Local Trees: The Enchanting Dogwood

Ideally, you'd be reading this in very early spring, when the dogwood bloom is beginning to work its elegant magic in the older neighborhoods fanning out from Lower Bidwell Park and downtown Chico. Their flowers bloom before dogwoods leaf out, so the blooms appear to float, suspended on slender, graceful branches. But now, although their bloom time is over for the year, the new foliage on dogwoods makes them attractive landscape trees, creating filtered shade in gardens and yards across town.

There are between 30 and 100 different species of Cornus (depending upon the source one consults). These various species of dogwood are native throughout much of earth's temperate latitudes and boreal (subarctic) ecosystems of Eurasia and North America. China, Japan, and the southeastern United States are particularly rich in native species. The best known and most widely cultivated dogwood species include: common dogwood (C. sanguinea) of Eurasia; flowering dogwood (C. florida) of eastern North America; Pacific dogwood (C. nuttallii) of western North America: Kousa dogwood (C. kousa) of eastern Asia, and two low-growing boreal species, the Canadian and Eurasian dwarf cornels (or bunchberries), C. canadensis and C. suecica respectively. This article focuses on two species that do particularly well in our area: Pacific dogwood and flowering dogwood.

General Characteristics: Dogwood trees are on the small side, ranging between 15 to 40 or so feet high. Typically, trunks are one foot or less in diameter, and often sport multiple stems. They provide four full seasons of delight: spring flowers, summer leaves, fall color and berries, and once all of those have dropped off in winter, the trunk displays a distinctive patterned bark and a pleasing rounded form with horizontal branching.

What we see as “flower petals” on the dogwood are technically bracts (modified or specialized leaves) surrounding a bunch of very small, tightly clustered umbel shaped flowers. The leaf itself is a simple, untoothed bit of beauty, distinctive for its visible veins curving as they extend to the margins of the leaf. In fall, the leaves change to an attractive reddish-purple or reddish-brown before dropping. Its bright colored berries are actually drupes, a fleshy fruit with thin skin and a central stone containing multiple seeds. These “berries” provide food to many bird species, and are also utilized by some butterflies and moths. Depending on the species, berries range from very tart and mildly toxic to humans, to tasteless, to slightly sweet and somewhat palatable.

Cornus florida: The flowering dogwood is a popular landscape tree throughout the United States, and is commonly seen here in Chico and our surrounding area. The species name florida or florido is Spanish for “full of flowers” or “flowery”. Native to the Eastern US and northern Mexico, flowering dogwood attains its greatest size, up to 40 feet tall, in the Upper South where hot, humid summers contribute to new, lush growth. In other climates, such as ours, heights of 30–33 feet are more typical. This dogwood species' life span tops out at about 80 years. While its berries, ranging from bright red to yellow with a rosy blush, taste awful to humans, they are not toxic, and are an important source of food for many birds.

When in the wild, flowering dogwood can typically be found decorating the understory of forest edges, and can also occur on dry ridges. Most of the wild trees have white bracts, but some range from pink to rosy to an almost true red.

Cornus nuttallii: The species name of the Pacific dogwood honors Thomas Nuttall, an English botanist and zoologist who lived and worked in America from 1808 to 1841. Nuttall travelled widely and published a number of books on North American plants and birds. Almost 100 plant and animal species bear his name.

Nuttall's namesake dogwood species is commonly known as western dogwood, mountain dogwood, and Pacific mountain dogwood, as well as Pacific dogwood. This species is native to a large swath of western North America, sweeping down the continent from southern British Columbia to southern California, with an isolated population cropping up in central Idaho. On a California map, its distribution pattern looks like a large cane. The short, hooked end starts in the coast range north of the San Francisco Bay, thickening as it bends east through the Klamath and Siskiyou mountains, with the straight side of the cane extending south through the western slopes of the Cascades and Sierra Nevada mountains to the southern end of the great Central Valley. A small distribution also occurs in the southwestern corner of the state.

Pacific dogwood thrives under the canopy of California's mountain forests. When in bloom, flowers hover like lace in the shadows of taller conifers and hardwoods, reaching out for sunlight. While the bracts appear white from a distance, they are actually white tinged with a lovely pale green, and the densely packed, tiny flowers they encircle are also greenish-white. The pink-red drupe can contain up to 100 seeds. The fruit provides sustenance in autumn and sometimes early winter, to small mammals and birds such as grosbeaks, cedar waxwings, and woodpeckers.

Besides its timeless aesthetic appeal, the Pacific dogwood has various utilitarian functions. It was an important plant for the Native tribes of the continent's west coast. Medicinally, the bark was used as a laxative, a tonic, an antiseptic, and for relief of stomach pain. Peeled twigs provided natural toothbrushes, and smaller branches were sometimes used in baskets. Today the wood of the Pacific dogwood is often used for fashioning items such as tool handles and cutting boards because of its hard, strong wood and beautiful tight grain. It has also been used to make thread spindles, golf club heads, and piano keys.

Dogwood is a curious name for a tree. But “dogwood” is actually this tree's third-generation common name. In the 14^th century it was called the “whipple-tree” – a whipple being a straight piece of wood linking the drawpole of a horse cart to the harnesses of the horses. By the early 15^th century the name had shifted to “dagwood,” because its slender and very hard wood stems were used to create “dags” (daggers, skewers, and arrows). Over time, the “a” in “dagwood” became pronounced and written as an “o,” giving us “dogwood” as the final common name for all species of Cornus.

I love the ethereal beauty of the dogwood. Since a large number of cultivated dogwood trees grace our area, evidently so do many others. In fact, dogwood was among the top choices for America's National Tree in a nationwide survey hosted by the Arbor Day Foundation, coming in third behind the oak and redwood: a very respectable ranking!

For more information on gardening in our area, visit the Butte County Master Gardener web page at: http://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.

Photo Credits:

Cornus nuttallii in bloom by Stan Shebs: http://commons.wikimedia.org/wiki/User:Stan_Shebs

Cornus nuttallii closeup of flower by Walter Siegmund - The small flowers are in a dense cluster surrounded by large white bracts. Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1724799

Cornus florida closeup of pink flower by Famartin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=28041080

Flowering dogwood bracts by UC ANR

Cornus florida or Eastern dogwood by Brent McGhie

Stellar Pink, a cross between a florida and kousa dogwood by J. Alosi