National Park Service Featured Creature U.S. Department of the Interior January 2020 Klamath Network Inventory & Monitoring Division Natural Resource Stewardship & Science White Alnus rhombifolia

General Description Reproduction As early as January, when many are still White can reproduce by or veg- dormant, you might find yourself sneezing etatively from the roots. For reproduction by through a cloud of white alder pollen. Alders seed, both male and female grow on a are members of the birch family (), single white alder , making it monoecious NPS photo and several species of alder grow natively in (meaning “single house”). The new reproduc- North America, typically near streams. tive cycle actually begins in the summer or fall White alder and female . before the next spring’s bloom, when clusters The white alder, Alnus rhombifolia, also called (catkins) of female flowers begin developing pileated woodpeckers or red-breasted nut- the alder, is an inland tree of the as a small roundish green growth. Yellowish hatches sometimes nest in white alders. Cascade and Sierra Nevada mountain ranges, male clusters (catkins) form into long closely related to but not often overlapping (3–10 cm; 1.2–3.9 in) slender, drooping cylin- Alders have a handy adaptation not often its more coastal cousin, the red alder (Alnus ders that don’t release their pollen until early seen outside of the legume family: they can rubra). It sports dark green, glossy leaves with spring (Jan–Apr). Neither flower is showy, “fix” the vital nutrient, nitrogen. Bacteria finely toothed edges that are lighter green since they are wind-pollinated and don’t in their root nodules move nitrogen from the underneath. Its light gray bark is smooth need to attract insects. A large volume of pol- air into the soil, making it available to the tree when new and increasingly scaly with age, len can be released during this time, before and nearby . For this reason, alders can though less scaly and not as dark or reddish the new spring leaves emerge. Over the spring, more readily colonize disturbed, nitrogen- as the red alder’s bark. Typically growing to summer, and fall, the female flowers mature poor landscapes than other trees that lack 15 m (50 ft) tall, it is shorter than its red alder into the small “cones,” or strobiles, so char- this adaptation, and are valuable for restora- cousin, which can reach almost three times acteristic of alders, eventually releasing their tion projects. as high. Its leaves are also flat at the edges, in into the wind or to hungry birds. contrast to the slightly rolled edges of a red Ethnobotany alder. Alders are easily recognized by the Alder tree parts have been used medici- woody female fruiting bodies, called strobiles, nally by Native American tribes, as well as which are up to 2.2 cm (3/4 in) long and look by Chinese and Ayurvedic practitioners. like small, brown, pinecones upon maturity. Conditions treated include cancer, diar- Another curious trait is that most alder leaves rhea, consumption, and many more. Alder don’t change color in the fall before dropping. tree parts were also used as a topical remedy for burns and other skin afflictions. Red Habitat and Distribution alder bark produces a dye used by Native White alders grow along streamsides or just Americans for basketry and clothing. adjacent to them on the dryer, rocky slopes above. Occupying a wide elevational range, Where to See they occur from just above sea level to almost The white alder grows in Whiskeytown NRA,

2400 m (8000 ft), primarily in California, @Charles Schelz Redwood NSP, and Oregon Caves NMP. Oregon, Washington, Idaho, and Montana. Pendulous male catkins; round female strobiles. Learn More Ecology http://www.natureofbend.com/ White alders, like many riparian plants, feed blog/2016/10/14/a-little-autumn-tale-about- and shelter much wildlife. Flocks of pine alders siskins devour their seeds. Mule deer eat their twigs, leaves and buds. Beavers eat their bark https://calscape.org/ and build their dams and lodges with alder Alnus-rhombifolia-(White-Alder) wood. Western Tiger Swallowtail butterflies use them as a host plant. The nitrogen-rich Klamath Network litter that drops from an alder into the Southern Oregon University stream nourishes stream invertebrates, like 1250 Siskiyou Blvd

@Charles Schelz Ashland, OR 97520 caddisfly larvae. And cavity nesters, like White alder in January, S. OR., draped in catkins. PREPARED BY SONYA DAW EXPERIENCE YOUR AMERICA™