This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds.
Time of bloom: May to September.
Seed-time: Late June to October.
Range: Eastern Canada and New England to Michigan and Kansas, southward to Florida and Texas. Habitat: Dry soil; thickets and waste places.
The very large fleshy roots of this plant are edible and sweet, and are buried very deep in the ground below the reach of frost; they are sometimes more than two feet long, and so thick as to attain a weight of over thirty pounds. Several stout, smooth stems spring from the same root, trailing or twining for a length of three to twelve feet. Leaves alternate, deep green, heart-shaped, long pointed, sometimes drawn in at the sides to a fiddle-shape, two to six inches long, with slender petioles often longer than the blades. Flowers like those of the morning glory, the corollas funnel-shaped, two to three inches long, white, with five pinkish purple stripes, often several on one stalk, which lengthens very much as the seed ripens; stamens five, inserted low down on the tube of the corolla and alternating with its lobes; ovary two celled, with entire or two-lobed stigma. Capsules globular, two-celled, containing two to four seeds, which have fine wool all around the margins. (Fig. 223.)
Except to satisfy hunger it would not pay to dig for these deeply buried roots. Repeated deep cutting of the stems, putting a handful of salt or a few spoonfuls of crude carbolic acid on the shorn surfaces, will finally subdue the weed.
 
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