active branches.

Reproduction
Firs are monoecious (both sexes) and produces female cones high in the crown, and clusters of male cones in a zone below. Female cones are borne singly or in groups of two, or rarely, up to five, on the upper side of one year old twigs. Male cones are borne in clusters of up to 30 or more on the undersides of branches. Seven developmental stages have been identified for female cone, beginning with bud swelling, and ending with cone shattering. A period of early rapid growth followed by pollen receptivity. The cone growth is generally completed by middle of August of the same year it started.

Ecology
The best specimens are found in deep rich soils with a short cool growing season and abundant annual precipitation, mainly as snow. North American firs are cut for pulpwood and lumber. They grow on large plantations, for Christmas trees. They are also grown as ornamentals. Species of abies frequently have a pleasant odor. Their foliage has been used as a stuffing material for pillows.

Related References

 * Fir Wikipedia
 * Fir Trees
 * Fir Tree
 * Abies USDA