An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
SHEPHERDSPURSE-Capsella bursa-pastoris (L) Medic.
DESCRIPTION-An erect annual or winter annual, 1/4 to 1 1/2 feet high, which has a thin taproot, and reproduces only by seeds. The slender stems, usually branching, are sparingly covered by long gray hairs. A spreading rosette of leaves is formed first on the ground. These leaves are variously toothed, cut or deeply lobed, often with a larger lobe at the tip, and 1 1/2 to 5 inches long including the stalk. The stem leaves are alternate, often arrowshaped, with smooth or toothed edges. These leaves are without stalks, and clasp the stem with an earlike lobe on either side.
The small white flowers, with petals only 1/12 to 1/8 inch long, are on slender stalks which elongate as the pods mature. They occur along the upper leafless part of the stems, but the pods often are found almost throughout the length of the stem.
The flat seedpods are inverted, heartshaped, or triangular, with the broad notched end on top, and narrowed to a point at the base, about 1/4 inch broad. The tiny reddish or orange brown seeds are oblong, shiny, about 1/25 inch long, with a groove down each face.
DISTRIBUTION-A European introduction, shepherdspurse is common throughout the state. It is primarily a lawn pest, but is also very common in cultivated crops, orchards, pastures, and roadsides or waste places near them; 100 to 8,000 feet elevation; flowering practically the year around in moist cultivated fields in the low valleys or at the higher elevations, but usually disappearing in May in dry, low elevation areas.
Copyright (c) 1972 The Arizona Board of Regents