ALASKA: The Sitka spruce does not grow well outside of the cool moist foggy climate of the Pacific Northwest. A substitute species is grown to represent Alaska in the in the Grove of State Trees – Alaska cedar (Cupressus nootkatensis)
Alaska cedar was called Chamaecyparis nootkatensis for a long time, but it is now clear that it is not closely related to the other species of Chamaecyparis. There is still some controversy about how to classify it, and it is sometimes included in the genus Callitropsis or Xanthocyparis. Alaska cedar is another tall forest tree of the foggy coastal region of the Pacific Northwest, growing from Alaska south to northern California. While Alaska cedar grows together with Sitka spruce, it is more adaptable to a variety of conditions. It can be cultivated well in British gardens. Here in the District of Columbia, it can be grown if given adequate moisture during summer droughts.
Look for: Tiny overlapping scale-like leaves, branchlets drooping, Cones are ¼ inch long, round, and turning brown after two years on the tree.
ARIZONA: The blue palo verde is a desert species which cannot withstand the winters in the District of Columbia. A substitute species has been chosen to represent Arizona in the Grove of State Trees – Arizona cypress (Cupressus arizonica)
Although it is also an arid-adapted species, the Arizona cypress has proved remarkably adaptable outside of the arid desert uplands of its native habitat. Arizona cypress is used frequently as an ornamental in the southeastern United States, and it is valued for its dark green to bluish-colored foliage. A deep silver-blue color has been selected in some cultivars. A variety of Arizona cypress also produces attractive cinnamon-colored bark which peels in the manner of a crapemyrtle.
Look for: Conifer with scaly foliage, dark green to silver-blue; small spherical cones.
FLORIDA: Cultivation of the cabbage palmetto might be attempted outdoors in the District of Columbia if given a very sheltered spot, which is not available in our Grove. A substitute species has been chosen to represent Florida in the Grove of State Trees – Baldcypress (Taxodium distichum)
Baldcypress is a characteristic plant of southern swamplands. It is the dominant tree in Florida’s Big Cypress National Park. However, cypress swamps may be found as far north as Maryland, Missouri and Illinois. In cultivation the tree can tolerate a wide range of soils, but Baldcypress is best known as a swamp tree, growing in stagnant pools, and forming wide buttressed trunks, together with woody “knees” projecting from the water. The knees are outgrowths from the tree’s roots.
Look for: Straight upright growth habit, with age forming a buttressed base; soft small needles, about ½ inch long, falling during the winter; spherical cones which fall apart into sections when mature.
SOUTH CAROLINA: Cultivation of the cabbage palmetto might be attempted outdoors in the District of Columbia if given a very sheltered spot, which is not available in our Grove. A substitute species has been chosen to represent South Carolina in the Grove of State Trees – Swamp chestnut oak (Quercus michauxii)
Swamp chestnut oak is a large forest tree native to the southeastern United States. In South Carolina it is most prevalent along the coastal plain. As its name suggests, it is common in low-lying areas along river bottoms and flood plains. However it is not tolerant of continuous flooding. The leaves may turn a bronzy red in the fall.
Look for: Large tree to 80 feet tall; leaves simple, pale on the undersides, 4 to 8 inches long, with undulate margins; acorns 1 to 1 ½ inches long, with a scaly cup covering 1/3 of the nut.
HAWAII: The tropical candlenut cannot withstand winters in the District of Columbia. A substitute species has been chosen to represent Hawaii in the Grove of State Trees - Mamane (Sophora chrysophylla)
Mamane is a native Hawaiian tree, found on all but two of the Hawaiian Islands, and native nowhere else in the world. It can be common especially in forests and shrublands at high elevations. Mamane’s tolerance of a cool high elevation climate offers hope it may be cultivated here, though it must be considered experimental.
Look for: small tree or shrub, leaves compound with 6 – 10 pairs of leaflets, each up to two inches long. Flowers yellow, shaped like a pea-flower, in clusters at the end of the stems; fruit a narrow bean pod looking like beads on a string.
ALABAMA: The loblolly pine (Pinus taeda) is grown in the National Grove of State Trees to represent Alabama. Loblolly pine was chosen to represent a “Southern pine” prior to the legislation designating longleaf pine as the Alabama state tree. Loblolly pine is one of the most important pines used in southern pine plantations. It can tolerate a wide range of soils, and it is adept at growing in old depleted fields. Its wood is not as strong or as durable as wood of the longleaf pine. Nevertheless, loblolly wood has many uses in general construction applications.
Look for: pine tree with needles up to 9 inches long, in clusters of three, light green and somewhat twisted; cones 2 to 6 inches long.
KENTUCKY: The Kentucky coffee tree (Gymnocladus dioicus) was the state tree of Kentucky for eighteen years, and during that time these trees were planted in the National Grove of State Trees to represent Kentucky. The Kentucky coffee tree is a large tree in the bean family. The large seeds are toxic when raw, but at one time were roasted and used to make a bitter drink vaguely like coffee. The heavy and coarse-grained timber is very durable and resistant to the weather.
Look for: large-growing tree with irregular branches emerging at wide angles from the trunk; very rough gray bark; huge bipinnately-compound leaves, to 36 inches long, with leaflets up to two inches long; flowers dioecious, cream-colored, on inflorescences up to 12 inches long; large thick and hard bean pods containing large brown seeds.
Last Updated August 11, 2006 1:33 PM
URL = http://www.usna.usda.gov/Gardens/collections/treesubstitutes.html
August 11, 2006 1:33 PM