LYCOPODIACE^E. (CLUB-MOSS FAMILY.) 695 



2. OSMUNDOPTERIS. Base of the stalk containing the bud open along one 

 side; sterile segment membranaceous ; the cells of the epidermis ftexuous. 



6. B. Virginianum, Swartz. Fronds tall and ample; sterile segment 

 sessile above the middle of the plant, broadly triangular, thin and membrana- 

 ceous, ternate ; the short-stalked primary divisions once or twice pinnate, and 

 then once or twice pinnatifid ; the oblong lobes cut-toothed toward the apex ; 

 veins forking from a midvein ; fertile part 2-3-pinnate. Rich woods; com- 

 mon. Plant 1-2 high, or often reduced to a few inches, in which case it is 

 B. gracile, Pursh, June, July. (Eu.) 



2. OPHIOGLOSSUM, L. ADDER'S-TONGUE. (PI. 20.) 



Rootstock erect, fleshy and sometimes tuberous, with slender fleshy roots 

 which are sometimes proliferous ; bud placed by the side of the base of the 

 stalk; fronds with auterior and posterior segments as in Botrychium, but 

 the coriaceous sporangia connate and coherent in two ranks on the edges 

 of a simple spike. Sterile segment fleshy, simple in our species ; the veins 

 reticulated. Spores copious, sulphur-yellow. (Name from o<pis, a serpent, and 

 y\w(r(ra, tongue.) 



1. O. VUlgatum, L. Fronds from a slender rootstock (2-12' high), 

 mostly solitary ; sterile segment sessile near the middle of the plant, ovate or 

 elliptical (1 -3' long) ; midvein indistinct or none ; veins forming small meshes 

 enclosed in larger ones. Bogs and pastures; not common. July. (Eu.) 



ORDER 133. LYCOPODIACE^E. ( CLUB-MOSS FAMILY.) 



Low plants, usually of moss-like aspect, with elongated and often much 

 branched stems covered with small lanceolate or subulate, rarely oblong 

 or rounded, persistent entire leaves ; the sporangia 1 - 3-celled, solitary 

 in the axils of the leaves, or on their upper surface, when ripe opening 

 into two or three valves, and shedding the numerous yellow spores, which 

 are all of one kind. The Order, as here defined, consists mainly of the 

 large genus 



1. LYCOPODIUM, L. CLUB-MOSS. (PI. 21.) 



Spore-cases coriaceous, flattened, usually kidney-shaped, 1-celled, 2-valved, 

 mostly by a transverse line round the margin, discharging the subtile spores in 

 the form of a copious sulphur-colored inflammable powder. Perennials, with 

 evergreen one-nerved leaves, imbricated or crowded in 4-16 ranks. (Xame 

 compounded of \VKOS, a wolf, and irovs,foot, from no obvious resemblance.) 



1. Spore-cases in the axils of the ordinary (dark green and shining, rigid, 

 lanceolate, about 8-ranked) leaves. 



1. L. SelagO, L. Stems erect and rigid, dichotomous, forming a level- 

 topped cluster (3 - 6' high) ; leaves uniform, crowded, ascending, glossy, pointed, 

 entire or denticulate ; sporangia in the axils of unaltered leaves. Mountain- 

 tops, Maine to Lake Superior, and northward. The leaves of this and the next 

 species often bear little gemmre, with the lower bracts pointed, and the 2-3 

 uppermost broadly obovate and fleshy, as figured in 1768 by Dillenius. These 

 gemma; fall to the ground and their axis grows into the stem of a new plant, 



