Diphasiastrum

Diphasiastrum is a genus of clubmosses in the plant family Lycopodiaceae. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is placed in the subfamily Lycopodioideae. It is closely related to the genus Lycopodium, and some botanists treat it within a broad view of that genus as a section, Lycopodium sect. Complanata. Plants of the World Online (POWO), for example, considers Diphasiastrum to be a synonym of the genus Lycopodium. The genus was first proposed by Josef Holub in 1975, who characterized the species by their dorsiventral structure of branchlets, their chromosome number, and their special type of prothallium. Some species superficially resemble diminutive gymnosperms and have been given common names such as ground-pine or ground-cedar. Features which Holub found to be distinct in most Diphasiastrum species inclulde distinct differences between dorsal and ventral surfaces of leaves, leaves arranged in 3 parallel planes (dorsal, lateral and ventral), leaves ......read more on Wikipedia.