1. Inula helenium L. (elecampane)

Pl. 294 a–c; Map 1243

Plants perennial herbs from a thickened rootstock. Stems 40–120(–200) cm long, erect or ascending, usually unbranched below the inflorescence, with fine, spreading hairs, not spiny or prickly. Leaves alternate and sometimes also basal, simple, not spiny or prickly, the blade with the margins irregular and finely toothed, the upper surface with sparse, spreading hairs, the undersurface densely pubescent with fine, velvety hairs. Lowermost leaves long-petiolate, the blade 25–50 cm long, 8–20 cm wide, elliptic, tapered at the base, tapered to a sharply pointed tip, grading to the upper leaves, these sessile, clasping the stem, ovate, the base cordate, the tip narrowed or tapered to a sharp point. Inflorescences relatively few-headed, axillary and terminal, the heads solitary or in small, loose clusters, sometimes appearing as small panicles. Heads radiate. Involucre 2.0–2.5 cm long, 3–5 cm in diameter, bell-shaped to more or less hemispherical, with 2–4 series of overlapping bracts, these loosely appressed to somewhat spreading, all but the innermost series narrowly ovate to elliptic-ovate or oblong-ovate, not spiny or tuberculate, the outer surface and margins with fine, velvety hairs, green, but often with lighter, papery margins, these sometimes becoming reddish brown, those of the innermost series linear to narrowly oblong-lanceolate, glabrous, membranous to papery, reddish brown to purple, rarely lighter colored. Receptacle flat to slightly convex, naked. Ray florets numerous, pistillate, slender, the corolla 1.5–2.5 cm long, yellow. Disc florets numerous, perfect, the corolla 8–12 mm long, yellow. Pappus (of ray and disc florets) of a single series of numerous capillary bristles, these 6–9 mm long, more or less fused at the base, with short, fine, ascending awns. Stamens with the filaments not fused together, the anthers fused into a tube, each tip with a short, often indistinct appendage, each base prolonged into a pair of slender, tail-like lobes. Style branches flattened, each with a stigmatic line along each inner margin that is continuous around the rounded tip, hairy. Fruits 4–5 mm long, narrowly oblong in outline, more or less 4-angled or square in cross-section, not winged, not beaked, tan to light brown, somewhat shiny, glabrous. 2n=20. June–September.

Introduced, uncommon and sporadic (native of Europe, widely but sporadically escaped from cultivation in the northeastern and western U.S. and adjacent Canada). Old fields, roadsides, and open, disturbed areas.

Elecampane is not as frequently grown as it once was. Early settlers used an extract of the mucilaginous, thickened root to treat pulmonary diseases and various other ailments, including upset stomach, diarrhea, worms, sciatica, and skin ailments. The rootstock, which is rich in inulin (a source of fructose) also has been cooked and candied and used to flavor vermouth and absinthe (Steyermark, 1963; Arriagada, 1998). Native Americans, who got plants from settlers, used the species as a gynecological aid, as heart medicine, and to treat domesticated animals (Moerman, 1998). The roots contain alantolactone, an analgesic with sedative properties.

The cultivated I. britannica L. (British yellowhead) has become established outside cultivation sporadically in New York and adjacent Canada. This aggressive garden perennial was collected recently as a weed in a flower bed in St. Louis County. Eventually it may become naturalized in the state. Inula britannica is a biennial or short-lived perennial with shorter stems and smaller leaves and heads than those found in I. helenium.