This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual and winter annual. Propagates by seeds.
Time of bloom: June to September.
Seed-time: July to October.
Range: Maine to Michigan, southward to New Jersey and Missouri.
Habitat: Grain and clover fields, waste places.
This weed came from western Europe but a few years ago, in red clover seed, from which it is very hard to remove. Wherever established, it has shown itself to be about as prolific and adaptive as Field Pepper grass, and therefore newly entered plants should meet with prompt and severe treatment. (Fig. 119.)
Stem one to two feet tall, slender, with numerous slim branches near the top, gray-green with fine, forking hairs. Basal leaves three or four inches long, spatulate, usually grouped in a small rosette; stem-leaves alternate, lance-shaped, sessile; all have entire edges. Flowers in crowded terminal racemes, and, like all the Cruciferae, have six stamens, four long and two short; four sepals, four petals, arranged in cross-form and situated below the ovary; in this species they are white, minute, the petals cleft at the tip. Pods elliptic and but little compressed silicles, gray-hairy like the rest of the plant, about a quarter-inch long, divided into two cells by a transparent papery partition, which remains on the thread-like pedicel after the seeds have fallen - like an eyeglass in a rim. Each cell contains about a half-dozen flattened brown seeds.
Fig. 119. - Gray Ber teroa (Berteroa incana) X1/3.
Sow clean seed. Plants newly established in clover field or meadow should be hand-pulled or cut by themselves and burned, for their seeds not only will foul the ground, but also, if cured with the hay, will be made certain of further distribution. Their hairy surface makes these weeds susceptible to injury from sprays such as Iron or Copper Sulfate applied when buds are developing. Early spring and late autumn cultivation will destroy the seedlings and rosettes.