274 FERNS : BRITISH AND FOREIGN. 



pound, rarely pinnate. Veins forked; venules free. Fertile 

 segments rachiform, compound paniculate. Sporangia distinct, 

 in two unilateral rows, opening vertically in two equal valves. 



1. B. simplex, Hitchcock ; Hook, et Grev. Ic. Fil. t. 82. 



North America. 



2. B. Lunaria, 8w. ; Schk. Fil 1. 154 ; Hook. Gen. Fil. t. 47 A ; 



Lindl. and Moore's Brit. Ferns, t. 51 A; Hook. Brit. 

 Ferns, t. 48 ; Sowerby's Ferns, t. 45. Osmunda 

 Lunaria, Linn. Eng. Bot. t. 318; /3 rutaceum. 

 Botrychium rutaceum, Siv. ; Schk. Fil. t. 155 B. 

 Temperate Zone of the Northern Hemisphere. 



3. B. lunar ioides, Sw. Botrypus lunarioides, Miclix.; 



ft obliquum, A. Gray. Botrychium obliquum, Muhl. 

 B. lunarioides, Schk. Fil. t. 157 ; y dissectum, 

 A. Gray. Botrychium dissectum, Spr. ; Schk. Fil. 

 1. 158. North America. 



4. B. Virginicum, Willd. Osmunda Yirginica, Linn. Botry- 



chium Virginian um, Sw.; Schk. Fil. t. 156; Hook. 

 Gard. Ferns, t. 29. Temperate Zone of the Northern 

 Hemisphere, Tropical America, East Indies, and 

 Ceylon. 



ORDER IY. LYCOPODIACE^I. 



Flowerless moss or fern-like plants, consisting of firm, erect, 

 creeping or pendulous, simple or branched, often flagelliform 

 stems, furnished with acerose, rusciform or jungermannia-like, 

 sessile leaves, which are generally imbricate, and often disti- 

 chous and of two kinds, bearing in their axis, or on contracted 

 terminal spikes, 1-3-celled reniform or globose sessile spore- 

 cases (sporangia), of one or of two forms ; one called Antheri- 

 dangia, containing numerous spores ; the other Oophoridangia, 

 containing 1-3-8 large spores. 



158. PSILOTUM, Sw. 



Stems dichotomously forked, compressed or angular, rigid, 

 erect or slender, pendulous ; leaves obsolete or small, bract- 



