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ORDER XCIIL— OPHIOGLOSSACEH. 



Perennial herbs, frequently with a tuberous root producing 1 or 

 more fronds with straight (not circinate) vernation. Frond com- 

 monly with 2 branches, the lower sterile, the upper fertile ; very 

 rarely the fertile frond is separate from the barren one, though some 

 species produce accessory sterile fronds, or sterile fronds only on 

 young and weak plants. Sporangia in simple or compound spikes, 

 naked, coriaceous, without any thickened ring, 2-valved, opening by 

 a transverse slit, rarely by a vertical slit. Spores all similar, 

 very minute. Prothallium subterranean, destitute of chlorophyll, 

 tuberiform. 



The sporangia in Ophioglossaceae are produced by a metamor- 

 phosis of the leaf itself, not from a single epidermal cell, as in 

 Filices, from which these plants differ also in their straight vernation 

 and subterranean prothallium destitute of chlorophyll. 



GENUS L—O PHIOGLOSSUM. Linn. 



Herbs with a short fleshy tuberiform caudex, praemorse below. 

 New frond produced exterior to the base of the stalk of that of the 

 preceding year. Barren branch of the frond entire, more rarely 

 forked or palmate ; fertile branch stalked, undivided. Sporangia 

 connate, disposed in a stalked 2-ranked simple linear flattened spike. 



Xame from oc£is (opits), serpent, and yAwcrcra (jjlossa), tongue. 



SPECIES I.-OPHIOGLOSSUM VULGATUM. Linn. 



Plate 1835. 

 Rabenh. Crypt. Vase. Europ. Exsicc. No. 7. 



Caudex oblong-cylindrical, very slightly swollen. Fronds usually 

 solitary. Barren segment or frond ovate or oval or elliptical, rarely 

 oblanceolate-elliptical,not greatly attenuated at the base, entire, rather 

 thick, fleshy ; veins conspicuous in the dried plant when held against 

 the light, anastomosing and forming rather elongate areolae at the 

 base and centre of the frond, and short roundish-polygonal ones at 

 the margin ; primary areola? containing secondary ones ; cells of the 

 epidermis flexuose-sided. Spike stalked, strapshaped-linear, com- 

 pressed, apiculate ; stalk cylindrical. Spores tubercled. 



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