Quercus hypoleucoides, thesilverleaf oak or thewhiteleaf oak, is a North American species ofoak tree or shrub. It grows in the southwestern United States and northern Mexico.[4][5]
Quercus hypoleucoides, though usually seen as a shrub, can be found to be a full-sized tree, 9 metres (30 feet) tall in areas where it receives sufficient water.[6][7]
The tree produces its flowers in the spring as most plants do.[8] It grows in warm regions and is used as an ornamental due to its unusual foliage.[9]
Bark: Is dark gray in color. It is thin with shallow, lighter-colored fissures and narrow ridges.[8]
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.[8]
Leaves: Are alternate, evergreen, simple, and narrowly oblong to lanceolate. They are usually 5–10 centimetres (2 to 4 inches) 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.[8]
Fruits: Oblong acorn that is 1.5–2 cm (1⁄2–3⁄4 in) inch long. The cap is scaly bowl-shaped and covers one-third of the nut which ripens in 1 (or 2 seasons), maturing in early fall.[8]
Flowers:Q. hypoleucoides is amonoecious plant, with both male and female flowers growing on the same plant. This is opposed todioecious 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.[8]
Form: Though usually found as a shrub, given enough moisture it can become a medium-sized tree that reaches up to 18 m (60 ft) tall with a spreading round crown.[10]
Q. hypoleucoides can be distinguished from other oaks by its lanceolate leaves which are dark green on top but silver white on the lower surface.[6][7]
Its species name,hypoleucoides, means "white underneath", referring to the leaves.[6] It has been referred to asQuercus hypoleucaEngelm., anillegitimate name, and asQuercus confertifoliaTorr., not to be confused withQuercus confertifoliaBonpl.[3]
The species is commonly found in moist canyons and on ridges.[8] It also is found in coniferous forests and high elevated lands from 1,500–2,400 m (5,000 to 8,000 ft) above sea level.[6] Mountains of southern Arizona and New Mexico such as theSanta Catalina Mountains and theChiricahua Mountains, for example, have a pine-oak woodland at an elevation of roughly 1,710–2,160 m (5,700 to 7,200 ft). Here,Q. hypoleucoides can be found as well as other species of oak trees such as theQ. arizonica,Q. emoryi, andQ. rugosa.[11]
This species has acorns which are eaten by both squirrels and birds.[6] The taller trees also help to provide shade for animals below who need to get away from the strong rays of the sun.
It is a vigorous post-fire resprouter and will form a multi-stem shrub in areas of repeated fire.[12]
^abcdefCarter, Jack L.; Martha A. Carter; Donna J. Stevens (2003). "Shrubs".Common Southwestern Native Plants: An Identification Guide. Silver City, NM: Mimbres. p. 144.
^Peet, Robert K. (2000). "Forests and Meadows of the Rocky Mountains". In Michael G. Barbour, W. D. Billings (ed.).North American Terrestrial Vegetation (2 ed.). Cambridge, U.K.: Cambridge University Press. pp. 75–121.
.jpg)
