Flora 



OF 



Jackson County, Missouri. 



Subkingdom PTERIDOPHYTA. 



Spore-bearing plants containing wood}' tissue. Spore on germination 

 forming a flat green body (prothallus), on which are borne the sexual 

 organs, the antherids producing spermatozoids, and the archegones. 

 oospheres. From the fertilization of the latter by the former the spore 

 bearing stage is developed. 



Family 1. OPHIOGLOSSACEAE Presl. 

 Sterile and fertile portions of frond dissimilar, erect in vernation. 

 Sporangia in spikes or panicles, opening by a transverse slit. Spores 

 numerous. 



Sterile portion of frond entire. 1. OPHIOGLOSSUM. 



Sterile portion of frond divided. 2. Botrychium. 



1. OPHIOGLOSSUM L. 



Low plants from fleshy rootstocks. Sporangia coherent in two ranks 

 on edge of simple spike-like fertile portion of frond. Sterile portion 

 leaf-like, with numerous anastomosing veinlets. 



1. O. Engelmanni Prantl. Adder's-tongue. Rootstock deep- 

 seated : sterile segment ovate to elliptic-oblong, mucronate, 2^-3'' long : 

 fertile segment about 1^ long, borne on a stalk 2^-V long. — In large colo- 

 nies in thin soil on limestone ledges throughout the southern portion. 

 June, July. 



2. BOTRYCHIUM Sw. 



Fertile portion of frond panicled. Sporangia separate and distinct. 

 Sterile portion much divided, feru-like. 



Sterile frond thin ; the ultimate segments cut-toothed 



at apex. 1. B. Virginianum. 



Sterile frond thick ; the ultimate segments denticu- 

 late. 2. B. obHqmim. 



1. B. Virginianum (L. ) Sw. Rattle-snake Fern. Fronds 6''-3° 

 high : sterile segment sessile, borne above the middle of the plant, tri- 

 angular in outline, ternate, with divisions once to twice pinnatifid. — 

 Rather frequent in rich woods throughout. May, June. 

 1 1 



