2. Verbesina encelioides (Cav.) Benth. & Hook. f. ex A. Gray (golden crownbeard)

Ximenesia encelioides Cav.

V. encelioides ssp. exauriculata (B.L. Rob. & Greenm.) J.R. Coleman

V. encelioides var. exauriculata B.L. Rob. & Greenm.

Pl. 291 d, e; Map 1238

Plants annual with taproots. Stems 7–80(–150) cm long, not winged, densely pubescent with short, mostly straight, loosely appressed hairs, especially toward the tip. Leaves alternate or the lowermost leaves sometimes opposite, short-petiolate or more commonly with a well-defined, long petiole, the base of most or sometimes only the uppermost leaves with small to conspicuous, oblong or obovate to nearly circular auricles of leafy tissue (these rarely absent). Leaf blades 1–14 cm long, narrowly lanceolate (on small plants) or more commonly lanceolate to ovate or ovate-triangular, short-tapered to more or less truncate at the base, angled or tapered to a usually sharply pointed tip, the margins usually coarsely toothed, less commonly finely toothed to nearly entire, the upper surface sparsely to moderately pubescent with appressed hairs, usually appearing green, the undersurface densely appressed-hairy, usually appearing silvery. Inflorescences loose, open clusters with 2–8 heads, sometimes only a solitary head. Involucre 10–20 mm in diameter, broadly cup-shaped, with 12–21 bracts. Involucral bracts 6–23 mm long, narrowly ovate to lanceolate, narrowly oblong-lanceolate, or occasionally linear, ascending to loosely ascending at flowering, the outer surface densely hairy. Chaffy bracts linear, moderately to densely hairy toward the tip. Ray florets 10–15, pistillate (with a 2-branched style exserted from the short tube at flowering), the corolla 10–20 mm long, spreading, yellow. Disc florets 80 to numerous (more than 150), the corolla 2.5–3.5 mm long, yellow. Pappus of the ray florets absent, that of the disc florets of 2 more or less slender awns 0.5–2.0 mm long, usually with fine, upward-pointed barbs, usually shed as the fruit matures. Fruits ascending to somewhat spreading at maturity (forming a more or less hemispherical mass), 4.0–6.5 mm long, the body usually narrowly oblong-obovate, relatively broadly winged, the surface sparsely to moderately pubescent with fine, often pustular-based hairs. 2n=34. May–October.

Introduced, uncommon, sporadic (southwestern U.S. east to Nebraska and Texas; Mexico; introduced sporadically farther north and east in the U.S., also Hawaii, South America, Caribbean Islands, Asia, Mauritius, Australia). Crop fields, railroads, roadsides, and open, disturbed areas.

Coleman (1966) treated V. encelioides as comprising two weakly separable subspecies. He indicated that their ranges in the United States differed, with ssp. encelioides along the Atlantic and Gulf Coastal Plains from eastern Texas to Florida and North to North Carolina, and ssp. exauriculata occupying a range in the southwestern United States. However, in doing so, he (and some subsequent authors) apparently confused the native range of ssp. encelioides, which appears to be native in southernmost Texas but has been treated as introduced in the major floristic works involving the southeastern states (for example, Cronquist, 1980). Both subspecies have a large overlapping range in Mexico. The ssp. encelioides was first reported for Missouri by Coleman (1966), and its distribution and spread into Missouri were discussed by Wagner (1979). It supposedly differs in having most of the petioles with conspicuous, obovate to nearly circular auricles at the base and slightly larger heads, whereas ssp. exauriculata supposedly is characterized by petioles lacking auricles or those of only the upper leaves with relatively small, oblong auricles and slightly smaller heads. Examination of specimens in the Missouri Botanical Garden Herbarium from throughout the range of the species do not support any correlation between these characters, nor do the specimens suggest that there are strong differences in the natural ranges. The size and shape of the leaf auricles is often not possible to ascertain, as many specimens comprise only the upper portions of the plant, and these characters appear to vary more continuously than has been suggested in the literature. The characters involved probably should be regarded merely as part of the overall species variation.