The Manual of the Botany of the Northern United States / Including the District East of the Mississippi and North of North Carolina and Tennessee

by Asa Gray

35. Inula. Heads large, many-flowered. Flowers yellow. Stout perennial.

Tribe V. HELIANTHOIDEÆ. Heads radiate or discoid. Involucre not scarious (nut-like in fruit in n. 43, 44). Receptacle chaffy. Pappus never capillary, sometimes none. Anthers not caudate. Style-branches truncate or hairy-appendaged.

[*] 1. Heads radiate (obscurely so in n. 41, sometimes discoid in n. 36), the ray pistillate and fertile, the disk perfect but sterile.

[+] Achenes turgid, triangular-obovoid; pappus none.

36. Polymnia. Involucral scales in 2 rows, the 5 outer leaf-like, the inner small.

[+][+] Achenes flattened dorsally (obcompressed).

37. Silphium. Achenes wing-margined, in several rows; pappus none or 2 teeth. Scales thick, in several rows.

38. Berlandiera. Achenes wingless, 5–12 in one row, without pappus. Inner involucral scales obovate, outer smaller and more foliaceous. Western.

39. Chrysogonum. Achenes wingless, about 5; pappus a one-sided 2–3-toothed crown. Inner scales 5, chaff-like, the 5 outer longer and leaf-like.

40. Engelmannia. Achenes wingless, 8–10; pappus a scarious hispid crown. Outer scales (about 10) leaf-like, inner coriaceous with green tips. Western.