Page:Manual of the New Zealand Flora.djvu/311

Ageratum.]

Florets all ligulate and hermaphrodite, and hence homogamous. Sap milky. Consists of one tribe,.

Erect herbs or rarely shrubs. Leaves opposite or the upper alternate. Heads usually corymbose, homogamous and discoid. Involucre campanulate; bracts 2–3-seriate, linear, subequal. Receptacle flat or nearly so, naked or with deciduous scales among the florets. Florets all tubular, hermaphrodite, equal; corolla-limb regularly 5-cleft. Anthers obtuse at the base. Style-branches elongate, obtuse. Achenes 5-angled. Pappus of 5 free or connate scales, or of 10–20 narrower ones.

1. A. conyzoides, ''Linn. Sp. Plant.'' 839.—A stout erect branching annual herb 1–3 ft. high, more or less clothed with spreading hairs. Leaves opposite, 1–3 in. long, ½–2 in. broad, ovate, obtuse or subacute, petiolate, crenate or crenate-serrate. Flower-heads small, ¼ in. diam., in dense terminal corymbs. Involucre nearly glabrous; bracts striate, acute, in about 2 rows. Florets numerous, blue or white. Achenes black, glabrous or slightly hispid. Pappus of 5 awned lanceolate scales.—D.C. Prodr. v. 108; ''Benth. Fl. Austral.'' iii. 462; ''Cheesem. Trans. N.Z. Inst.'' xx. (1888) 169; Kirk, Students Fl. 256.

Small perennial herbs. Leaves often all radical. Scapes slender, unbranched. Heads solitary, small, heterogaraous. Involucre short, almost hemispherical; bracts in about two rows, with