This is widespread across southeastern and east-coastal states, but largely restricted to boggy soils in open areas, especially where disturbed by seepage, trampling, scraping or perhaps burning. The sites in CALL are artificially enhanced seeps associated with gravel quarries. The sites in eastern regions are along paths and rights-of-way. At least some of the plants in Ky. may be distinct from typical appressa, which is a more robust plant, according to J. Lasson (Athens Univ., Ohio, pers. comm.). Also, there can easily be confusion with inundata. Subfamily Lycopodielloideae (Lycopodiella, Pseudolycopodilla etc.) differs from subfamily Lycopodioideae (Diphasiastrum, Lycopodium, Dendrolycopodium, Spinulum) as follows (FNA 2, W): spores rugulate (versus reticulatre); strobili erect, nodding or pendent (versus generally erect), the peduncles if present bearing closely spaced unreduced leaves (versus remote reduced leaves); erect fertile shoots in a single dorsal rank (versus two dorsolateral ranks); leaves herbaceous, pale or yellow-green, dull, deciduous (versus rigid, bright to dark green, shiny, evergreen); principal leafy stems generally creeping (versus erect or if creeping then leaves with elongate hyaline hair tips); rhizome dying back annually to an underground vegetative tuber at apex (versus perennial, elongate, surficial or subterranean); occuring mostly in subhydric to hydroxeric sites (versus mesic to xeric).