Generic division in the lycophytes
Vascular plant curators here are probably already aware that there's a significant variance between the classification for ferns adopted by POWO, and PPG I; the latter (in my opinion, anyway) has more support among the pteridological community and we've adopted it as our classification scheme. (Hopefully this summer I'll have time to get back to adding deviations to harmonize the two.)
However, a similar problem exists with regards to lycophytes, specifically family Lycopodiaceae. Older systems treat this family as monogeneric, containing only genus Lycopodium. More recently, the deeper divisions in the family have been recognized and Lycopodium sensu latissimo has been split up; the question is, how much to do so.
PPG I recognizes 16 genera in Lycopodiaceae, divided among three subfamilies: the Huperzioideae, Lycopodielloideae, and Lycopodioideae. By contrast, POWO treats each of those subfamilies as the broadly circumscribed genera Huperzia, Lycopodiella, and Lycopodium, respectively.
Our existing taxonomy, owing in part to its roots in Flora Novae-Angliae, generally inclines towards the "splittier" approach taken by PPG I. My personal sense of taxonomic trends is that the degree of splitting in PPG I, which was pretty forward when Haines wrote it into Flora Novae-Angliae, has now become pretty widely accepted and that we should adopt PPG I for lycophytes as well as ferns.
The main impact would probably be in the tropics, where Pseudolycopodiella and Palhinhaea would get split from Lycopodiella, a bunch of Huperzia would get moved over to Phlegmariurus (which is active in our taxonomy, but many species have not been moved). The Palhinhaea split would probably be the most visible, as Palhinhaea/Lycopodiella cernua is an extremely common pan-tropical clubmoss.
I'd like to know if other curators are on board with this approach; @crothfels who has brought up some of the inconsistencies in our current taxonomy.
