Abies Concolor - Species

Species

As treated here, there are two subspecies; these are also variously treated at either the lower rank of variety by some authors, or as distinct species by others:

• Abies concolor subsp. concolor. Colorado white fir or Rocky Mountains white fir. In the United States, at altitudes of 1700–3400 m in the Rocky Mountains from southern Idaho south through Utah and Colorado to New Mexico and Arizona, and on the higher Great Basin mountains of Nevada and extreme southeastern California, and a short distance into northern Sonora, Mexico. A smaller tree to 25–35 m tall, rarely 45 m. Foliage strongly upcurved to erect on all except weak shaded shoots in the lower crown; leaves mostly 3.5–6 cm, and strongly glaucous on the upper side with numerous stomata. Tolerates winter temperatures down to about -40°C.

• Abies concolor subsp. lowiana (syn. A. lowiana). Low's white fir or Sierra Nevada white fir. In the United States, at altitudes of 900–2700 m (2,900-8,800 ft) from the Cascades of central Oregon south through California (Klamath Mountains, Sierra Nevada) to northern Baja California, Mexico. A larger tree to 40–60 m tall. Foliage flattened on lower crown shoots, the leaves often raised above the shoot on upper crown shoots but not often strongly upcurved; leaves mostly 2.5–5 cm, and only weakly glaucous on the upper side with few or no stomata. Tolerates winter temperatures down to about -30°C.