California

Plagiobryoides vinosula (Cardot) J.R.Spence (BRYACEAE).—Santa Clara County, Diablo Range, Henry W. Coe State Park, found near the intersection of Vasquez and Dormida trail beside Cañada de la Dormida Creek, 37.09723°, –121.38288°, 350 m. On mesic soil of creek bank with Scleropodium touretii (Brid.) L.F.Koch and Didymodon tophaceus (Brid.) Lisa in mixed riparian woodland consisting of Platanus racemosa Nutt., Pinus sabiniana Douglas, Aesculus californica (Spach) Nutt., Quercus douglasii Hook. & Arn., Umbellularia californica (Hook. & Arn.) Nutt., Heteromeles arbutifolia (Lindl.) M.Roem., and Frangula californica (Eschsch.) A.Gray. 12 March 2022; J. McLaughlin 1017 (SJSU).—Stanislaus County, Diablo Range, Henry W. Coe State Park, Orestimba Wilderness Area, found in an unnamed canyon adjacent to Red Creek Road and Bear Mtn. Road draining into Red Creek, 37.235°, –121.42516°, 453 m, on soil over partially submerged rock with Scleropodium occidentale B.E.Carter and Plagiobryoides sp. in an open riparian woodland consisting of Quercus wislizeni A.DC., Pinus sabiniana Douglas, and Aesculus californica (Spach) Nutt. recovering from 2021 SCU Lightning Complex Fire 9 April 2022; J. McLaughlin 1243 with James Shevock (SJSU).

Previous knowledge. Plagiobryoides vinosula is restricted to western North America and is best represented in the Mojave Desert and the southern Sierra Nevada mountain ranges in California, and the great basin of Nevada. It has also been sparsely collected in northern California, Wyoming, Colorado, Arizona, and Texas, USA. It has been documented from the Baja California peninsula and the state of Puebla, Mexico (CNABH 2022). In California, it occurs on saturated soils or soil over granitic and calcareous rocks in springs and riparian zones from 800–2200 m CNABH 2022; Spence 2014).

Significance. This is the first collection of Plagiobryoides vinosula in both Santa Clara and Stanislaus Counties, as well as along the Diablo Range, representing this species' eastern-most presence in the Coast Ranges of California. These collections also represent an extension of this species' lower elevational range limit, from 800 m to 350 m. The state of California Department of Fish and Wildlife has listed this species as G3G4/S3S4 putting it at a low to moderate risk of extinction and extirpation in California. CNPS has given this species a California Rare Plant Rank of 4.2 putting it on a watchlist due to the moderate threat and limited distribution of this species in the state (California Natural Diversity Database 2023). It is likely that this species has been historically overlooked and/or misidentified. This report along with further collecting will assist in improving the taxon's conservation status.