Since 1997 I’ve been actively working on the systematics of Costaceae, including both monographic and phylogenetic research. Together with Paul and Hiltje Maas, we completed a monograph of African Costus species (Maas et al, 2016; Blumea – can be downloaded here) and are in the process of generating a well- resolved phylogeny for the African species including newly described taxa. This project is led by Will Iles and Kelsi
e Morioka and includes hyb-seq data from nuclear regions for all Costus with accessions focused on African taxa, including multiple accessions for those species with questionable monophyly. Funding from National Geographic generously contributed to this effort.
“Team Maas” is now working together to produce a monograph of all New World Costaceae, including Costus, Dimerocostus, 
Monocostus and Chamaecostus. This is a continuation on work published by Shayla Salzman et al. (Systematic Botany 2015) for which we received the Grady Webster Award from ASPT for the most influential paper in systematic botany. Dave Skinner and Thiago Andre are both major contributors to this massive undertaking, with Dave’s field-based expertise in everything neotropical Costus and Thiago’s expertise in
Costaceae phylogenetics and speciation. Prior to the revision, we published 18 new species to help clarify some of the taxonomic issues (Maas et al., 2023). The full revision will be published jointly with a phylogeny, testing the monophyly of many of the enigmatic New World Costus.
With expertise of Research Associate Chodon Sass we developed NGS baits for nuclear genomic regions and are using extractions from herbarium specimens and new wild collections to include broad biogeographic sampling for widespread species with questionable delimitation and to include type species where possible, particularly for areas in which the taxonomy is uncertain. Incoming graduate student Clarice Guan and Postdoctoral Scholar Eugenio Valderrama perfected historical DNA extraction techniques to build libraries for over 350 accessions of new world Costus. With these data, we were able to investigate the role of biogeography in patterns of floral diversity, both within and between species, and explore genetic underpinnings of Costus biodiversity as published in Frontiers in Plant Science (Valderrama et al. 2022). Follow us on twitter as #TeamCostus and #NWCostus and check out a recent blog post about Dave Skinner’s participation as a member of the team. 
In addition to our work on Costus phylogenetics, we continue to investigate the role of development in the evolution of novel phenotypes associated with pollinators (Specht et al. 2012). This work is continuing with Dr. Ana Almeida and her students at California State University, East Bay. We are using comparative genomics methods to study selection and the mechanisms underlying the evolution of bee and bird pollination syndromes. You can see a poster presented by Masters Students Nik Grunder: Nik_poster_final-1kfdut1