Penstemon (Plantaginaceae) for Flora of North America
In support of the Flora of North America project, herbarium and field studies were initiated in 2009 as part of a multi-year effort leading to the preparation of a taxonomic treatment for the genus Penstemon (Plantaginaceae). Nearly 30,000 specimens from more than 30 herbaria were examined, and nearly 1,000 specimens representing 100 species were collected, studied, and measured to prepare descriptions and keys for the 239 species of Penstemon in North America north of Mexico. That treatment, the first to integrate information for all the species in the U.S. and Canada, was published in FNA Volume 17 in 2019. Since 2019, more specimens have been gathered and several ancillary projects are underway, including a comprehensive survey of the cytological data for the genus and morphometric studies of several species complexes.