Plant of the Week
Rocky Mountain Bee Plant (Cleome serrulata)
By Teresa Prendusi
One of the showiest wildflowers in the western and prairie regions of the United States is the beautiful pink-flowered Rocky Mountain Bee plant. Often found along dry roadsides and waste places, this annual herb that can grow up to 4-feet tall. It has an unpleasant odor and is mostly avoided by livestock. The stem leaves are divided into three linear-eliptic leaflets that are arranged alternately along the stem. The nectar-filled blossoms are clustered in elongated racemes near the top portion of the stems and attract a diverse array of pollinators, including bees, butterflies, and wasps. Each flower has four petals and sepals and six long showy stamens. This species has a long blooming season: anytime from May thru September, depending on location and elevation. The fruits are distinctive podlike capsules, up to four inches long, and droop downward from elongated stalks.
Rocky Mountain Bee Plant can be found throughout western North America, from southern British Columbia, east to Minnesota, and as far south as Arizona and New Mexico. It is now also naturalized in eastern areas of North America. This species was one of the many new plants collected in 1804 during the Lewis and Clark expedition.
Cleome serrulata is an important cultural plant for many Southwestern Indian tribes. The young, tender shoots and leaves are good sources of vitamin A and calcium. In the past they were used as potherbs or medicinally as teas for fevers and other ailments. The seeds were ground and used to make gruel or bread. The Navajo still use the plant as a source of yellow-green dye for their beautiful wool rugs and blankets. Many pueblo tribes use a concentrated form of dye, made from boiling the plant into a thick black resin, to paint designs on pottery or for decorating their baskets.
Cleome serrulata has traditionally been considered a member of the Caper (Capparidaceae) family but recent genetic studies indicate that it is much more closely related to the Mustard (Brassicaceae) family. Many current floras have adopted a new scientific classification in recognizing the family, Cleomaceae.