Leaves in 4 ranks along the stems, the margins minutely serrulate. Lateral
leaves in 2 ranks along the branches, 1.3–2.3 mm long, spreading, ovate. Leaves
of the upper stem surface in 2 ranks, 1–1.6 mm long, appressed, ovate, the tip
acute to slightly attenuate, the midvein not extending to the tip. Strobili
somewhat flattened in cross-section, the leaves 4-ranked, the megasporangia
usually occurring in the rank on the underside of the strobilus. Megaspores
light yellow, with a dense network of ridges on the surface. Microspores
orange. 2n=18. May–November.
Scattered in the southern half of the state west to Camden
and Ozark Counties (eastern U.S west to Texas). On moist soil
and rocks along creek banks and bluff ledges.
This species and S. eclipes are very closely related and can be
difficult to distinguish. Leaf shape varies with leaf position on the plant as
well as apparently with soil acidity (Buck, 1977). The relationship and
taxonomic distinctions between these two spikemosses requires further study.