(Ipomoea hederifolia or coccinea)
Scarlet Creeper is a long, twining vine which appears rather suddenly in our washes after good summer rains. The ones photographed here were seen September 9, 2004, after several moderate floodings of the Hot Springs Canyon Wash. Young vines of both these plants and Morning Glories were growing up in many locations along the wash.
Below you can see the typically 3-lobed leaves (though some are heart-shaped and some 5-lobed), and on the right the flower at its fullest, a long narrow, flaring tube (up to an inch), with white-tipped stamens (not visible here). Note also the twining pattern of the vine. (Click on each image to enlarge it.) As you might expect, Scarlet Creeper is a strong attractor of hummingbirds.
Here is another image showing the vine architecture, and some leaves that are not so fully lobed: