This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Ellisia Nyctelea, L. (Macrocalyx Nyctelea, Kuntze.)
Native. Annual. Propagates by seeds. Time of bloom: April to June. Seed-time: May to July.
Range: New Jersey to Minnesota and the Saskatchewan, southward to Virginia, Missouri, Nebraska, and Colorado. Habitat: Grain fields, meadows, waste places.
Although this plant ranges nearly across the Continent, it is most troublesome as a weed in the wheat-growing country of the Northwest, where it appears early in spring, makes a rapid growth which absorbs much of the food and moisture needed by the crop, matures its fruit, and dies down early in July.
Fig. 228.-Skunk-weed (Navarretia squarrosa). X 1/4.
Stem four inches to a foot high, slender, and diffusely branched. Leaves two to four inches long, with slender petioles, the upper ones alternate, the lower ones usually opposite; all are pinnately divided, but the segments of the upper ones are usually entire, those of the lower ones toothed or lobed. The whole plant is finely rough-hairy and has a rank, disagreeable odor. Flowers solitary on slender peduncles, from the forks or opposite the leaves; occasionally the later ones are in one-sided clusters of two or three. They have a calyx of five-pointed lobes and a five-lobed, nearly cylindrical, white or bluish corolla, with five included stamens and two styles, united at the base. Calyx and corolla of about the same length (a little more than a quarter-inch) when the flower first opens; but as the fruit forms the calyx enlarges and spreads widely, becoming a five-pointed star-shape, nearly an inch broad, with a small globose two-celled capsule in the center usually containing four seeds. (Fig. 229.)
In grain fields the seedlings should be dragged out with a weeding harrow in the spring, when the crop is but a few inches high. Short rotations with cultivated crops will most easily keep the weed in subjection.