This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds.
Time of bloom: May to June.
Seed-time: June to July.
Range: Pennsylvania to Minnesota and Nebraska, southward to
Georgia and Arkansas. Habitat: Upland fields, meadows, and pastures, open woods, and waste places.
The range of the Dwarf Larkspur includes much grazing land, and the losses caused by it yearly are very considerable. It is said to be the most dangerous in early spring, when the young green leaves are but a few inches above the ground. Full-grown plants not only contain less of the poisonous properties, but are less attractive as forage, and it is stated that deaths from Larkspur poisoning nearly always occur before the plants are in bloom.
Stem rather stout, simple, nearly smooth, succulent, six to fifteen inches tall, springing from tuberous and clustered roots. Leaves palmate, on long petioles, each of the five lobes again deeply but unequally three- to five-cleft. Panicles loose and open, bearing usually not more than six or eight bright blue flowers about an inch in length; the upper sepal, or spur, is nearly straight and ascending; petals four, the two upper ones yellowish with blue lines, the lower two bearded inside with white hairs. Follicles three or four, widely divergent, each about an inch long, tipped with a short beak. The seeds are smooth. As soon as they mature the foliage dies down and the plant seems to be dead. (Fig. 112.)
The perennial roots must be killed and that is most quickly and certainly accomplished by removing them from the soil. The clustering tubers do not lie very deeply beneath the surface and may be readily grubbed out, or even pulled by hand, when the ground is soft. Hand-labor is expensive, but the price of a valuable cow would pay the wages of an ordinary farm laborer for a considerable time. Land too rankly infested to be so cleansed should be put under thorough cultivation and then heavily reseeded.