Selaginella antioquensis (Selaginellaceae–Lycopodiophyta), a remarkable new species from Antioquia, Colombia, and the first report of S. simplex in the country

Selaginella antioquensisis described as a new species so far known to occur only in the Central Andean Cordillera in the municipalities of Amalfi and Anorí, Department of Antioquia, Colombia. It is characterized by its creeping to decumbent habit with flattened stems and branches, the main stems 1- or 2-branched, the lateral leaf oblong with long-ciliate basiscopic margins along the proximal \(\frac1{16}\) $\frac{1}{16}$  and obtuse to obtuse-truncate or subacute apices. Its overall growth habit, the stem and branch form, and the shape, position, and arrangement of the lateral leaves give a centipediform aspect to the plant. It is further distinguished by its median leaves that are broadly-elliptic to broadly ovate-elliptic with the outer base bearing a tuft of long cilia, long-aristate apices, each \(\frac13\) $\frac{1}{3}$  – \(\frac12\) $\frac{1}{2}$  the length of the lamina, and lateral and sessile strobili. This species is a member of the “Selaginella cruciformis group”, which we define here. We discuss the unique morphological characteristics of S. antioquensis and compare it to morphologically similar taxa, and provide a conservation assessment for it. This study also led us to report a widespread Neotropical species, S. simplex, as a new record for Colombia. Finally, illustrations and a distribution map are included for the two species here newly reported in Colombia: S. antioquensis and S. simplex.