Pinus culminicola, commonly known as Potosi Pinyon, is a pine

Pine

Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

 in the pinyon pine

Pinyon pine

The pinyon pine group grows in the southwestern United States and in Mexico. The trees yield edible pinyon nuts, which were a staple of the Native Americans, and are still widely eaten...

 group, native and endemic to northeast Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. The range is highly localised, confined to a small area of high summits in the northern Sierra Madre Oriental

Sierra Madre Oriental

The Sierra Madre Oriental is a mountain range in northeastern Mexico.-Setting:Spanning the Sierra Madre Oriental runs from Coahuila south through Nuevo León, southwest Tamaulipas, San Luis Potosí, Querétaro, and Hidalgo to northern Puebla, where it joins with the east-west running Eje Volcánico...

 in Coahuila

Coahuila

Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...

 and Nuevo León

Nuevo León

Nuevo León It is located in Northeastern Mexico. It is bordered by the states of Tamaulipas to the north and east, San Luis Potosí to the south, and Coahuila to the west. To the north, Nuevo León has a 15 kilometer stretch of the U.S.-Mexico border adjacent to the U.S...

, and only abundant on the highest peak, Cerro Potosí

Cerro Potosí

Cerro El Potosí is the highest mountain in the Sierra Madre Oriental mountain range of northeast Mexico. It is located in the state of Nuevo León, about 80 km south of Monterrey....

 (3713 m). It occurs at very high altitudes, from 3000-3700 m, in cool, moist subalpine climate conditions.

Description

It is a medium-size shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

, reaching 1.5-5 m tall and with a trunk diameter of up to 25 cm. The bark is grey-brown, thin and scaly at the base of the trunk. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 ('needles') are in fascicles of five, slender, 3-5.5 cm long, and deep green to blue-green, with stomata confined to a bright white band on the inner surfaces.

The cones

Conifer cone

A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...

 are globose, 3-4 cm long and broad when closed, green at first, ripening yellow-brown when 16–18 months old, with only a small number of thin, fragile scales, typically 6-14 fertile scales. The cones open to 4-6 cm broad when mature, holding the seed

Seed

A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s on the scales after opening. The seeds are 9-12 mm long, with a thick shell, a white endosperm

Endosperm

Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...

, and a vestigial 1-2 mm wing; they are dispersed by the Clark's Nutcracker

Clark's Nutcracker

Clark's Nutcracker , sometimes referred to as Clark's Crow or Woodpecker Crow, is a passerine bird in the family Corvidae. It is slightly smaller than its Eurasian relative the Spotted Nutcracker . It is ashy-grey all over except for the black-and-white wings and central tail feathers...

 and Mexican Jay

Mexican Jay

The Mexican Jay, Aphelocoma wollweberi, formerly known as the Gray-breasted Jay, is a New World jay native to the Sierra Madre Oriental, Sierra Madre Occidental, and Central Plateau of Mexico. It reaches north to eastern Arizona, western New Mexico and western Texas in the United States...

, which pluck the seeds out of the open cones. The jays, which uses the seeds as a major food resource, store many of the seeds for later use, and some of these stored seeds are not used and are able to grow into new plants.

History

Because of its isolation on a handful of remote mountain summits, Potosi Pinyon escaped discovery until 1959. It differs from most other pinyon species in needle number, with 5 per fascicle, rather than 1-4, and in its consistently shrubby stature. It is most closely related to Johann's Pinyon

Johann's Pinyon

Pinus johannis, the Johann's Pinyon, is a pine in the pinyon pine group, native to North America. The range extends from southeast Arizona and southwest New Mexico, United States, south in Mexico along the Sierra Madre Occidental and the Sierra Madre Oriental to southern Zacatecas and San Luis Potosí...

 and Orizaba Pinyon

Orizaba Pinyon

The Orizaba Pinyon, Pinus orizabensis, is a pine in the pinyon pine group, endemic to central Mexico. It is considered also as a sub-species of Pinus cembroides which is classified as Pinus cembroides orizabensis...

, like them having the leaf stomata confined to the inner faces; it also differs from the latter in its smaller cones and seeds. Like these two, the white-glaucous inner surfaces of the needles make it a very attractive slow-growing shrub, suitable for small garden

Garden

A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

s.

Like other pinyons, the pine nut

Pine nut

Pine nuts are the edible seeds of pines . About 20 species of pine produce seeds large enough to be worth harvesting; in other pines the seeds are also edible, but are too small to be of great value as a human food....

seeds are edible, but the inaccessibility of the plants prevents significant collection for food.