Heterotheca fulcrata (E.L. Greene) Shinners is a Rocky Mt. cordillera species in the western U.S. occurring at lower to mid elevations. Margins of distal leaves are usually hispido-strigose; some or all heads are subtended by 1+ ovate to lanceolate leaf-like bracts, distinct from distal leaves and usually surpassing heads, obscure in narrow-leaved, hairy plants.
Leaves and stems moderately to densely short-strigose, eglandular or nearly so (small leaves sometimes nearly white); Colorado, New Mexico, Utah, Wyoming var. amplifolia (Rydb.) Semple
Distal cauline leaf faces sparsely to moderately hispido-strigose, moderately stipitate-glandular; leaflike bracts subtending heads not well differentiated from linear-ovate to -lanceolate distal leaves (12–22 mm); involucres 5.7–8.4 mm; ray laminae 7.3–11 mm (averaging 9.6 mm); e Nevada to trans-Pecos Texas, adjacent Mexico var. arizonica Semple
Leaves and stems sparsely to moderately hispido-strigose and stipitate-glandular; Front Range, Colorado, se Wyoming, mountains of e Nevada, Utah, n, w Arizona, s New Mexico, n Mexico var. fulcrata
Distal margins of distal most leaves abundantly long-hispido-strigose; leaf faces moderately hispido-strigose, moderately stipitate-glandular; Arizona, New Mexico, Texas, adjacent Mexico var. senilis (Woot. & Standl.) Semple
Nesom (2007, 2020) divided H. fulcrata as presented here into 7 nearly allopatric species: H. fulcrata restricted to the southern portion of the range given by Semple (1996) in SE Arizona and adjacent Mexico, S New Mexico, and trans Pecos, Texas. Het. fulciens Nesom occurs in Nevada, SW Utah, and N and central Arizona. Het. marcbakeri Nesom is very rare in Yavapai Co, AZ. Het. arizonica (Semple) Nesom occurs in Arizona, SW New Mexico and adjacent Mexico, and trans Pecos Texas. Het. niditula (Woot. & Standl.) Nesom occurs in the mountains of the west-central New Mexico and adjacent Arizona Het. cryptocephala (Woot. & Standl.) Nesom occurs in the White Mts. of southcentral New Mexico. Het. resinolens Nesom occurs in the Rocky Mts. in Colorado.
A large sample polygenomic DNA analysis is needed to resolve species/variety limits in the S. fulcrata complex.
Last revised 30 April 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-8. Heterotheca fulcrata. 1. var. senilis, habit, Semple & Heard 8173, Culberson Co., Texas. 2. var. arizonica, Semple & Heard 7923, Gila Co., Arizona. 3. var. amplifolia, upper stem leaves and inflorescence, cult. WAT. 4-5. var. fulcrata, stem and leaf, Semple et al. 6538, Boulder Co., Colorado. 6. var. fulcrata, Heads and subtending leaves, Semple & Brouillet 7255, Teller Co., Colorado. 7. var. amplifolia, head and subtending leaves, Hogan 1969 WAT, Boulder Co., Colorado. 8. var. arizonica, leaves and heads, S & H 7923.