FLORA. 



Subkingdom PTERIDOPHYTA. 



Ferns and Fern-Allies.* 



Plants containing woody and vascular tissues producing spores asex- 

 ually, which, on germination, develop small flat mostly green prothallia 

 (gametophyte). On these are borne the reproductive organs, the female 

 known as archegones, the male as antherids. From the fertilization of the 

 egg in the archegone by spermatozoids produced in the antherid, the 

 asexual phase (sporophyte) of the plant is developed ; this phase is rep- 

 resented by an ordinary fern, lycopod or horsetail. Comprising about 

 4000 living species, of which more than three-fourths are confined to 

 tropical regions. 



Order I. FILICALES. 



Spores, all of one kind and size, produced in sporanges, which are 

 borne on the back of a leaf, in spikes or panicles. 

 Vernation erect, or inclined ; sporanges in spikes, or panicles, opening by a transverse 



slit. Fam. i. Ophioglossacece. 



Vernation coiled ; sporanges reticulated, usually provided with a ring (annulus). 

 Sporanges opening vertically. 



Sporanges panicled, with a rudimentary ring ; marsh ferns. 



Fam. 2. Osmundacea. 

 Sporanges sessile on a filiform receptacle : leaves filmy, translucent. 



Fam. 3. Hymenophyllacea. 

 Sporanges ovoid, in panicles, or spikes, with a vertical ring. 



Fam. 4, Schiz<zace&. 



Sporanges opening transversely, provided with a vertical ring, borne in sori on the 

 back or margin of a leaf. Fam. 5. Polypodiacece. 



Family i. OPHIOGLOSSACE^E Presl. 

 Adder's- Tongue Family. 



More or less succulent plants consisting of a stem and leaf growing 

 from a fleshy root. Sporophyll in the form of a spike or panicle, the 

 sporanges formed from the interior tissues, naked, opening at maturity 

 by a transverse slit. Spores yellow. Prothalli subterranean, devoid of 

 chlorophyll. Contains five genera, three of which are American. 



Veins reticulate ; sporanges cohering in a distichous spike. i. Ophioglossum. 



Veins free ; sporanges distinct, borne in spikes or panicles. 2. Botrychium. 



i. OPHIOGLOSSUM L. 



Low plants from a small fleshy rootstock, with slender fleshy roots, the bud for 

 the following year formed at the side of the base of the stem. Leaves simple, soli- 

 tary, borne on the stem. Sporophyll terminal, formed of two rows of large coales- 



* Contributed by Professor LUCIEN M. UNDERWOOD. 



