The flowers grow in very compact, flat-topped clusters at the top of the stem. Each flower-head has a centre of short, tubular, yellowish florets that turn brown or grayish as they grow old; they are surrounded by from four to six round, white rays.
Yarrow is a very hardy plant; we may find it thriving beside roads where the dust has killed nearly ever other living thing. Its leaves have a strong, not unpleasant, aromatic odor.
(B) Mayweed; Chamomile (Anthemis Cotula) (European) is also a common weed found by the wayside in company with the last species. The stem is very branchy, 8 to 20 inches high. The leaves are very finely divided. The strong, unpleasant odor of the foliage will at once correct the impression that it may be a Daisy.
(A) Sneezeweed (Helenium autumnale) is a beautiful rather odd plant that brightens meadows and swamps during August and September. The stem is rather stout, smooth, and branching; it ascends from 2 to 6 feet. Alternating along the stem are numerous ovate, pointed, sharply toothed, bright green leaves.
It is the blossoms that attract our attention for, besides being very handsome, they are unusual in form. The hemispherical centre is composed of closely packed tubular florets and is surrounded by a number of broad, toothed, golden-yellow rays; the heads have an expanse of 1 to 2 inches. Both the tubular and the yellow pistillate rays are fertile.
(B) Tansy; Bitter Buttons (Tanacetum vulgare) (European) is abundant everywhere about houses and along roads, from the Atlantic to the Rocky Mountains.
The foliage is very bitter and is the foundation of many an old-fashioned remedy. The flowers grow in flat-topped clusters and are composed of round discs, or “buttons,” of tubular florets only. It is a species not to be mistaken; it has an appearance, an odor, and a taste of its own. It blooms from July until September.
(A) Golden Ragwort (Senecio aureus). In late March and early April, Ragwort shows simply a tuft of stemmed, heart-shaped leaves, resembling those of [Violets]. A little later a stem ascends from the perennial root; a slender, tough, angular, twisting stem that finally reaches heights of 1 to 3 feet. During May and June they carry at their summit a loose cluster of bright, orange-yellow flowers. Each flower is composed of but 8 to 12 narrow, orange-yellow rays, surrounding a central cluster of tubular florets of brownish orange.