25 juin 2019
Albert Everett Wieslander, « Half mile N. of North Star Mine. Semidense shrub-tree type of ponderosa pine, Arctostaphylos viscida, Ceanothus integerrimus. Assoc spp.: Ceanothus prostratus, Chamaebatia foliolosa. Nevada County. », Berkeley Library Digital Collections, ID : 10670/1.m7qdki