This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Perennial. Propagates by seeds. Time of bloom: May to July. Seed-time: July to October.
Fig. 107. - Creeping Buttercup (Ranunculus repens). X1/3.
Range: Throughout the United States and southern Canada, but most' abundant in the eastern part. Habitat: Meadows, pastures, roadsides, and waste places.
The range of this weed has of late years greatly increased, mostly by the agency of baled hay. It is one of the most acrid of its tribe, the juices causing blisters when applied to the skin, and cattle cannot eat it in the green state; but drying seems to deprive it of this dangerous quality, and therefore less strenuous endeavor is made for its extermination than is deserved by so noxious a weed.
The bulbous base of this plant is well fringed with long, fibrous, feeding roots. Several stems usually grow from the same root-tuft, six to eighteen inches high, erect, slender, more or less branched, grooved and hairy. Lower leaves long-petioled, three-parted, with the segments again usually three-cleft, sharply toothed, the terminal segment having a somewhat lengthened stalk. Stem-leaves much smaller, less divided and sessile. Flowers bright yellow, so lustrous that they reflect light, about an inch broad, the petals much longer than the hairy, reflexed sepals; the blossoms are often partly double, the peduncles slender and grooved. Head globose, containing many small flattened, short-beaked carpels, so nearly of the size and weight of grass seeds that they are very difficult of separation. (Fig. 108.)
Hand-digging will pay if the infestation is new and the plants not so numerous as to make the task impracticable; but it is worth considerable trouble to save a plot from being fouled by the seeds. Ground too rankly infested to be so cleansed should be broken up, put to cultivated crops, and be given thorough tillage for one or two seasons.
Fig. 108. - Bulbous Buttercup (Ranunculus bulbosus). X1/4.