3. H. tenuifòlius, Pursh. Slightly tomentose or glabrate, leafy, 1–2° high; divisions of the leaves narrowly linear or filiform, revolute; involucral scales obovate-oblong; achenes long-villous.—Neb. to Ark. and Tex.
Heads many-flowered; rays several, wedge-oblong, 3-toothed, pistillate. Scales of the hemispherical involucre ovate or lanceolate, membranaceous or coriaceous, nearly equal, appressed in 2 or 3 ranks, little shorter than the disk. Receptacle hemispherical or conical, naked. Achenes top-shaped, densely silky-villous; pappus of 5 or more ovate or lanceolate very thin chaffy scales.—Low herbs, with narrow alternate leaves, dotted or sprinkled with resinous atoms as in the next genus and bitter-aromatic; the solitary heads terminating scapes or slender naked peduncles; flowers yellow. (Name a diminutive of Actinea, from ἀκτίς, ray.)
[*] Involucre of numerous distinct not rigid scales; leaves entire.
1. A. linearifòlia, Torr. & Gray. Annual or biennial, villous or glabrate, 1° high or less, simple or branched; leaves linear; peduncles filiform.—S. Kan. to La., and Tex.
2. A. acaùlis, Nutt. Perennial, densely cespitose, the branches of the caudex short and thick, with scape-like peduncles, canescently villous or silky; leaves spatulate to linear, short.—Hills and plains bordering the Rocky Mts. and scarcely reaching our limits; the var. glàbra, Gray (A. scaposa, var. glabra, Man.), a greener glabrate form, has been found on an Indian mound near Joliet, Ill. The less densely cespitose A. scapòsa, Nutt., more loosely villous and the caudex with more slender branches, is probably in S. Kan.
[*][*] Scales rigid, in 2 rows, the outer connate at base; leaves ternately parted.
3. A. odoràta, Gray. Annual, 1–2° high, branching, leafy, somewhat floccose-woolly; heads small, scattered; leaves 1–3-pinnately divided, the lobes filiform.—Central Kan. to Tex., and westward.
63. HELÈNIUM, L. Sneeze-weed.
Heads many-flowered, radiate; rays several, wedge-shaped, 3–5-cleft, fertile or rarely sterile. Involucre small, reflexed, the scales linear or awl-shaped. Receptacle globose or oblong, naked. Achenes top-shaped, ribbed; pappus of 5–8 thin and 1-nerved chaffy scales, the nerve usually extended into a bristle or point.—Erect, branching herbs (ours perennial), with alternate leaves decurrent on the angled stem and branches, which are terminated by single or corymbed (yellow, rarely purple) heads; often sprinkled with bitter aromatic resinous globules. (The Greek name of some plant, said to be named after Helenus, son of Priam.)