Picea breweriana, known as Brewer's spruce, Brewer spruce, Brewer's weeping spruce, or weeping spruce, is a species of spruce native to western North America, where it is one of the rarest on the continent. The specific epithet breweriana is in honor of the American botanist William Henry Brewer.
Description
Brewer's spruce is a large evergreen conifer growing to tall, exceptionally 54 m, and with a trunk diameter of up to 1.5 m. The bark is thin and scaly, and purple-gray in color. The crown is very distinct, distinguished by level branches with vertically pendulous branchlets up to , each branch forming a 'curtain' of foliage. The pendulous foliage only develops when the tree grows to about 1.5–2 m tall; young trees smaller than this (up to about 10–20 years old) are open-crowned with sparse, level branchlets. The shoots are orange-brown, with dense short pubescence about 0.2 millimeters long and very rough with pulvini 1–2 mm long.
The leaves are borne singly on the pulvini, and are needle-like but with a blunt tip, have shown that Picea breweriana has a basal position in the Picea clade,
Because of its slow growth, Brewer's spruce cannot compete with other much faster-growing trees like Douglas-fir. It is also susceptible to wildfire due to its thin bark and pendulous foliage, and therefore is seen to occur in exposed sites with poor, rocky soils, often at high elevation, where competition with other fire-sustaining conifers is reduced. It may also be found sporadically in open montane forests alongside conifer species adapted to similar conditions such as white fir, red fir, or mountain hemlock. The shrub species huckleberry oak and deer oak are other common associates.
The species is known to host several species of pathogens and parasites, including the root rot Heterobasidion annosum, the dwarf-mistletoe Arceuthobium campylopodum, and the adelgid Adelges cooleyi.
Cultivation
Outside its native range, P. breweriana is a highly-valued ornamental tree in gardens, particularly in Great Britain and Scandinavia, where it is appreciated for its dramatically pendulous foliage.
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File:Picea brewerianafullform.JPG|On a ridge above Bear Lake, Siskiyou Mountains, Ca.
File:Picea breweriana foliage.JPG|Foliage of a young tree, ridge above Bear Lake, Ca.
File:Picea breweriana RHu.JPG|Picea breweriana in a garden
File:Picea breweriana - weeping twigs2.jpg|The weeping twigs
File:Picea breweriana2.jpg|Foliage
File:Picea breweriana leaf1.jpg|Close-up foliage
File:Picea breweriana (flowers).jpg|Fresh female cones
File:Picea breweriana cones01.jpg|Mature male cones & developing female cone
File:Picea breweriana mature cone.jpg|Mature cone
File:Mature Picea breweriana, Royal Botanic Garden, Edinburgh.jpg|Mature Picea breweriana, Royal Botanic Garden, Edinburgh
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References
External links
- Catalogue of Life: Picea breweriana