| Pinus leiophylla | |
|---|---|
 | |
| Pinus leiophylla subsp.chihuahuana, Bird Rock,Chiricahua National Monument,Arizona | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Pinaceae |
| Genus: | Pinus |
| Subgenus: | P. subg.Pinus |
| Section: | P. sect.Trifoliae |
| Subsection: | P. subsect.Australes |
| Species: | P. leiophylla |
| Binomial name | |
| Pinus leiophylla | |
 | |
| Natural range | |
Pinus leiophylla, commonly known asChihuahua pine,[2]smooth-leaf pine,[3][4] andyellow pine[4] (inMexico,tlacocote andocote chino), is atree with a range primarily in Mexico, with a small extension into theUnited States in southeast Arizona and southwestNew Mexico. The Mexican range extends along theSierra Madre Occidental andSierra Madre del Sur fromChihuahua toOaxaca, from 29° North Lat. to 17°, between 1600 and 3000 meters altitude. It requires about a rainfall 600 to 1000 mm a year, mostly in summer. It tolerates frosts in winter.
This member of familyPinaceae grows to the height of 20–30 m (66–98 ft) with a trunk diameter of 35–80 cm (14–31 in). The needles are in bundles of three to five, 5–10 cm (2–4 in) long, or rarely to 15 cm or 6 in, and are a bright glossy green to yellowish-green. The cones are ovoid, 4–7 cm (1+1⁄2–2+3⁄4 in) long, or rarely to8 cm or3+1⁄4 in, and borne on a1–2 cm (1⁄2–3⁄4 in) long stalk; they are unusual in taking about 30–32 months to mature, a year longer than most otherpines. The bark is gray-brownish, and fissured.
There are two subspecies (treated by some botanists as distinct species, by others as just varieties):
This species often grows in mixed in stands with several other pines and/orjunipers, in Arizona most often withApache Pine andAlligator Juniper, but also grows in pure stands. Its habitat is prone to wildfire, and the species shows some adaptations unusual among pines to cope with this; if the crown is destroyed by fire, the trunk, protected by its thick bark, will send out new shoots to re-grow a new crown. The only other pines to do this arePitch Pine (P. rigida) andCanary Island Pine (P. canariensis). As none of these are species particularly closely related to each other, the adaptation has probably arisen independently in each, an example ofconvergent evolution.
The wood of thePinus leiophylla is hard, dense and strong. It is used for construction, firewood, and railroad ties. InSouth Africa andQueensland, Australia there are big extensions of this tree planted. It is planted commercially inKenya,Malawi,Zimbabwe,Zambia at high altitudes.
