Heliomeris is a small genus of annual and perennial herbs in the family Asteraceae (order Asterales), commonly known as false goldeneyes. The genus comprises five species native to the western United States and northern Mexico, with one outlying species (H. obscura) restricted to a remote area straddling the Mexican states of Puebla and Oaxaca.
Plants produce sunflower-like radiate flower heads with yellow ray florets. Heliomeris is distinguished from related genera within the subtribe Helianthinae by two anatomical traits: the achenes are glabrous and completely lack a pappus, and the involucre is composed of only two series of phyllaries (bracts).
The genus was circumscribed in its modern sense following molecular phylogenetic studies by Schilling & Panero in 2002 and 2011. Using nuclear ITS, ETS, and chloroplast DNA sequences, they demonstrated that the traditionally broad genus Viguiera Kunth does not form a natural (monophyletic) group. Their revision redistributed Viguiera species across at least nine segregate genera, with Heliomeris Nutt. absorbing a portion of those species. Notable members include H. multiflora (showy goldeneye), one of the more widespread species ranging from San Luis Potosí north to Montana, and H. longifolia (longleaf false goldeneye), found across much of Mexico's Sierra Madre and the southwestern United States.
Etymology
The name Heliomeris derives from the Greek helios (sun) and meris (part or portion), alluding to the sunflower-like radiate flower heads characteristic of the genus.
Distribution
Heliomeris species are native to the western United States and northern Mexico, with the majority occurring in states bordering the Sierra Madre Occidental — including Arizona, New Mexico, Utah, Colorado, Nevada, Texas, and Mexican states such as Sonora, Chihuahua, Durango, and Jalisco. H. multiflora extends the northern range to Montana. H. obscura is an outlier, endemic to the border area of Puebla and Oaxaca in southern Mexico.
Taxonomy Notes
Heliomeris belongs to the subtribe Helianthinae within Asteraceae. Its current delimitation follows Schilling & Panero (2002, 2011), who used molecular phylogenetics (nuclear ITS, ETS, and cpDNA) to show that Viguiera Kunth — a large, historically lumped genus — is polyphyletic. Their revision split Viguiera into at least nine segregate genera, including Heliomeris Nutt. GBIF recognizes 5 accepted species in the genus.
