66. ÁNTHEMIS, L. Chamomile.
Heads many-flowered, radiate; rays pistillate or (in n. 1) neutral. Involucre hemispherical, of many small imbricated dry and scarious scales shorter than the disk. Receptacle conical, with slender chaff at least near the summit. Achenes terete or ribbed, glabrous, truncate; pappus none or a minute crown.—Branching strong-scented herbs, with finely pinnately dissected leaves and solitary terminal heads; rays white; disk yellow. (Ἀνθεμίς, the ancient Greek name of the Chamomile.)
A. Cótula, DC. (May-weed.) Annual, acrid; rays mostly neutral; receptacle without chaff near the margin; pappus none; leaves finely 3-pinnately dissected. (Maruta Cotula, DC.)—Common by roadsides. (Nat. from Eu.)
A. arvénsis, L. (Corn Chamomile.) Pubescent annual or biennial, resembling May-weed, but not ill-scented; leaves less finely 1–2-pinnately parted; chaff of the receptacle lanceolate, pointed; pappus a minute border.—Waste places; rare. (Adv. from Eu.)
A. nóbilis, L. (Garden Chamomile.) More downy and perennial, pleasantly strong-scented; sterile shoots depressed or creeping; leaves very finely dissected; chaff of the receptacle blunt; pappus none.—Established near Lewiston, Delaware, Nuttall. (Adv. from Eu.)
67. ACHILLÈA, L. Yarrow.
Heads many-flowered, radiate; the rays few, fertile. Involucral scales imbricated, with scarious margins. Receptacle chaffy, flattish. Achenes oblong, flattened, margined; pappus none.—Perennial herbs, with small corymbose heads. (So named because its virtues are said to have been discovered by Achilles.)
1. A. Millefòlium, L. (Common Yarrow or Milfoil.) Stems simple; leaves twice-pinnately parted; the divisions linear, 3–5-cleft, crowded; corymb compound, flat-topped; involucre oblong; rays 4–5, short, white (sometimes rose-color).—Fields and hills; common. Green and more glabrate in fields in the Atlantic States, and perhaps in such cases introduced. Aug. (Eu.)
A. Ptármica, L. (Sneezewort.) Leaves simple, lance-linear, sharply serrate with appressed teeth; corymb loose; rays 8–12, much longer than the broader campanulate involucre; flowers white.—Mass., Mich., etc.; rare. Apparently indigenous on the Lower St. Lawrence. (Adv. from Eu.)
68. MATRICÀRIA, Tourn. Wild Chamomile.