Arrowweed
WHAT SUNFLOWER-RELATED SHRUB CAN GROW “STRAIGHT AS AN ARROW” IN WETLANDS PARK?
Arrowweed (Pluchea sericea) is a shrub in the sunflower family (Asteraceae) that is widely distributed across the deserts of the southwestern United States and northern Mexico. In the Las Vegas Valley, as well as Clark County Wetlands Park, it occupies riparian zones such as washes, streams, springs, and floodplains. The plant is especially well adapted to the arid climate, tolerating saline soils and relying on underground water sources. Its name derives from its historic use by Indigenous peoples who fashioned its straight stems into arrow shafts for use in hunting.
The evergreen shrub typically reaches seven to 10 feet in height and spreads into broad, dense stands. Arrowweed stands grow from extensive rhizome systems. These underground systems of interconnected stems send up leafy shoots that pack densely, allowing the plant to dominate large patches of habitat. Each arrowweed colony is a clone-a single genetic individual! The leaves are narrow, lanceolate, and covered in fine silvery hairs, giving the plant its distinctive gray-green appearance. During spring and early summer, arrowweed produces thimble-shaped clusters of small pink to purple disk flowers, which lack the showy ray petals that are characteristic of many other members of the sunflower family.
Arrowweed is often associated with perennial water sources, though it can also establish along disturbed washes where seasonal flooding occurs. Arrowweed’s preference for moist, yet saline soils, allows it to persist where many other native shrubs cannot. With the decline of native cottonwood-willow habitats in Nevada, arrowweed has become an increasingly visible component of the remaining desert riparian plant communities.
The shrub plays an important role in stabilizing soils and maintaining habitat structure. Its dense thickets reduce erosion along waterways and provide cover for a variety of wildlife. Birds frequently use its branches for nesting sites, while small mammals shelter in its undergrowth. The seeds and flowers serve as food sources for seed-eating birds and pollinating insects, including bees and butterflies. Arrowweed is a valuable, flexible contributor to the overall biodiversity of southern Nevada’s riparian ecosystems.
Ethnobotanical uses of arrowweed are well documented. Indigenous peoples of the Southwest, including the Southern Paiute and Havasupai, harvested the plant extensively. Its straight stems were selected for crafting arrows, lances, and other tools. One way native peoples ensured the propagation of straight stalks was to regularly cut young stock off close to the ground; the second growth grew as strong, straight shoots from the base in a circular, crown-shaped pattern. Larger bundles of the plant were used for constructing shelters, fences, and roofing. Additionally, the roots were roasted and eaten, and the resinous gum was applied as an adhesive. Medicinal preparations from leaves and stems were used to treat ailments such as diarrhea, sore throats, and eye infections.
Arrowweed’s vigorous rhizomatous growth has both positive and negative ecological implications. While its ability to form large, continuous stands stabilizes riparian soils and supports wildlife, it can also limit plant diversity by shading out smaller herbaceous species. Management strategies typically balance the need to control its spread with recognition of its value as a native soil stabilizer and habitat provider.
Arrowweed’s persistence in Clark County Wetlands Park and the general area highlights its adaptability in the face of environmental pressures. Even if its dense stands require occasional management, its endurance makes it a symbol of resilience within the Park’s fragile ecosystems.
– By Constance Carlson; photos by Wetlands Park Friends archives
Please enjoy these YouTube videos:
Spotlight on Shrubs: Desert Arrowweed (Pluchea sericea) Brian Powell 10:26
The Fascinating Desert Plant with a Survival Secret Trek Las Vegas 0:55