Sampangi, R.K.; Almeyda, C.; Druffel, K.L.; Krishna Mohan, S.; Shock, C.C.; Pappu, H.R. 2009. First report of natural infection of Penstemon acuminatus with cucumber mosaic virus in the Treasure Valley of Idaho and Oregon. Plant Disease: An International Journal of Applied Plant Pathology. 93(7): 762.