A genus of about 15-20 species, mostly north temperate amd subarctic.

1. Foliage dark green, not glaucous; horizontal branchlets 2-4 mm wide (including the leaves); branchlets without conspicuous annual constrictions; rhizomes 0-1 cm deep (which can be determined by pulling up a single upright shoot -- the depth to rhizome is approximately the length of the whitwe portion of the vertical stem); abaxial rank of leaves shorter than lateral ranks (thus the branchlets flat in cross-section)......D. digitatum

1. Foliage blue-green, glaucous; horizontal branchlets 1-2 mm wide (including the leaves); branchlets with conspicuous annual constrictions; rhizomes (1-) 5-12 cm deep; abaxial rank of leaves as long as lateral ranks (thus the branchlets more-or-less square in cross-section)......D. tristachyum

Diphasiastrum tristachyum (Pursh) Holub, Blue Ground-cedar. Mt (NC, SC, VA), Pd (NC, VA), Cp (VA): dry forests, glades, barrens, forest openings; uncommon, rare in Piedmont and Coastal Plain (SC Rare List). July-September. Widespread in ne. North America, south in the mountains to SC, GA, and Al. [= FNA; Lycopodium tristachyum Pursh -- RAB, C, F, G, K, S, W]

D. Hhabereri (House) Holub [D. digitatum H tristachyum; Lycopodium H habereri House] is known from widely scattered localities in our area.

D. Hsabinifolium (Willdenow) Holub [D. sitchense (Ruprecht) Holub H tristachyum] ranges south to e. PA, where believed extirpated.

A genus of about 10-15 species, north temperate and arctic (and tropical mountains of Asia).

Several hybrids are known from our area; they usually occur in intermediate habitats (such as in thin soil at the base of cliffs) and generally are found in proximity to both parents, but sometimes occur in the absence of one or both parents. Hybrids can be recognized by their intermediate morphology. The hybrid H. appalachiana H lucidula may be expected at cliff bases on high elevation rocky summits. It is known from Chimney Rock Park, Rutherford County (the lowest elevation occurrence of H. appalachiana in NC) and from Roan Mountain, Mitchell County, and Grandfather Mountain, Avery County. The hybrid H. lucidula H porophila [H. Hbartleyi (Cusick) Kartesz & Gandhi] is reported for NC by Waterway (1986). Both of these hybrids can be told from their parents by the presence of stomates on both surfaces of the leaf (unlike H. lucidula), but their marked lower density on the upper surface (unlike H. appalachiana or H. porophila).

A genus of about 15-20 species, temperate and tropical.

1. Leaves of prostrate stems entire to sparsely ciliate-toothed; surface of the erect stems visible, not hidden by the leaves......2

1. Leaves of prostrate stems conspicuously ciliate-toothed; surface of the erect stems hidden by the leaves......3

All pairwise combinations of sympatric species form fertile hybrids (only L. inundata and L. prostrata are entirely allopatric and not known to hybridize). The following hybrids should be expected where the parents grow together. Which occur in our area is uncertain at present. L. alopecuroides H appressa [L. Hcopelandii (Eig.) Cranfill] L. alopecuroides H inundata L. alopecuroides H prostrata [L. Hbrucei Cranfill] L. appressa H inundata L. appressa H prostrata

Additional research on this genus in our area is needed. Two fertile tetraploid species were recently named from MI (Bruce, Wagner, & Beitel 1991), and additional cryptic or semicryptic species may be found in the Southeastern Coastal Plain.

Species of this genus are difficult to identify. They often grow together; it is not uncommon to find two or more species at a single site in the Coastal Plain. Juvenile plants, resprouting in spring or after fire are especially difficult. In contrast to the other species, Pseudolycopodiella caroliniana and, to a lesser degree, L. prostrata, are dorsiventrally flattened (or apparently distichous), but it seems that juvenile sprouts of all species are somewhat flattened.

References: Wagner, Beitel, & Moran (1989); Hickey (1977).

A genus of 15-25 species, mainly temperate and subarctic.

1. Erect leafy stems 10 mm or more in diameter (including the leaves), not treelike or fanlike......2

1. Erect leafy stems 3-8 mm in diameter (including the leaves), treelike or fanlike......3

L. lagopus (Laestadius ex C. Hartman) G. Zinserling ex Kuzeneva-Prochorova [= L. clavatum Linnaeus var. monostachyon Greville & Hooker] ranges south to c. PA.

A genus of 10-15 species, tropical and subtropical.

Palhinhaea cernua (Linnaeus) Vasconcellos & Franco, Nodding Clubmoss, Staghorn Clubmoss. Cp (SC): disturbed moist areas; rare, perhaps adventive from further south this species is pantropical, occurring in the both the Neotropics and the Paleotropics. Its occurrence in our area may be adventive. [= FNA; Lycopodiella cernua (Linnaeus) Pichi Sermolli var. cernua -- K; Lycopodium cernuum Linnaeus -- S]

A genus of about 12 species, subcosmopolitan.

Pseudolycopodiella carolinian (Linnaeus) Holub, Carolina Bog Clubmoss, Slender Clubmoss. Cp (NC, SC, VA): savannas, seepages; uncommon, rare in VA (VA Rare List). July-September. This species occurs in se. North America, the West Indies, and is widespread in the Southern Hemisphere. In North America, it ranges from MA south to FL and west to e. TX. It is often placed in a separate and monotypic section, and warrants status as a genus separate from Lycopodiella. In addition to the morphologic distinctions, this species has considerable anatomical differences, a different base chromosome number than the four species of Lycopodiella (x = 35 vs. x = 78), and does not hybridize with Lycopodiella (Wagner & Beitel 1992). [= FNA; Lycopodium carolinianum Linnaeus -- RAB, C, F, G, S; Lycopodiella caroliniana (Linnaeus) Pichi Sermolli var. caroliniana -- K]

The division of North American Lycopodium into three or more genera has been strongly advocated by Wagner & Beitel (1992) and numerous other recent authors. The traditionally broad Lycopodium appears to include a number of natural groups which are strikingly different from one another and have likely constituted separate lineages for many millions of years. These natural groups are separable by numerous morphological, developmental, and anatomical characters, karyotype, and inability to hybridize. Wagner & Beitel divide Lycopodium of our area into six genera in three subfamilies, as follows: Huperzia in Subfamily Huperzioideae, Lycopodium and Diphasiastrum in Subfamily Lycopodioideae, and Lycopodiella, Palhinhaea, and Pseudolycopodiella in Subfamily Lycopodielloideae. The reasoning behind this division is very strong, and it is here followed. Profound diferences in anatomy, morphology, reproduction, gametophyte morphology, and karyotype support this separation. The chromosome numbers of our genera: Diphasiastrum (x=23), Huperzia (x=67, 68), Lycopodiella (x=78), Lycopodium (x=34), Palhinhaea (x=55), Pseudolycopodiella (x=35).