Sunday, July 3, 2011

Swamp azalea

Janet writes:  Lately I have been looking closely at plants of all kinds, and noticing how common "hairs" are on various structures: twigs, buds, leaves, stems, and flowers.  These hairs are quite different from those on the skin of most mammals.  More accurately called trichomes, plant hairs have many functions.  They may deter herbivores, guide the path of pollinators, or affect photosynthesis, leaf temperature, or water loss.  Some trichomes have glands which store and secrete chemicals that interact with herbivores or pollinators.

In the photos you see swamp azalea, Rhododendron viscosum, (found at the edge of a pond in Sudbury, MA), the buds of which are equipped with secretory glands on their tips.   If you click on the photo you should be able to see the tiny, rust colored glands on the tips of the "hairs".  I have not been about to find out exactly what their function is, but I am guessing from the species name "viscosum", that they secrete sticky substance which may help deter herbivores.


  1. I just wrote a couple of blog posts that might be of interest, about insects protecting themselves with sycamore trichomes:

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