Like the other weeds, highest pollen levels are in late summer and fall.Ĭlover, alfalfa, and broom are leguminous plants that cross-react allergenically, causing allergy symptoms when their pollen levels peak in the spring and summer. Pollinates in late summer through fall.Ī member of the ragweed family, cocklebur is a coarse weed found in pastures, irrigation ditches, and marshy areas. It turns a brilliant red in the fall and has been used as an ornamental hedge.

This multi-branched compact weed that grows to about three feet high has aliases including Mexican fireweed and fireball. Largest amount of pollen dispersed in May. Abundant birch pollen in the Reno area is responsible for “nose woes” and other allergy symptoms from March through May.Ī close relative of the maples, this fast-growing tree common in the Midwest is sometimes used as a landscaping ornamental in this area. Often graceful, birches pollinate in springtime. Closely related to cottonwoods and poplars, it is an early springtime pollinator. Known for their brilliant yellow color in the fall at higher altitudes and their trembling leaves, the quaking aspen has drooping catkins up to 4 inches long. By the way, the popular mountain ash tree is not related–it belongs to the rose family and is not an allergenic plant. Their flowers appear before their leaves, and we find their pollen in March, April and May. Members of the olive family, ash trees are not native to this area, but are used in landscaping. It is found on dry mountain slopes and canyon walls but can also do well when planted as a drought-tolerant ornamental and is used for windbreaks and erosion control. Wild alfalfa, common along roadsides, pollinates in mid-summer.Ī medium-size tree, the only cypress native to the Southwest. Since it is perennial crop, there is no specific season of pollination. We see many people with positive allergy skin tests to alfalfa, particularly those living in farm and ranch areas. They produce pollen in March through May, before their leaves appear.Ī member of the legume family grown for horse and cattle fodder. Small cones, less than an inch long, emit winged seeds. Plants of Allergenic Importance in Northern Nevada Alder (Alnus species)įound in moist areas such as along streams and on lakeshores, alders in this area are slender trees with drooping pollen-bearing catkins about 3 inches long. Sagebrush, which is Nevada’s state flower and which lends its scientific name-Artemisia-to the University of Nevada’s Yearbook, is responsible for many people’s hay fever and asthma symptoms, especially in the summer and fall. Allergenic pollen is in the air throughout most of the year in northern Nevada, starting in February and persisting into November.

Desert broom plant allergies