R. crenulatum
First Time Blooms!
Steve Hootman
After several years of patiently waiting, our oldest and largest specimen of the enigmatic Rhododendron crenulatum, a very rare member of Subsection Maddenia, has finally flowered. While we were all a bit underwhelmed by the slightly less than one-inch-long cream flowers with golden spots, we were very excited to finally see the result of what we had been hovering over all of these years. The specimen in question has, after seven years, attained the height of eight inches – obviously, a very dwarf and slow-growing alpine species. What makes this species so intriguing, however, is where it is actually found growing as an alpine. It has been found (so far) only on the top of the highest mountain in Laos and on the very top of the highest mountain in Vietnam. In addition, it is the only species of Rhododendron known to have toothed (crenulate) leaf margins. All other species are entire – definitely a non-conformist.
The flower buds, plant habit, and native range are strikingly similar to a recently named species in Subsection Maddenia (R. wumingense) that I was fortunate to observe in the wild in southern Guangxi during my last expedition in November of 2010. I would imagine that there is a close relationship between these two little-known species, but we will need much more information before we can fully understand what has become yet another intriguing mystery in the genus Rhododendron.