Ivyleaf Morning-glory (Ipomoea hederacea) blooms in the canyons, washes, and riparian areas here in southern Arizona in the late summer and early fall.
Ivyleaf Morning-glory flowers are only open in the morning, and they can be blue, purple, magenta, or white in color. Most of the Ivyleaf Morning-glory flowers here in Tucson are a beautiful sky blue color with a yellowish white throat. The flowers are surrounded by five hairy sepals.
Ivyleaf Morning-glory leaves are usually three-lobed, but they are quite variable and can also be five-lobed or heart-shaped, even on the same plant. The leaves and stems of Ivyleaf Morning-glories are covered in velvety hairs, which distinguishes them from the similar Canyon Morning-glory (Ipomoea barbatisepala), which has hairless leaves and stems.
For some reason, all Ipomoea species here in Arizona, both native and non-native, have been declared prohibited noxious weeds. Ivyleaf Morning-glory is one Ipomoea species definitely deserving of this classification because this weed is not native to Arizona and it is very invasive. In the habitat that it shares with our native Canyon Morning-glory, rampant Ivyleaf Morning-glory unfortunately appears to be crowding it out. For such a nasty weed though, Ivyleaf Morning-glory is quite beautiful, but I'd really much rather see our native Morning-glories in its place.
Note: Some Convolvulaceae experts believe that Ivyleaf Morning-glory is actually native to this part of Arizona.