Another common tree which has been used extensively as a landscaping tree in our area is Sweetgum, Liquidambar styraciflua. There are 2 native Liquidambar species in the US, which belong to the Witch-Hazel family, Hamamelidacea (recently treated as Altignaceae). Sweetgum grows straight and tall, 50 to 100 feet in height, with a conical crown. Its bark is gray, and furrowed into ridges, and not especially wide at 1-3 feet in diameter. Sweetgum is a deciduous tree with bright green maple-like palmate leaves 3 to 6 inches in length. I had mistaken this tree for a maple (Acer sp.) for some time due to the similar leaf structure which become reddish yellow in the fall. Its flowers are tiny greenish red ball-like clusters, male stamens and female pistils separate. The fruit created from pollinated female flowers, are spiky 1 inch drooping woody-brown balls which contain many seeds. These “gumballs” persist on the tree into the winter when the tree has become dormant, and superficially resemble Sycamore fruits (Platanus sp.) The gum or sap of this tree which can be found in the furrows of the bark was used medicinally and as a chewing gum substitute. The leaves give off a pleasant, sweet odor when crushed, which is another identifying characteristic.
Thuja is a genus of evergreen coniferous trees belonging to the Cypress Family, Cuppressaceae. There are only 5 species of Thuja worldwide, 2 from North America and 3 from Asia. In the Pacific Northwest Coast region of the US, Western Redcedar (Thuja plicata) is an important member of coastal and interior forests, especially in Washington and British Columbia. This species has played a very important role to native Americans, who had varied uses for the tree in their mostly fiber based economy.
Thuja can vary in size, from only 20 feet in ornamental settings to well over 200 feet in old growth forests. All species have soft,stringy, reddish brown bark which can be an easy identifying feature. Their leaves are scale like and found in 4 rows along its stem. Their foliage has a distinctive smell when crushed. Male cones are very small and borne on the end of twigs. Female cones start out small and grow to ½ inch in size, maturing in 6-8 months.
In our region of Lake of the Pines, Thuja species are commonly referred to as Arborvitae, or Tree of Life. Arborvitae can grow several feet per year when young. makes an excellent ornamental tree for homeowners, often used as hedges or barrier trees to provide privacy. It generally grows to be a mid sized tree, up to 50 feet. “Green Giant” Thuja is a popular cultivar for its use as a fast growing privacy screen, and its deer resistance. It has soft scale like leaves, very similar in structure and smell to other Cypress trees, and could be easily misidentified for juniper and/or cedar leaves.
Birch trees can be found planted within the Lake of the Pines community, which belong to the Birch Family, Betulaceae. Also within this family is Sierra Alder, Alnus rhombifolia, a small tree found growing from perennial streams in the Sierra Nevada, although not within Lake of the Pines. Birch are attractive trees, 50-70’ tall and 1-2’ wide with white, papery bark. Native to most other areas north and east of California on the continent, Birch species are propagated here for their ornamental value. Birch have ovate leaves with saw toothed margins, 2-4” long. Their simple alternate leaves are dark green above and lighter green below, and turn yellow in the autumn before falling. Birch trees are monoecious, with male catkins yellowish and drooping at twig tips, female catkins are greenish and upright further back on the same twig. Both are very small and appear in early spring. Birch cones are brown, 1-2” long, and narrowly cylindrical. Cones mature in autumn to release many 2-winged seeds. Birch occupy open forests and moist soils, and in our area can survive most places if irrigated. Birch wood, such as that from Paper Birch, Betula papyrifera, has been used by Native Americans and European settlers alike for pulpwood.
Magnolia are remarkable trees of which there are many species belonging to the genera Magnolia, which belongs to the family Magnoliaceae.
Southern Magnolia, Magnolia grandiflora, is a species native to the south eastern United States which can be found as a landscaping tree in our area, with one located near the Main Beach at LOP. Magnolias can be deciduous or evergreen, and have large (5-8”) ovate leaves which appear shiny and leathery. Their flowers may be their most dramatic feature as they are literally huge compared to the other trees mentioned in this guide. Southern Magnolia flowers have large white petals, with a sweet scent. The flowers may be 12 inches across. The fruit of this tree is a 4 inches long, ovoid shaped, and reddish in color.
The genus of Prunus contains more than 400 species of flowering shrubs and trees and is part of the Rose Family, Rosaceae. The Genus contains the Cherry, Plum, Peach, Nectarine, and Apricot trees along with many other wild species. Collectively these are known commonly as the “Stone Fruits”. The Stone Fruit trees grow from heights of 10-50 feet, and have smooth, red to gray stems when young, which become rough with age. Some species have thorns. Most Prunus species are deciduous, with simple alternately arranged leaves. The leaves have petioles, are ovate, with linear venation and minutely toothed margins. The leaves are often lighter green beneath than above, and depending on species, anywhere from 1 – 4inches in length. The flowers are 5 petaled, with 5 sepals, and as with most Rose types, with many stamens. The flowers can be borne singularly or in clusters along the stems. Flower color is usually white, or some variation of pink to red, and usually no more than 1 inch across. The fruit is technically classified as a drupe, which is a single, hard coated seed enclosed within a fleshy outer protection, which is the delicious fruit that we know and love. The flowers generally bud and open up in the wintertime, before any leaves have developed. There are many varieties of Prunus found, often bred for different characteristics, leaving this to be a fairly variable Genera.
The native Bitter Cherry, Prunus emarginata, which is not found growing wild in Lake of the Pines but is found at higher elevations in the Sierra Nevada has gray stems and white flowers. This wild variety produces a small cherry like fruit, which as its common name implies, is edible but not especially choice.
A common landscaping variety is Prunus cerasifera, commonly called Purple leaf plum. This tree which is native to Europe grows to heights of 30 feet actually has dark burgundy colored leaves, and is used as a landscaping tree for this purpose rather than for its fruits.
Tree of Heaven, Ailanthus altissima, is a non-native deciduous tree found throughout the Gold Country region of the foothills belonging to the mostly tropical family Simaroubaceae. Tree of Heaven is a direct legacy of the very thousands of Chinese who came to this area during the Gold Rush. It was originally brought by Chinese laborers who worked and lived in Northern Mine and railroad camps, and most likely planted by them as a reminder of home. It is a fast growing tree, reaching heights of 50 feet in only 25 years. It has smooth, light gray bark. It has compounded leaves, with 10 or more pairs of pointed ovate-lanceolate leaflets 2 to 7 inches long. The leaves are green and often with reddish hues. The leaves have a distinct, slightly unpleasant (to me) smell when crushed. Tree of Heaven is dioecious, with male trees producing several times more flowers than females. Its inflorescences are panicles of many (50 or more) small white flowers. Upon fertilization female trees produce winged fruits 1 inch in length, which may persist on the tree through the winter. Female trees are prolific seed producers, around 14,000 seeds per pound. Tree of Heaven can be seen growing from roadside ditches as well as dry areas, and it reproduces from new stem growth, or ‘suckers’. In Nevada County as well as other Gold Country areas tree of heaven has become a noxious tree for its tendency to displace native trees and shrubs and invade disturbed sites, such as the abandoned mines and railways where it was first introduced.