Quercus hypoleucoides

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Quercus hypoleucoides
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Fagales
Family: Fagaceae
Genus: Quercus
Section: Quercus
Species: Q. hypoleucoides
Binomial name
Quercus hypoleucoides[1]
A.Camus (1932)
Quercus hypoleucoides range map 1.png
Natural range of Quercus hypoleucoides
Synonyms[2]
  • Quercus confertifolia Torr.
  • Quercus hypoleuca Engelm. 1876 not Miq. 1858 nor Kotschy ex A.DC. 1864 nor Gand. 1890

Quercus hypoleucoides, the silverleaf oak or the whiteleaf oak is a North American species of trees or shrubs in the beech family. It grows in the southwestern United States and northern Mexico.[3][4]

Quercus hypoleucoides, though usually seen as a shrub, can be found to be a full-sized tree, 30 feet (9 meters) tall in areas where it receives lots of water. Quercus hypoleucoides can be distinguished from other oaks by its lanceolate leaves which are dark green on top but silver white on the lower surface.[5][6]

Description[edit]

Quercus hypoleucoides produces its flowers in the spring as most plants do.[7] It grows in warm regions and is used as an ornamental due to its unusual foliage.[8] Its species name, hypoleucoides, means "white underneath" and also happens to be the main way that it is distinguished from other oak trees. This species has acorns which are eaten by both squirrels and birds and even at times by humans. However before it is safe for people to eat, the tannic acid must first be leached out due to its toxic qualities.[5]

  • Bark: Is dark gray in color. It is thin with shallow, lighter-colored fissures and narrow ridges.[7]
  • Twig: Reddish brown in color and are broadly triangular with a sharp point. Are slender to moderate, generally with white fuzz. The end buds are clustered.[7]
  • Leaves: Are alternate, evergreen, simple, and narrowly oblong to lanceolate. They are usually 2 to 4 inches (5–10 cm) long, with edges revolute. Occasionally there are a few shallow teeth, a narrow pointed tip, and a leathery texture. They are usually a shiny yellow-green on top and white or silvery on the bottom.[7]
  • Fruits: Oblong acorn that is 1/2 to 3/4 inch long. The cap is scaly bowl-shaped and covers 1/3 of the nut which ripens in 1 (or 2 seasons), maturing in early fall.[7]
  • Flowers: Quercus hypoleucoides is a monoecious plant and therefore both male and female flowers grow on the same plant. This is opposed to dioecious plants where male flowers and female flowers grow on separate trees. The male flowers form long drooping catkins that are yellow-green in color. The female flowers have very small spikes in leaf axils that appear with the leaves.[7]
  • Form: Though usually found as a shrub, given enough moisture it can become a medium sized tree that reaches up to 60 feet (18 meters) tall with a spreading round crown.[9]

Distribution[edit]

Quercus hypoleucoides is commonly found in moist canyons and on ridges.[7] It also is found in coniferous forests and high elevated lands from 5,000 to 8,000 feet (1500–2400 meters) above sea level.[5] Mountains of southern Arizona and New Mexico such as the Santa Catalina Mountains and the Chiricahua Mountains, for example, have a pin-oak woodland at an elevation of roughly 5700 to 7200 feet (1710–2160 meters). Here, Quercus hypoleucoides can be found as well as other species of oak trees such as the Quercus arizonica, Q. emoryi, and Q. rugosa.[10]

Specimens have also been collected south of the international frontier, in Sonora, Chihuahua, Coahuila, and Sinaloa.[4]

Fire ecology[edit]

Quercus hypoleucoides is a vigorous post-fire resprouter and will form a multi-stem shrub in areas of repeated fire. [11]

Quercus hypoleucoides resprouting following fire

Uses[edit]

Quercus hypoleucoides is has been used for ornamental purposes. Its leaves have a unique contrast due to the very white, silver color of the bottom. Its acorns are a source of food for squirrels and birds. The taller trees also help to provide shade for animals below who need to get away from the strong rays of the sun.

References[edit]

  1. ^ "Quercus Hypoleucoides A. Camus Silverleaf Oak". United States Department of Agriculture. Retrieved 10 April 2012. 
  2. ^ The Plant List, Quercus hypoleucoides A.Camus
  3. ^ Biota of North America Program 2014 county distribution map
  4. ^ a b SEINet, Southwestern Biodiversity, Arizona chapter
  5. ^ a b c Carter, Jack L.; Martha A. Carter; Donna J. Stevens (2003). "Shrubs". Common Southwestern Native Plants: An Identification Guide. Silver City, NM: Mimbres. p. 144. 
  6. ^ "Vascular Plants of the Gila Wilderness". Western New Mexico University. Retrieved 10 April 2012. 
  7. ^ a b c d e f g "Silverleaf Oak". Flora of North America. EFloras. 
  8. ^ "Quercus Hypoleucoides A. Camus". Lady Bird Johnson Wildflower Center. The University of Texas at Austin. Retrieved 10 April 2012. 
  9. ^ "Silverleaf Oak Fagaceae Quercus Hypoleucoides A. Camus". VT Forest Biology and Dendrology. Virginia Tech Department of Forest Resources and Environmental Conservation. 
  10. ^ Peet, Robert K. (2000). "Forests and Meadows of the Rocky Mountains". In Michael G. Barbour, W. D. Billings. North American Terrestrial Vegetation (2 ed.). Cambridge, U.K.: Cambridge University Press. pp. 75–121. 
  11. ^ Schwilk, D.W..; Gaetani, M.; Poulos, H.M (2013). "Oak bark allometry and fire survival strategies in the Chihuahuan Desert Sky Islands, Texas, USA". PLoS One. 8 (11). doi:10.1371/journal.pone.0079285. 

External links[edit]