Heads many-flowered; rays pistillate, or wanting. Scales of the involucre imbricated, with scarious margins. Receptacle conical, at least in fruit, naked. Achenes 3–5-ribbed, wingless; pappus a membranaceous crown or border, or none.—Smooth and branching herbs (ours annuals or biennials) with finely divided leaves and single or corymbed heads. Rays white or none; disk yellow. (Named for reputed medicinal virtues.)
M. inodòra, L. Leaves twice-pinnately divided into fine almost filiform lobes; heads large, naked-peduncled, and with many long rays; achenes strongly 3-ribbed; pappus a short crown or border.—(Wild far northward.) Roadsides, Eastport, Maine, Prof. Verrill. Aug. (Adv. from Eu.)
M. discoídea, DC. Low (6–9´ high); leaves 2–3-pinnately parted into short linear lobes; heads rayless, short-peduncled; scales oval, with broad margins, much shorter than the conical disk; achenes more terete; pappus obsolete.—Banks of the Mississippi opposite St. Louis. An immigrant from Oregon, extending eastward and becoming naturalized near railroad stations; also established in N. Europe. July–Sept.
69. CHRYSÁNTHEMUM, Tourn. Ox-eye Daisy.
Heads many-flowered; rays numerous, fertile. Scales of the broad and flat involucre imbricated, with scarious margins. Receptacle flat or convex, naked. Disk-corollas with a flattened tube. Achenes of disk and ray similar, striate, without pappus.—Perennial herbs, with toothed, pinnatifid, or divided leaves, and single or corymbed heads. Rays white; disk yellow. (Old Greek name, χρυσάνθεμον, i.e. golden flower.)
C. Leucánthemum, L. (Ox-eye or White Daisy. White-weed.) Stem erect, nearly simple, naked above and bearing a single large head; root-leaves spatulate, petioled, the others partly clasping, all cut or pinnatifid-toothed; scales of the involucre with rusty-brown margins. (Leucanthemum vulgare, Lam.)—Fields and meadows; abundant eastward. June, July. A pernicious weed, with large and showy heads. It occurs with abortive, deformed, or tubular and laciniate rays. (Nat. from Eu.)
C. Parthènium, Pers. (Feverfew.) Tall, branched, leafy; leaves twice-pinnately divided, the divisions ovate, cut; heads corymbed, rather small. (Leucanthemum Parthenium, Godron.)—Escaped from gardens in some places. (Adv. from Eu.)
Heads many-flowered, nearly discoid; flowers all fertile, the marginal chiefly pistillate and 3–5-toothed. Involucre imbricated, dry. Receptacle convex, naked. Achenes angled or ribbed, with a large flat top; pappus a short crown.—Bitter and acrid strong scented herbs (ours perennial), with 1–3-pinnately dissected leaves, and corymbed heads. Flowers yellow; in summer. (Name of uncertain derivation.)
T. vulgàre, L. (Common Tansy.) Stem (2–4° high) smooth; leaflets and the wings of the petiole cut-toothed; corymb dense; pistillate flowers terete, with oblique 3-toothed limb; pappus 5-lobed.—Var. críspum has the leaves more cut and crisped.—Escaped from gardens to roadsides; Atlantic States. (Nat. from Eu.)