Single Record

Species: Packera thurberi [Packera tridenticulata] [Senecio oblanceolatus] [Senecio remifolius] [Senecio thurberi] [Senecio neomexicanus]

Counties: Alamosa, Conejos, Costilla, Hinsdale, Mineral, Rio Grande, Saguache, Archuleta, San Juan

Passes: Carnero, Cochetopa, Cumbres, Poncha, South, Spring Creek, Stony, Wolf Creek

PhotoRecords: YES Rich Haswell: Mineral Co, Willow Creek above Creede 6 June 2017

Comments: Taxonomically Thurber's groundsel is a vexed species. Following POWO and Allred et al. (2020), we separate Packera thurberi from P. neomexicana, and we make P. tridenticulata a synonym of P. thurberi. So subscribed, P. thurberi is a found everywhere in Watershed except for the Lower Basin. Note that the species was defined by B. L. Turner in 2008, so that most earlier voucher specimens are called "Packera tridenticulata. The species follows the Rio Grande drainage on into the northern border counties of New Mexico, but not farther south. The USA distribution is eastern Great Plains and the Central Rockies states of Wyoming, Colorado, and northern New Mexico. Ackerfield (2022) also separates P. neomexicana (with tomentose leaves) and P. thurberi (with glabrous leaves) but shows no distribution map for the second. Specimens of P. thurberi from the Watershed seem to fall into two forms, one with shorter basal leaves flaring out into an apex with three distal teeth (Weber & Wittman 2012 call this the "characteristic" form); the other with long, narrow basal leaves, entire or irregularly dentate. For recent Watershed occurrences of the second form, see iNaturalist observations #80611732 (2021), #97159055 (2021), and #166714192 (2023). The variation may be partly due to hybridization with Packera neomexicana var. mutabilis, also common and sympatric with P. thurberi.