Much like no. 13 [Lycopodium stitchense Rupr.], but the lvs of the ultimate vegetative branchlets strictly 4-ranked, decussately opposite, subtrimorphic; every other pair of lvs conspicuously decurrent on the stem as a pair of flanges, the flange continuous with one margin of the lf, so that the stem appears somewhat flattened or wing-margined with the lvs of the lateral rows twisted; free tips of these lateral lvs mostly 1.5-2 mm; dorsal and ventral lvs distinctly different from the lateral ones and also different inter se, those of the upper side subulate, straight, loosely appressed or closely ascending, 2-3 mm, shortly decurrent, those of the lower side (which appears to be concave because of the way the lateral lvs are twisted) tending to have a short, stout, ascending-spreading subpetiolar base (this often laterally compressed) and an erect (parallel to the stem) or incurved blade 2-3 mm and lanceolate or lance-ovate; 2n=46. Cold woods and subalpine meadows and rocky slopes; circumboreal, s. to Keweenaw Co., Mich. and the Gasp顰enins. of Que.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.