Excerpts from Jim Conrad's
Naturalist Newsletter

morning glory, IPOMOEA CRINICALYX

from the April 4,  2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
FIGHTING NECTAR ROBBERY A DIFFERENT WAY

Above you see another morning glory species twining in the thicket next to my compost heap. If you look at the corolla's base you'll see that this species uses an entirely different kind of defense against nectar robbers. Its entire calyx is densely covered with long, spiky "tubercles." A close-up of some calyxes is below:

tubercles on calyx of morning glory, IPOMOEA CRINICALYX

Ron Kushner, a morning glory fancier, assures me that this is IPOMOEA CRINICALYX, a species fairly common in thickets here. It's an unusual species in that its leaves are small, blades on my vine not surpassing 1-¾ inches (4.5 cm).