This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flowers-heads - Showy, bright golden yellow, the 6 to 10 wedge-shaped, coarsely toothed ray florets around yellowish disk florets soon turning brown; each head on a very long, smooth, slender footstalk. Stems: 1 to 2 ft. high, tufted. Leaves: A few seated on stem, lance-shaped to narrowly oblong; or lower ones crowded, spatulate, on slender petioles.
Preferred Habitat - Open, sunny places, moist or dry.
Flowering Season - May - September.
Distribution - Western Ontario to Missouri and the Gulf States; escaped from gardens in the East.
Glorious masses of this prolific bloomer persistently outshine all rivals in the garden beds throughout the summer. Cut as many slender-stalked flowers and buds as you will for vases indoors, cut them by armfuls, and two more soon appear for every one taken. From seeds scattered by the wind over a dry, sandy field adjoining a Long Island garden one autumn, myriads of these flowers swarmed like yellow butterflies the next season. Very slight encouragement induces this coreopsis to run wild in the East. Grandiflora, with pinnately parted narrow leaves and similar flowers, a Southwestern species, is frequently a runaway. Bees and flies, attracted by the showy neutral rays which are borne solely for advertising purposes, unwittingly cross-fertilize the heads as they crawl over the tiny, tubular, perfect florets massed together in the central disk; for some of these florets having the pollen pushed upward by hair brushes and exposed for the visitor's benefit, while others have their sticky style branches spread to receive any vitalizing dust brought to them, it follows that quantities of vigorous seed must be set.
"There is a natural rotation of crops, as yet little understood," says Miss Going. " Where a pine forest has been cleared away, oaks come up; and a botanist can tell beforehand just what flowers will appear in the clearings of pine woods. In northern Ohio, when a piece of forest-land is cleared, a particular sort of grass appears. When that is ploughed under, a growth of the golden coreopsis comes up, and the pretty yellow blossoms are followed in their turn by the plebeian rag-weed which takes possession of the entire field."
The charmingly delicate, wiry Garden Tickseed, known in seedsmen's catalogues as Calliopsis (Coreopsis tinctoria), which has also locally escaped to roadsides and waste places eastward, is at home in moist, rich soil from Louisiana, Arizona, and Nebraska northward into Minnesota and the British Possessions. From May to September its fine, slender, low-growing stems are crowned with small yellow composite flowers whose rays are velvety maroon or brown at the base. (Coreopsis = like a bug, from the shape of the seeds.)