Engelmann Spruce
Encyclopedia
Picea engelmannii is a species of spruce
native to western North America
, from central British Columbia
and southwest Alberta
, southwest to northern California
and southeast to Arizona
and New Mexico
; there are also two isolated populations in northern Mexico
. It is mostly a high altitude mountain
tree, growing at 900-3650 m altitude, rarely lower in the northwest of the range; in many areas it reaches the alpine tree line.
Picea engelmannii is a medium-sized to large evergreen
tree
growing to 25-40 m tall, exceptionally to 65 m tall, and with a trunk diameter of up to 1.5 m. The bark
is thin and scaly, flaking off in small circular plates 5-10 cm across. The crown is narrow conic in young trees, becoming cylindric in older trees. The shoots are buff-brown to orange-brown, usually densely pubescent, and with prominent pulvini. The leaves
are needle-like, 15-30 mm long, rhombic in cross-section, glaucous blue-green above with several thin lines of stomata, and blue-white below with two broad bands of stomata.
The cones
are pendulous, slender cylindrical, 4-8 cm long and 1.5 cm broad when closed, opening to 3 cm broad. They have thin, flexible scales 15-20 mm long, with a wavy margin. They are reddish to dark purple, maturing pale brown 4–7 months after pollination. The seed
s are black, 2-3 mm long, with a slender, 5-8 mm long pale brown wing.
(treated as varieties
by some authors, and as distinct species by others) occur:
Picea engelmannii, Engelmann Spruce, hybridises and intergrades extensively with the closely related White Spruce
found further north and east in the Rocky Mountains, and to a lesser extent with the closely related Sitka Spruce
where they meet on the western fringes of the Cascades.
, harvested for paper
-making and general construction. Wood from slow-grown trees at high altitude has a specialised use in making acoustic guitar
s and harp
s. It is also used to a small extent as a Christmas tree
.
have destroyed millions of Englemann Spruce trees.
Spruce
A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...
native to western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, from central British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and southwest Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, southwest to northern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and southeast to Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
; there are also two isolated populations in northern 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...
. It is mostly a high altitude mountain
Mountain
Image:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
tree, growing at 900-3650 m altitude, rarely lower in the northwest of the range; in many areas it reaches the alpine tree line.
Description
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
growing to 25-40 m tall, exceptionally to 65 m tall, and with a trunk diameter of up to 1.5 m. The bark
Bark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
is thin and scaly, flaking off in small circular plates 5-10 cm across. The crown is narrow conic in young trees, becoming cylindric in older trees. The shoots are buff-brown to orange-brown, usually densely pubescent, and with prominent pulvini. 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....
are needle-like, 15-30 mm long, rhombic in cross-section, glaucous blue-green above with several thin lines of stomata, and blue-white below with two broad bands of stomata.
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 pendulous, slender cylindrical, 4-8 cm long and 1.5 cm broad when closed, opening to 3 cm broad. They have thin, flexible scales 15-20 mm long, with a wavy margin. They are reddish to dark purple, maturing pale brown 4–7 months after pollination. 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 are black, 2-3 mm long, with a slender, 5-8 mm long pale brown wing.
Subspecies and hybrids
Two geographical subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
(treated as varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....
by some authors, and as distinct species by others) occur:
- Picea engelmannii subsp. engelmannii (Engelmann Spruce). All of the range except as below.
- Picea engelmannii subsp. mexicana (Mexican Spruce). Two isolated populations on high mountains in northern MexicoMexicoThe 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...
, on the Sierra del Carmen in CoahuilaCoahuilaCoahuila, 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...
(Sierra Madre OrientalSierra Madre OrientalThe 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...
) and on Cerro Mohinora in Chihuahua (Sierra Madre OccidentalSierra Madre OccidentalThe Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
). Engelmann Spruces of the Madrean sky islandsMadrean sky islandsThe Madrean Sky Islands are enclaves of Madrean pine-oak woodlands, found at higher elevations in a complex of small mountain ranges in southern and southeastern Arizona, southwestern New Mexico, and northwestern Mexico. The sky islands are surrounded at lower elevations by the Sonoran and...
mountains in the extreme southeast of Arizona and southwest of New Mexico also probably belong to this subspecies, though this is disputed.
Picea engelmannii, Engelmann Spruce, hybridises and intergrades extensively with the closely related White Spruce
White Spruce
Picea glauca is a species of spruce native to boreal forests in the north of North America, from central Alaska east to Newfoundland, and south to northern Montana, Minnesota, Wisconsin, Michigan, upstate New York, Vermont, New Hampshire, and Maine; there is also an isolated population in the...
found further north and east in the Rocky Mountains, and to a lesser extent with the closely related Sitka Spruce
Sitka Spruce
Picea sitchensis, the Sitka Spruce, is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 95 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter...
where they meet on the western fringes of the Cascades.
Uses
Engelmann Spruce is of economic importance for its woodWood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
, harvested for paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
-making and general construction. Wood from slow-grown trees at high altitude has a specialised use in making acoustic guitar
Guitar
The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with...
s and harp
Harp
The harp is a multi-stringed instrument which has the plane of its strings positioned perpendicularly to the soundboard. Organologically, it is in the general category of chordophones and has its own sub category . All harps have a neck, resonator and strings...
s. It is also used to a small extent as a Christmas tree
Christmas tree
The Christmas tree is a decorated evergreen coniferous tree, real or artificial, and a tradition associated with the celebration of Christmas. The tradition of decorating an evergreen tree at Christmas started in Livonia and Germany in the 16th century...
.
Predators
Outbreaks of spruce beetlesDendroctonus rufipennis
The Spruce Beetle is a species of bark beetle native to British Columbia, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, the Yukon, and Maine. They are known to destroy forests of spruce trees including Englemann, White, Sitka, and Colorado blue spruce...
have destroyed millions of Englemann Spruce trees.