Anthidium tenuiflorae Cockerell, 1907
Alliaceae: Allium cernuum. Asteraceae: Aster foliaceus var. apricus, A. occidentalis, A. occidentalis var. yosemitanus; Balsamorhiza sp.; Chrysothamnus depressus; Cirsium sp.; Erigeron pumilus; Gaillardia pinnatifida; Senecio sp.; Solidago confinis. Boraginaceae: Phacelia argillacea, P. frigida, P. hastata, P. heterophylla, P. leptosepala, P. leucophylla. Brassicaceae: Streptanthus tortuosus. Caryophyllaceae: Arenaria kingii. Crassulaceae: Sedum lanceolatum, S. obtusatum. Fabaceae: Astragalus calycosus, A. kentrophyta, A. miser, A. montii, A. tenellus; Lotus argophyllus, L. davidsonii, L. nevadensis; Lupinus breweri, L. confertus, L. duranii, L. lepidus var. lobbii; Medicago sativa; Melilotus officinalis; Trifolium oliganthum; Vicia villosa. Lamiaceae: Monardella odoratissima; Poliomintha incana; Salvia dorrii. Onagraceae: Epilobium andenocaulon var. parishii; E. ciliatum. Plantaginaceae: Penstemon secundiflorus, P. unilateralis. Rosaceae: Horkelia fusca; Ivesia santolinoides; Potentilla glandulosa, P. gracilis; Rubus idaeus.
The female of this species is easily recognized by the weakly convex clypeus, pale sternal scopa, smooth and shiny terga with coarsely and densely punctate depressed marginal zones, and distally truncate T6 with median emargination weakly sinuate or absent. The male resembles that of A. emarginatum and A. platyfrons in the broad lateral lobe of T7 and the apical brush of S4 with long, black hairs; it can be separated from those species by the narrower lateral lobe of S6 with outer margin usually concave (lobe appearing digitiform) and S8 with a longer and narrower apical process.
This is perhaps the most widespread Anthidium in North America, ranging from Alaska, USA to Baja California, Mexico. It is found primarily at high elevations.