This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Annual. Propagates by seeds.
Time of bloom: May to August.
Seed-time: June to September.
Range: Ontario to British Columbia, southward to Florida and Mexico. Habitat: Sterile open ground; thin meadows, upland pastures.
Grazing cattle do not like the taste of this plant, and it is usually left to reproduce itself, even where good forage is scarce - as it is likely to be on ground preferred by the weed.
Stem six to eighteen inches long, slender, weak and usually prostrate, with rough-hairy angles or sometimes smooth, simple or branching near the base, very leafy. Leaves alternate, rounded or broadly ovate, clasping the stem by a heart-shaped base, the edges rather finely toothed. Flowers sessile in the axils, solitary or sometimes in twos or threes; the lower and earlier ones are rudimentary, without corolla, and these never open but are self-fertilized in the bud, producing much seed which is often ripened and sown before the upper flowers expand their five-lobed, violet-blue corollas, which are also fertile; stamens five with thin, flattened filaments, shorter than the anthers; style with three-lobed stigma. Capsule oblong or narrowly top-shaped, three-celled, splitting below the middle. Seed brown, lens-shaped, often an impurity of clover and grass seed. (Fig. 285.)
Enrich the ground by liming, manuring, and furnishing it with humus, which will enable it to retain moisture and support the growth of better plants. Hand-pulling of small and newly infested areas is a paying operation but the work must be done before the development of the inconspicuous early flowers.
Fig. 285. - Venus's Looking-glass (Specularia perfoliata) . X 1/4.