GENUS I. 



CLUB-MOSS FAMILY. 



43 



Four genera and about no species. Besides the following, Psilotum occurs in Florida, the 

 two other genera only in Australia. 



i. LYCOPODIUM L. Sp. PL noo. 1753. 



Perennial plants with evergreen i-nerved leaves arranged in 4-16 ranks. Sporanges 

 coriaceous, flattened, reniform, i-celled, situated in the axils of ordinary leaves or in those 

 of the upper modified, bract-like ones, which are imbricated in sessile or peduncled spikes, 

 opening transversely into 2 valves, usually by a line around the margin. Spores all of one 

 kind, copious, sulphur-yellow, readily inflammable from the abundant oil they contain. 

 [Greek, meaning wolf's-foot, perhaps in allusion to the branching roots of some species.] 



About 100 species of wide geographic distribution, the largest occurring in the Andes of South 

 America and in the Himalayas. Type species : Lycopodium clavatum L. 



Sporophyls not closely associated in terminal spikes. 



Stems rigidly erect ; leaves ascending, nearly uniform. i. L. Selago. 



Stems ascending ; leaves spreading or deflexed, longer or shorter in alternating zones. 

 Leaves distinctly broadest above the middle, there usually erose-denticulate. 



2. L. htcidulum. 



Leaves linear or nearly so, entire or minutely denticulate. 3. L. porophilum. 



Sporophyls closely associated in terminal spikes. 



Sporophyls similar to the foliar leaves in form and texture ; Sporanges subglobose. 



Sporophyls linear-deltoid, mostly entire ; plants small. 4. L. inundatum. 



Sporophyls linear to lanceolate from a broader base ; plants larger. 



Peduncles slender, the leaves incurved and mostly appressed ; spikes slender, the sporo- 



phyls less than 3" long, abruptly subulate, incurved. 5. L. adpressum. 



Peduncles very svout, the leaves more numerous and close, mostly ascending, not in- 

 curved ; spikes stout, the sporophyls more than 4" long, attenuate, ascending, spreading 

 or reflexed. 6. L. alopecuroides. 



Sporophyls bract-like, very unlike the foliar leaves ; sporanges reniform. 



Stems with numerous erect or assurgent leafy aerial branches, the spikes terminal upon 



some of these. 

 Leaves of the ultimate aerial branches in 5 or more rows. 



Main stem creeping deep in the ground ; aerial branches few, tree-like. 



7. L. obscurum. 

 Main stem prostrate, or (in no. 10) a little below the surface ; aerial branches 



numerous, not tree-like. 



Leaves of the ultimate aerial branches in 5 rows. to. L. sitchense. 



Leaves of the ultimate aerial branches in more than 5 rows. 



Spikes solitary, sessile. 8. L. annotinum. 



Spikes one or several, on elongate peduncles. 12. L. clavatum. 



Leaves of the ultimate aerial branches in 4 rows. 



Spikes sessile upon leafy branches. 9. L. alpinum. 



Spikes borne upon bracteate peduncles, these terminal upon leafy branches. 



Leaves of the ultimate aerial branches adnate considerably more than half their 



length. 



Ultimate aerial branches conspicuously flattened ; leaves of the under row 



greatly reduced, minute, deltoid-cuspidate. 14. L. complanatum. 



Ultimate aerial branches narrower and less flattened ; leaves of the under row 



scarcely reduced, acicular. 15. L. tristachyum. 



Leaves of the ultimate aerial branches adnate about half their length or less. 



n. L. sabinaefolium. 



Stems without leafy aerial branches, the elongate peduncles arising directly from the 

 prostrate stem. 13. L. carolinianum. 



i. Lycopodium Selago L. Fir Club-moss. 

 Fig. 100. 



Lycopodium Selago L. Sp. PI. 1102. 1753. 



Stems rigidly erect from a short slender curved 

 base, several times dichotomous, the densely folia- 

 ceous vertical branches forming mostly compact 

 level-topped tufts 2'-6' high ; leaves nearly or quite 

 uniform, very numerous, crowded, more or less 

 appressed, or at least ascending, narrowly deltoid- 

 lanceolate or somewhat acicular from a broader base, 

 shining, pale green or yellowish, usually entire, acute, 

 those bearing the sporanges (below the summit) a 

 little shorter but not differing otherwise; plant fre- 

 quently gemmiparous in the axils of the upper leaves. 



On rocks, Labrador and Greenland to Alaska, south 

 to the mountains of Maine, New Hampshire, Vermont 

 and northern New York, on the summits of the higher 

 Alleghenies to North Carolina, and to Michigan and 

 Washington. Also in Europe and Asia. Autumn. 

 Upright Club-moss. Fir-moss, Tree-moss, Fox-feet. 



