Monday, November 13, 2006

Euphorbia Transformation

Everyone is familiar with Euphorbia pulcherrima, the ubiquitous Christmas Poinsettia. They are native to Mexico and Central America. Their winter bloom is induced by the shortening day length. At a critical point, when daylight is less than of 11.5 hours the blooming process begins. If this process is interrupted by close artificial light, such as porch lights or street lamps, Poinsettias will not bloom.

There is another Euphorbia native to southern Mexico down to El Salvador, Euphorbia leucocephala. It is also induced to bloom by the shortening day. It can get quite large almost tree like in size, but is treated more as a shrub. The leaves are small 2 to 3 inches long narrow and linear. For most of the year it is a boring plain green shrub.

Then it blooms. The same process as the Christmas Poinsettia, with leaf bracts changing color and looking flower like below the much smaller true flowers. The difference is the Euphorbia leucocephala does this in miniature and in white. This is then topped off with a medium strength jasmine scent.

The entire shrub turns white and looks like a fluffy cloud. At night its sweet aroma fills the air. This is for me in the tropics a sign of the changing seasons. Yes Virginia there is a winter in Hawaii.

When I arrived here and first discovered this shrub I was told it was called Philippine Poinsettia and that is what I called it. At some point I needed to know its botanical name and looked it up and found out where it was from. Calling it the Philippine Poinsettia didn't seem right any more and I have tried calling it the Mexican Poinsettia, but that doesn't sit well with me either. Filipinos are some of the most avid home gardeners of all the various cultures who have made Hawaii home. I imagine it got its name from them because they were the ones who had been growing it here on Maui. In Hortus Third it is called Pascuita, a Spanish word I would have to look up to translate. I have decided to stick with Philippine Poinsettia in honor of my fellow gardeners on Maui.


Annie in Austin said...

After seeing your photo of the Philippine Pointsettia I googled it - some sites say 35º to 40º F is the limit. I've kept a potted Christmas-gift pointsettia growing since 2002, bringing it in when we dip below freezing. The plant isn't lush and the bracts are small but it sets blooms each fall.
There is no 'medium strength jasmine scent', however! I wonder if any plant growers have produced a small version of Philippine pointsettia in a container? White flowers with a great scent could be a better Christmas plant than the red ones. But you might not like your special plant turned into a mass-market decoration!!


Christopher C. in Hawaii said...

If I had the patent on a mass marketed Philippine Poinsettia I could live with it as a common holiday decoration. It does however shed its bloom by New Years generally, a good sign that the Holidays are over, after turning a pink blush and then the shrub remains naked and bare for another two months before leafing out again.

This year it was about three weeks late in blooming. Wonder what that means. Could the tilt of the earths axis be on an odd wobble?