California’s Diverse Rose Family


The rose family, Rosaceae, is one of California’s most diverse group of plants. Found throughout the world with thousands of members, the rose family also fills California with over three hundred respresentatives. Although we are all used to to the multi-colored hybrid roses that fill our neighborhoods, most members of the rose family bear little resemblance to these fancy cultivars. Of course, we have our native roses with their simple carnation pink flowers and thorny branches, but the rest of the family is quite varied. Our wild cherries, for instance, are members of the rose family, as are our strawberries and the ubiquitous local native, toyon. If you have ever admired a Channel Island ironwood, Lyonothamnus floribundus, or tasted a wild blackberry of the Rubus genus, then you have enjoyed a plant of the rose family.

Diversity also characterizes the plant communities populated by members of the rose family. You are as likely to find one thriving in constant moisture (such as the large leaved avens or spiraea) as you are to find one in the baking heat of chaparral (such as chamise or mountain mahogany). Our local woodlands are graced by the dwarf rose, Rosa gymnocarpa, while apache plume, Fallugia paradoxa, endures the harsh eastern Mojave Desert. Quite a diverse group, indeed!

With all this diversity, the rose family has something to offer most every garden. Here are a few unusual possibilities for your fall planting:

Chamaebatiaria millefolium, fern bush: This member of the rose family grows throughout much of the Western US. It ranges into California on the eastern side of the Sierra Nevada and Cascades. It grows in rocky settings as an upright shrub to about seven feet. The aromatic leaves are lance-shaped, with numerous fine leaflets. Their overall appearance is somewhat fern-like, which explains the common name. The spring growth terminates in racemes of bright white flowers. Fern bush grows in harsh settings at high elevations. It is reported to adapt quite well to other growing conditions, and does not appear to require a cold winter rest as do many other montane species. It is adaptable to a variety of soil types. After fern bush is established it is a good candidate for a naturalized bed, that is, a bed without supplemental irrigation.

Cercocarpus traskiae - Santa Catalina Island Mountain Mahogany

Cercocarpus traskiae, Santa Catalina Island mountain mahogany: This mountain mahogany grows naturally in a single arroyo on Santa Catalina Island off the California coast at Los Angeles. It has been rare since its discovery in the late nineteenth century, and only became more so with the introduction of goats, pigs and other animals to the island. Fortunately, the plant is grown commercially while earnest effort is applied to preserving wild populations. Like other native mountain mahoganies, Santa Catalina Island mountain mahogany grows in a round to columnar form as a multi-trunk large shrub or tree. The leathery oval leaves are birch-like in appearance. The undersides have a felty covering of hairs, which is this species’ distinguishing feature. The bark is a gray mahogany. The small yellow spring flowers yield numerous clusters of seeds with long, wispy “tails.” This is a hardy and adaptable shrub, well-suited to a Channel Island themed garden in the SF Bay Area.

Amelanchier utahensis - Western Serviceberry

Amelanchier utahensis, western serviceberry, is a common member of montane plant communities throughout California and beyond. In the SF Bay Area this rose relative may be discovered at Mt Diablo or Henry Coe State Park, among many other locations. I was lucky enough to notice a small stand of western serviceberry blooming in May along the east fork of Coyote Creek in Henry Coe. The clusters of white flowers stood out among the darker foliage of the serviceberry and its neighbors. This deciduous shrub grows with a rounded upright form, with dark green leaves and gray bark. The white flowers produce edible blue berries, which are relished by birds. All in all, western serviceberry is a great local shrub for wildlife support.

Fallugia paradoxa - Apache plume

Fallugia paradoxa, Apache plume, is native to the Southwest and northern Mexico. In California it is found primarily in the eastern portion of San Bernardino County. Although a desert native, apache plume does quite well in a variety of settings as long as it is given soil of adequate drainage and mostly sun. Apache plume grows in a vase or open form with small finely dissected leaves and peeling gray bark. Bright white flowers appear in early spring, reminders that Fallugia paradoxa is in the Rose family. These make way for seed pods, each with numerous long feathery extensions attached to the developing seeds. The “plumes” are faintly red in color and can cover the plant for many weeks. Apache plume does well in the coastal environment of Santa Clara County (Sunset zones 15, 16 and 17).

Adenostoma sparsifolium - Red shanks

Adenostoma sparsifolium, red shank, grows from San Luis Obispo County south into Mexico. It grows into an open tree with shredding strips (“shanks”) on red and gray bark and feathery fronds of small leaves. The flower color is cream white as with the closely related chamise, Adenostoma fasciculatum. With careful pruning, redshanks makes an interesting small tree. It is highly adaptable to a variety of soils and is best given little water after it is established.