For the past several weeks I’ve been busy searching my Penstemon library for information we’ll use in an analysis to be presented at the Botany 2014 meeting. I have a nice assortment of taxonomic treatments (floras, monographs, and species descriptions) as well as horticultural references, conservation papers, and pollination ecology studies.
It’s been a lot of fun to review the morphological trends in this very diverse genus, and we’ve just recently established the time frame for diversification rates (this genus is very young!) from a new phylogenetic analysis. It’s all very exciting for my lab group, and I’m very much looking forward to presenting all this cool information next month. Paul Blischak is running some cool analyses with the sequence data from my 2006 study, and we’ll be charting some of the evolutionary trends on the new phylogenetic tree we’ll present at Botany 2014.
The more I study this genus, the more amazed I am at how fast evolution can occur in plants. Some of the important selection pressures for speciation in Penstemon involve pollination ecology and adaptation to specific types of habitats. As I’ve been reviewing Francis Pennell’s monographs, I’ve been reminded that he made some pretty significant predictions about evolutionary trends in Penstemon, many of which hold up under rigorous phylogenetic testing. The same goes for many of David Keck’s hypotheses.
In this day and age of digital library resources, I’m gratified that my collection of Penstemon literature is so rich (stored in old fashioned filing cabinets, no less). Many of the papers were published in the early 1900s. I inherited quite a huge chunk of literature from Richard M. Straw in the form of original reprints from his file cabinets, but I’ve been collecting articles, floras, monographs and other papers on Penstemon since the late 1980s. What is very frustrating to me is the inconsistency of treatments from author to author. The best resource out there in terms of a flora treatment comes from Noel Holmgren’s Intermountain Flora contribution. About 1/3 of the genus is covered in the Intermountain Flora. Craig Freeman is writing the Penstemon treatment of the Flora of North America. I sure hope it’s as thorough as Noel’s treatment for the Intermountain Flora…