''Pinus johannis'', the Johann's pine, is a

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

in the

pinyon pine The pinyon or piñon pine group grows in southwestern North America, especially in New Mexico, Arizona, and Utah. The trees yield edible nuts, which are a staple food of Native Americans, and widely eaten as a snack and as an ingredient in Ne ...

group, native to North America. The range extends from southeast

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

and southwest

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, south in

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

along the

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...

and the Sierra Madre Oriental to southern

Zacatecas , image_map = Zacatecas in Mexico (location map scheme).svg , map_caption = State of Zacatecas within Mexico , coordinates = , coor_pinpoint = , coordinates_footnotes = , subdivision_type ...

and San Luis Potosí. It occurs at moderate to high altitudes, from , in cool, dry climate conditions.

Description

''Pinus johannis'' is a small to medium-size

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

, often just a shrub, reaching tall and with a trunk diameter of up to . The bark is grey-brown, thin and scaly at the base of the trunk. The leaves ('needles') are in mixed fascicles of three and four, slender, long, and deep green to blue-green, with stomata confined to a bright white band on the inner surfaces. The

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

are globose, 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 6-12 fertile scales. The cones open to broad when mature, holding the

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s on the scales after opening. The seeds are long, with a thick shell, a white endosperm, and a vestigial wing; they are dispersed by the

Mexican jay The Mexican jay (''Aphelocoma wollweberi'') Etymology: ''Aphelocoma'', from Latinized Ancient Greek ''apheles-'' (from ἀφελής-) "simple" + Latin ''coma'' (from Greek ''kome'' κόμη) "hair", in reference to the lack of striped or banded ...

, which plucks the seeds out of the open cones. The jay, which uses the seeds as a major food resource, stores many of the seeds for later use; some of these stored seeds are not used and are able to grow into new trees. ''Pinus johannis'' is nearly dioecious: nearly all individuals produce either male or female cones only, and trees do not appear to change their sex expression over time.

History

''Pinus johannis'' is a recently described

, discovered by

Elbert L. Little Elbert Luther Little, Jr. (born October 15, 1907, in Fort Smith, Arkansas; died June 23, 2004) was an American botanist whose career spanned 70 years and largely concerned forest botany. Although he was born in Arkansas, and died in Oregon, he grew ...

in 1968 when comparing pinyons growing in Arizona with those of typical Mexican pinyon (''

Pinus cembroides ''Pinus cembroides'', also known as pinyon pine, Mexican pinyon, Mexican nut pine, and Mexican stone pine, is a pine in the pinyon pine group, native to western North America. It grows in areas with low levels of rainfall and its range extends ...

'') in Mexico; he described it as a

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

of Mexican pinyon, ''Pinus cembroides'' var. ''bicolor'', noting the very different stomatal placing on the leaves; it also differs in needle number, with 3–4 per fascicle, rather than 2–3; in the cones having thinner scales; and in having a denser, more rounded crown. Further research by the French botanist Marie-Françoise Robert-Passini, the American botanists Dana K. Bailey and Frank G. Hawksworth and others, has shown that it is better treated as a distinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

. Although often occurring together with Mexican pinyon, it is reproductively isolated from that by its

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...

being a month to two months later in summer, rather than in spring, thereby preventing hybridisation. As Robert-Passini and Bailey & Hawksworth were working in different areas at about the same time, it was raised to species rank twice, first as ''Pinus johannis'' by Robert-Passini (naming it after her husband Jean) examining specimens in the Sierra Madre Oriental in Mexico, and then later as ''Pinus discolor'' by Bailey & Hawksworth examining specimens in the northern Sierra Madre Occidental in Arizona. There are slight differences between the plants in the two ranges; those in the eastern being more shrubby and with larger cones than those in the western range, and also differences in the

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on n ...

composition; they are though generally very similar and recognition of both as separate species from each other does not appear warranted. Some botanists also still include ''P. johannis'' in Mexican pinyon as a variety or even not distinguished at all, accounting for reports of "Mexican pinyon" in Arizona and New Mexico. This is despite the two frequently occurring together at the same sites with no hybridisation. ''Pinus johannis'' is most closely allied to Orizaba pinyon (''

Pinus orizabensis ''Pinus orizabensis'', the Orizaba pinyon, 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'' subsp. ''orizabensis'' D.K.Baile ...

'') and Potosi pinyon (''

Pinus culminicola ''Pinus culminicola'', commonly known as Potosí pinyon or Potosí Piñón, is a pine in the pinyon pine group, native and endemic to northeast Mexico. The range is highly localised, confined to a small area of high summits in the northern Sierra ...

''), with which it shares the leaf structure with the stomata confined to the inner faces; it differs from the former in the smaller cones and seeds, and from the latter in fewer needles per fascicle (3–4 vs 5).

Uses

The edible

pine nut Pine nuts, also called piñón (), pinoli (), pignoli or chilgoza (), are the edible seeds of pines (family Pinaceae, genus ''Pinus''). According to the Food and Agriculture Organization, only 29 species provide edible nuts, while 20 are trad ...

seeds are collected in Mexico to a small extent. The white-glaucous inner surfaces of the needles make it a very attractive small tree, suitable for parks and large

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

References

External links

Pinetum.org – Photos of ''Pinus johannis'' tree and foliage (scroll half-way down)

{{Taxonbar, from=Q3506525 johannis Trees of the Southwestern United States Trees of the South-Central United States Flora of the Southwestern United States Flora of Northwestern Mexico Flora of Northeastern Mexico Flora of Sonora Flora of Zacatecas Flora of San Luis Potosí Flora of Arizona Flora of New Mexico Flora of the Sierra Madre Occidental Flora of the Sierra Madre Oriental Edible nuts and seeds Garden plants of North America Drought-tolerant trees Dioecious plants Plants described in 1978 Flora without expected TNC conservation status