Phyllis is one of the nation's preeminent wetland field biologists for more than four decades. She was a co-editor of the University of California Press's California Natural History Guides, and a Fellow of the California Native Plant Society where she edited the Society's journal, Fremontia, for many years. Phyllis served as one of the first California Coastal Commissioners and a founder of the Marin Agricultural Land Trust (MALT) which has protected over 40% of the County's farmland through conservation easements.