Scrophulariaceae of the Central Rocky Mountain StatesFrancis W. Pennell · First published 1920 · Latest edition 2018Open the Tome
A new Indian Paint-brush from the Mogollon Plateau of Arizona (Castilleja: Scrophulariaceae)Francis W. Pennell · First published 1951Open the Tome
A new velvety monkey-flower from California (Mimulus: Scrophulariaceae)Francis W. Pennell · First published 1951Open the Tome
Taxonomy and distribution of Aragoa, and its bearing on the geological history of the Northern AndesFrancis W. Pennell · First published 1938Open the Tome
Scrophulariaceae of Eastern Temperate North AmericaFrancis W. Pennell · First published 1935Open the Tome
The Sorophulariaceae of eastern temperature North AmericaFrancis W. Pennell · First published 1935Open the Tome
A note on the distribution of Synthyris schizanthaFrancis W. Pennell · First published 1934Open the Tome
Scrophulariaceae of the northwestern United StatesFrancis W. Pennell · First published 1934Open the Tome
Scrophulariaceae of the Southeastern United StatesFrancis W. Pennell · First published 1920Open the Tome
