Natural World: Acacia may not cause your sneezes
Despite this winter’s odd weather patterns—little rain, with intensely cold spells followed by unseasonably warm days—Sonoma Valley’s acacias are blooming right on schedule. Right now the spectacular trees can be spotted all over the Valley.
Acacias are hard to miss. Their time on the floral stage begins in January and runs into March—and they make the most of it. At the height of blooming, the spectacular trees are festooned with profusions of soft, puffy, lemon-yellow orbs.
Many people believe that they’re allergic to Acacias because their allergies (hay fever, for example) act up when those yellow blossoms appear. However, Acacias are considered to be only mildly allergenic. Acacia pollen, which is heavy, sticky and large, is not easily spread by wind (Acacias rely on insects for pollination).
Other, less visibly-blooming, culprits are usually responsible for someone developing an allergic response at this time of the year. For instance, oaks, cypresses, and pines shed lightweight airborne pollen at the same time as Acacia. Since these trees don’t need to attract insects for pollination, their blooms haven’t evolved to be noticed.
Dr. Ed Newbigin, a Botanist at the University of Melbourne who is an expert in Acacia pollen, has stated that “most of those people whose hay fever comes on in late winter/early spring associate this with acacias because they are so obviously flowering at this time.
“However, they ignore the deciduous trees…that are also flowering and producing copious amounts of pollen that is known to be highly allergenic. Being wind-pollinated, the flowers of those trees tend to be quite small and are not showy.”
A few interesting facts about Acacia:
- The world is home to about 800 species of trees and shrubs in the Acacia genus.
- Acacia is native to various tropical and subtropical regions, but particularly Australia and various Pacific Ocean islands.
- Acacia leaves have a feather- or fern-like appearance that comes from the fact that they are small, finely divided leaflets.
- The bark of most acacias is tannin-rich. Tannin is used to tan leather and in dyes, inks, pharmaceuticals and other products.