An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
TRAILING FOUR O'CLOCK
FOUR O'CLOCK FAMILY-Nyctaginaceae
TRAILING FOUR O'CLOCK-Allionia incarnata L.
DESCRIPTION-A prostrate perennial from a long thick root, reproducing only by seeds. The stems trail on the ground, but do not root at the joints. They are 1/2 to 3 feet long, and covered with glandular hairs which collect dirt. The leaves, also glandular hairy, are dirty green above, silvery beneath, and 1/2 to 3 inches long, including the stalks. They are oblong or eggshaped, opposite on the stem, and often the pair is of unequal size.
The flowers, in clusters of 3 at the leaf axils, are rose purple and very pretty, 1/2 to 1 inch in diameter. The narrow brown fruit is rodshaped, flattened, and about 1/8 inch long. Down the center of one side there are 2 rows of sticky green glands which are more or less hidden by the 2 overhanging margins. The margins, each with 4 to 6 triangular teeth along its edge, may be quite broad and almost meet in the center, or they may be very narrow, not covering the glands.
DISTRIBUTION-Trailing four o'clock, a native weed, is common throughout most of the state on dry hard soil, along roadsides, sidewalks, paths, and waste places. It is also found on rocky desert mesas and slopes, sandy washes, or river bottoms; 100 to 6,000 feet elevation; flowering February to October, but very conspicuous in late summer.
Copyright (c) 1972 The Arizona Board of Regents