Involucre many-leaved, longer than the chaffy leafy-tipped and pointed bracts among the densely capitate flowers; each flower with a 4-leaved calyx-like involucel investing the ovary and fruit (achene). Calyx-tube coherent with the ovary, the limb cup-shaped, without a pappus. Corolla nearly regular, 4-cleft. Stamens 4, inserted on the corolla. Style slender.—Stout and coarse biennials, hairy or prickly, with large oblong heads. (Name from διψάω, to thirst, probably because the united cup-shaped bases of the leaves in some species hold water.)
1. D. sylvéstris, Mill. (Wild Teasel.) Prickly; leaves lance-oblong; leaves of the involucre slender, longer than the head; bracts (chaff) tapering into a long flexible awn with a straight point.—Roadsides; rather rare. (Nat. from Eu.) Suspected to be the original of
2. D. Fullònum, L., the Fuller's Teasel, which has a shorter involucre, and stiff chaff to the heads, with hooked points, used for raising a nap upon woollen cloth; it has escaped from cultivation in some places. (Adv. from Eu.)
(Addendum) 2. SCABIOSA, Tourn. Scabious.
Characters of Dipsacus, but the green leaves of the involucre and involucels not rigid nor spinescent. (Name from scabies, the itch, from its use as a remedy.)
S. austràlis, Wulf. Perennial, sparsely branched, nearly glabrous, 1½–3° high; leaves narrowly lanceolate to linear, the lower oblanceolate, slightly toothed or entire; heads short-oblong; calyx obtusely short-lobed; corolla pale blue.—Central N. Y. and Penn.; rare. (Adv. from Eu.)
Order 55. COMPÓSITÆ. (Composite Family.)
Flowers in a close head (the compound flower of the older botanists), on a common receptacle, surrounded by an involucre, with 5 (rarely 4) stamens inserted on the corolla, their anthers united in a tube (syngenesious).—Calyx-tube united with the 1-celled ovary, the limb (called a pappus) crowning its summit in the form of bristles, awns, scales, teeth, etc., or cup-shaped, or else entirely absent. Corolla either strap-shaped or tubular; in the latter chiefly 5-lobed, valvate in the bud, the veins bordering the margins of the lobes. Style 2-cleft at the apex (in sterile flowers usually entire). Fruit seed-like (achene), dry, containing a single erect anatropous seed, with no albumen.—An immense family, in temperate regions chiefly herbs, without stipules, with perfect, polygamous, monœcious or diœcious flowers. The flowers with a strap-shaped (ligulate) corolla are called rays or ray-flowers; the head which presents such flowers, either throughout or at the margin, is radiate. The tubular flowers compose the disk; and a head which has no ray-flowers is said to be discoid. When the head contains two sorts of flowers it is said to be heterogamous; when only one sort, homogamous. The leaves of the involucre, of whatever form or texture, are termed scales. The bracts or scales, which often grow on the receptacle among the flowers, are called the chaff; when these are wanting, the receptacle is said to be naked.—The largest order of Phænogamous plants. The genera are divided by the corolla into three series, only two of which are represented in the Northern United States. The first is much the larger.
Systematic Synopsis.
Series I. TUBULIFLORÆ.