An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
CLIMBING MILKWEED-Funastrum cynanchoides (Decne.) Schlecht., F. heterophyllum (Engelm.) Standl.
DESCRIPTION-Perennials with milky juice and long twining stems 8 to 40 feet long, which reproduce by seeds and horizontal roots. The leaves are in pairs, thinly covered by short hairs to hairless. The various plants show remarkable variability in the size and shape of the mature leaves. They all have slender stalks, which vary in length from 1/16 inch to over 2 inches. The leaf blades are very narrow-1/16 inch-to very broad-1 3/4 inches. The leaf base may be narrowed to a point and taper into the stalk, or they may be rounded, or 2-angled, or heartshaped, or arrowshaped, or 2-lobed with the lobes pointing outward. They may be narrowed to a long slender point at the tip, or short pointed, or rounde with a point tip. They are 1/2 to 2 1/2 inches long.
The flowers are in characteristic umbrellalike clusters, with 15 to 25 on a slender stalk arising at the leaf axil. They are fragrant, white, whitish yellow, or purple. The brown seedpods are l 1/2 to 3 1/2 inches long, 1/3 to 2/3 inch wide. The reddish brown seeds are 1/8 to 1/4 inch long, slightly toothed at the rounded end, with a tuft of soft silky hairs at the narrow end.
DISTRIBUTION-Climbing milkweed is a native weed growing in dry sandy soil, and a nuisance around ranches, often climbing on fences, ditches, small trees and shrubs, and spreading into gardens and cultivated fields. Also common in desert washes and arroyos throughout southern and central Arizona; 100 to 5,500 feet elevation; flowering April to October; the seedpods persisting until November.
Copyright (c) 1972 The Arizona Board of Regents