POACEAE

POACEAE View in CoL View at ENA

North American Andropogon : new generic concepts and new names in Anatherum Primary authors:Alan S. Weakley, Edwin L. Bridges, Richard J. LeBlond, Steve L. Orzell, Bruce A.Sorrie, and Joseph K. Wipff

Vorontsova et al. (2023) made a compelling case for the recognition of Andropogon L. sect. Leptopogon Stapf at generic rank, as Anatherum P. Beauv. , in order to make an important step towards the recognition of monophyletic genera in the subtribe Andropogoninae . Their phylogenetic results, along with those of other recent analyses ( Arthan et al. 2017; Welker et al. 2020), suggest that the phylogenetic topology would allow members of sect. Leptopogon to be included in a monophyletic Andropogon typified by Andropogon distachyos L.(the conserved type of Andropogon , superseding via conservation the previously designated lectotype, Andropogon virginicus L.), if Andropogon were broadened to the same circumscription as the subtribe Andropogoninae , thus including genera such as Schizachyrium Nees , Themeda Forssk. , Hyparrhenia Andersson ex E. Fourn. , Elymandra Stapf , Monocymbium Stapf , and others; such a c ourse seems retrogressive and unpopular. Vorontsova et al. (2023) also identified morphological features distinctive of Anatherum and discussed its center of diversity in the Americas.

For North America north of Mexico, the removal of species previously placed in sect. Leptopogon to genus Anatherum leaves Andropogon gerardi Vitman and Andropogon hallii Hackel as the only remaining members of Andropogon ( Campbell 2003) . These “big bluestem” species are apparently of allopolyploid origin, probably involving ancestors from two currently recognized genera ( Nagahama & Norrmann 2012; Estep et al. 2014; Vorontsova et al. 2023); this suggests they may warrant removal from Andropogon as well, likely into a new genus, but we follow Vorontsova et al. (2023) in retaining them in Andropogon for now until definitive taxonomic solutions are developed. In the meantime, the generic distinction between Anatherum and “ Andropogon ” emphasizes the long-apparent substantial divergence between (on the one hand) sect. Leptopogon and the “big bluestems.”

In transferring species to Anatherum, Vorontsova et al. (2023) relied on “species concepts based on the taxonomic compilation by POWO (2013).” Regrettably, that source is not current with recent and substantial taxonomic work in the United States that resulted in clarification and recognition (or re-recognition) of additional distinctive taxa at species rank ( Weakley & Southeastern Flora Team 2023; Bridges & Orzell 2018; Bridges & Orzell 2020; Weakley & Schori 2018; Weakley et al. 2011; Deshmukh et al. 2022). We therefore make the necessary transfers to Anatherum of these six taxa.

Anatherum campbellii (U.B. Deshmukh, M.B. Shende, & E.S. Reddy) E.L. Bridges & Orzell , comb. nov.

BASIONYM: Andropogon campbellii U.B. Deshmukh, M.B. Shende, & E.S.Reddy, Phytotaxa View in CoL 530:111. 2022. Replacement name for

Andropogon decipiens (C.S. Campbell) E.L. Bridges & Orzell (2020) View in CoL , nom. illeg., non Andropogon decipiens (Hackel) Domin,1915 View in CoL .

BASIONYM: Andropogon virginicus View in CoL L. var. decipiens Campbell, Syst. Bot 11:290. 1986. TYPE: U.S. A. FLORIDA. Martin Co.: Jonathan

Dickinson State Park , more or less open pine flatwoods, 16 Oct 1977, Campbell 3870 (HOLOTYPE: GH; ISOTYPES: DUKE, FLAS, FSU,

GA, MAINE,MISS,MISSA,TAES, TENN, USF,VDB).

See Bridges and Orzell (2020) for rationale and discussion of the recognition of this taxon.