How to Identify Soft Pine Tree Needles
- 1). Count the needles within a single bundle. The leaves are arranged in clusters called fascicles, bound by a sheath that may or may not persist at the base. Most pines have fascicles of two, three or five needles; most soft pines have five. (The singleleaf pinon of the American Southwest and Mexico is the only member of the genus with only one needle per bundle.) The eight native pines of the Pacific Northwest, for example, can be classified according to fascicle in the following way: Typically, lodgepole pines have a pair of needles per bundle; ponderosa, Jeffrey and knobcone pines have three; and five are found in each fascicle of western white, whitebark, sugar and limber pines---which are all soft pines.
- 2). Measure the needle. While this can be a useful diagnostic in conjunction with others, leaf length is too variable and there is too much overlap among species for it to be a foolproof criterion. Among the soft pines of the western U.S., the needles of sugar and western white pines are often longer than those of whitebark and limber pines---up to 10cm in the former pair, to 7cm in the latter.
- 3). Note other needle characteristics that can guide identification. What color is the needle? Looking closely and employing touch as well, how many edges does it have? Consider the distribution of the stomata, which will appear as light flecks on the needle exterior. Seek these features in a taxonomic key or a field guide's text descriptions.