An Excerpt from Jim Conrad's
Naturalist Newsletter

Cape Leadwort, PLUMBAGO AURICULATA

from the August 22, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
CAPE LEADWORT

At Hacienda Chichen's pretty entrance a reflecting pool is bordered by knee-high masses of a compact, weak-stemmed herb with bluish-white flowers, as shown above.

With those slender-tubed flowers each bearing five flaring corolla lobes, the average Northerner with a little garden-flower savvy would almost swear that it's some kind of phlox -- until noting what's shown below:

Cape Leadwort, PLUMBAGO AURICULATA, flowers

Cape Leadwort, PLUMBAGO AURICULATA, glands on calyx The slender, green calyxes below the bluish-white corollas are mantled with blunt, hairlike things. A close-up of those club-shaped "hairs" is shown at the right. Those are glandular hairs. If you touch the calyx with a finger you can feel its stickiness, and easily imagine what the hairs are for. If you're an insect looking for food and you're climbing the calyx, you'll get stuck among those hairs before you reach the flower's succulent sexual parts.

There's a genus of popular garden flowers recognized by the very fact that they look like phlox until you notice their glandular hairs. They're known as leadworts orplumbagos. The one at the Hacienda's entrance is the Cape Leadwort, PLUMBAGO AURICULATA, a native of South Africa but now planted worldwide in the tropics and subtropics, where it serves as a low hedge or ground cover. In the US sometimes it's grown in pots that must be taken inside during the winter.

"Leadwort" is something of a klutzy name for such a pretty plant. The name is based on the genus name Plumbago, bestowed by Linnaeus himself, which in Latin means lead. It's not clear what leadworts have to do with lead but I've read one theory that the plants were once used medicinally against lead poisoning.

Last November we reported on a weedy leadwort growing wild here at woods edges. That was Plumbago scandens, and you can compare it with its pretty African cousin at http://www.backyardnature.net/yucatan/leadwort.htm.