Species In Our
"Rhodora," or Rhododendron canadense to give it its proper name, is a modest little deciduous plant - rarely over three feet tall - that hides in bogs and other cold wet areas anywhere it can find them, from Labrador (-35°F) to New Jersey (+100#176F). It is easy to identify. As Peter and Ken Cox say, "This very distinct species is unlikely to be confused with any other azalea, having a low, upright, stoloniferous habit, and a rosy-purple or white corolla, two-lipped with the lower lip divided, more or less lacking a tube" (Encyclopedia of Rhododendron Species, Glendoick Publishing, 1997).
This description is perfectly adequate to identify Rhodora. There is no need to take a magnifying glass to its one-to-two inch, slightly hairy bluish-green leaves, or to count the three joined upper lobes and two distinct lower lobes of its flowers, or to examine other minute details of its anatomy.
In the autumn, one can easily tell the rarer white flowered form by its yellowish leaves from the rosy-purple form which has bluish-purple autumn color.
The bog behind my house has numerous humps or tussocks that are slightly above the water level where Rhodora grows in abundance. In spring, the bog suddenly glows in a haze of rosy-purple as the big drifts of Rhodora come into bloom before their leaves appear. Within a week the color disappears and the Rhodora plants again hide among the Leatherleaf and other bog plants until the next spring. Peter Cox once tried to get some seed from these plants, but the depth of the bog thwarted his attempt. I guess Rhodora just "wants to be left alone!"
Unlike most other Rhododendrons, Rhodora strongly resists hybridizing, even with R. vaseyi, the only other species that has been placed with it in Subgenus Pentanthera Section Rhodora.
It has been grown by several of our chapter members (including me) in their gardens. The consensus is that it needs just the right amount of moisture - never dry, but never soggy. Most of us have lost more than a few to just those conditions, but when it picks its own home, it thrives!
Bill Sweeney, Concord, MA