Alnus rhombifolia
Alnus rhombifolia, the white alder, is an alder tree native to western North America, from British Columbia and Washington east to western Montana, southeast to the Sierra Nevada, and south through the Peninsular Ranges and Colorado Desert oases in Southern California. It occurs in riparian zone habitats at an altitudes range of . While not reported in northern Baja California, it has been predicted on the basis of its climatic adaptation to occur there also. Alnus rhombifolia is primarily found in the chaparral and woodlands, montane, and temperate forests ecoregions. Description
Alnus rhombifolia is a medium-sized deciduous tree growing to  (rarely to ) tall, with pale gray bark, smooth on young trees, becoming scaly on old trees. The leaves are alternate, rhombic to narrow elliptic,  long and  broad, with a finely serrated margin and a rounded to acute apex; they are thinly hairy below. The flowers are produced in catkins. The male catkins are pendulous, slender,  long, yellowish, and produced in clusters of two to seven; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn  long and   broad, on a   stem, superficially resembling a small conifer cone. The small winged seeds disperse through the winter, leaving the old woody, blackish 'cones' on the tree for up to a year after. The white alder is closely related to the red alder (Alnus rubra), differing in the leaf margins being flat, not curled under. Like other alders, it is able to fix nitrogen, and tolerates infertile soils. Medicinal use
Some Plateau Indian tribes use white alder for female health treatment needs. References

External links

  Jepson Manual treatment-  Alnus rhombifolia
 USDA: Alnus rhombifolia  - data and range maps
 Alnus rhombifolia - Photo gallery

rhombifolia
Trees of Western Canada
Trees of the Northwestern United States
Trees of the Southwestern United States
Plants described in 1842
Plants used in traditional Native American medicine
Garden plants of North America
Ornamental trees