Ragweed allergies
Among plants growing along the roadside are goldenrod
(Solidago spp.) and ragweed (Ambrosia spp.) . Many people
associate their allergy problems that they experience this time of year
with the flowering of goldenrod. This is a misconception based on the fact
that goldenrod inhabits the same habitat as ragweed and that it flowers
at the same time as ragweed. Further, ragweed produces green, non-showy
flowers which are relatively inconspicuous, while goldenrod flowers are
showy and the plants are very noticeable. Ragweed is wind pollinated (hence,
the green, non-showy flowers) while goldenrod is insect pollinated (bees,
etc.). Why is ragweed more likely to cause allergy problems than
goldenrod? One possible answer is simply the fact that ragweed is wind
pollinated. Because pollination is not directed, wind pollinated species
must produce vast quantities of pollen to ensure that successful fertilization
occurs. Animal pollinated species, on the other hand, produce much less
pollen and are rarely important as allergens.
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