Introduced. Annual. Propagates by seeds. Time of bloom: July to September. Seed-time: Earliest flowers mature as early as September, later ones clinging to the plant until nearly springtime. Range: Ontario and Manitoba to Idaho; nearly throughout the
Mississippi Valley; in Kansas, Nebraska, and Colorado; locally in Eastern States. Habitat: Dry soil; invades most crops; waste places.
A most pernicious weed, which was brought to this country in impure flax seed from Russia not many years ago, but its range is already large and is steadily increasing. Because of its excessive prickliness, the Dakota farmers who first made its acquaintance called it Thistle and Cactus; but it is neither, being a Saltwort and a member of the Goosefoot Family.
The seedlings are innocent-looking, grass-like shoots, divided into two blades, appearing in April, May, and June. The young stalks are tender and succulent, the young leaves an inch or two long with young branchlets in their axils; at this stage of growth the plant is good forage which cattle and sheep eat greedily. But with the approach of summer weather the plants change their character: the stem becomes hard and woody, two to three feet high, ridged, and streaked with red lines, diffusely branched and spreading broadly, crowding to death all lesser growth. The first leaves fall away; those of later growth are not more than a half-inch long, mere awl-like spines slightly broadened at base and having on each side a sharp pointed bract which is somewhat shorter. (Fig. 72.) Flowers axillary, sessile, and usually solitary, very small, greenish white or often pink; calyx five-parted, with five stamens and two styles; when mature the calyx-lobes are horizontally winged on the back, forming a papery margin which often helps the seed to be carried before the wind, independent of the tumbling of the parent plant. Seed very small, reddish in color, irregular in shape but somewhat like a flattened top, held in place by fine tufts of coiled hair at the base of the persistent calyx, so that only the ripest will fall when the plant is broken from its hold on the soil and sent tumbling before the wind; but they continue to ripen and shake loose all winter as the weeds are trundled about. According to the size attained, a thrifty plant may bear ten thousand to a hundred thousand seeds, which retain their vitality in the soil for several seasons.
Fig. 72.-Russian Thistle (Salsola Kali, var. tenufolia). X 1/4.
Sow clean seed. Prevent the production of seed. When the weed is cut close to the ground before seeding, it dies. Young seedlings, six or eight inches high, may be plowed under, a drag-chain being used to help pull them beneath the turning furrow. On such land, plowed as late as July, a soiling crop of corn or rape may be grown. In such cultivated crops as potatoes, corn, and beets, tillage should be continued later than is customary. In grain fields, particularly those harvested with a header, the stubbles should be burned over, first being mowed and dried for a few days if the weeds are still green. Entire communities should be concerned in keeping highways, firebreaks, and all waste land clean of the pest.