Perennial fern ally 12 - 15 cm tall Leaves: in no particular arrangement, just closely spaced, stalkless, yellow-green to green, lustrous, with some very low bumps, non-toothed or few large teeth near base, stomates present on both surfaces, but less so on the lower surface. The leaf position and shape differ along the stem with those at the stem base being reflexed and the rest spreading, except those at the tip are ascending and form a cluster. Largest leaves 5 - 8 mm long and lance-shaped with almost parallel sides, but smallest leaves only 3 - 6 mm long, triangular (widest at base), and situated near annual constrictions of the stem. Spores: hundreds per sac, all of one kind, 29 - 38 microns diameter, thick-walled, three-sectioned (trilete) with abruptly blunt angles and pits or shallow grooves. The spores give rise to the gametophyte (the sexual phase of the plant), which is small, narrow or elliptical, underground, not green, but saprophytic, and inhabited by symbiotic fungi (mycorrhizae). Stems: erect, clustered, greenish, 2 - 16 mm in diameter, possibly becoming a bit decumbent, but strictly horizontal stems never produced.
Similar species: Huperzia porophila could probably be easily confused with our more common species H. lucidula, but that species differs by having darker green, obviously toothed and wider leaves which are widest at or above their middles.
Habitat and ecology: Incredibly rare, likely extinct from the Chicago Region, if it was ever present. The species has very strict habitat requirements of damp, shaded, acidic sandstone. The only report of the species is quite old (late 1800's) and no voucher specimen can be found. Its distribution is primarily south of the Chicago Region and includes a far-separated (disjunct) area to the northwest in the Driftless Area of Wisconsin, Minnesota, and Iowa.
Occurence in the Chicago region: native-
Notes: The occurrence of this species in the Chicago Region is questionable, but certainly it appears to have been in a very unique location if it ever was present. The current distribution of this species is quite distant from the Chicago Region. It is known to hybridize with H. lucidula to produce a sterile hybrid named H. x bartleyi.
Etymology: Huperzia is named after Johann Peter Huperz, an early 19th century German botanist and fern specialist. Porophila is Latin meaning "lover of soft stone", in reference to its preferred habitat on sandstone.
Much like L. selago var. selago, but with looser, shortly creeping base and with slight, inconspicuous zonation of longer and shorter lvs (approaching but not matching no. 3 [Lycopodium lucidulum Michx.] in both of these regards); lvs spreading, mostly 5-8 נ0.8-1.2 mm, broadest near the middle and slightly toothed above; high polyploid. Acid, rocky (usually sandstone) cliffs and ledges; Pa. to Minn., s. to N.C., Ala., and Mo.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.