296 Proceedings of the Ohio State Academy of Science. 



Order, Salviniales. 



Small floating plants with small leaves with globose sporo- 

 carps containing the megasporangia and microsporangia. 



Salviniaceae. Salvinia Family. 



Besides the native species below Salvinia natans (L.) Hoffm. 

 is often kept in green houses and conservatories. 



22. Azolla Lam. 



I. Azolla caroliniana Willd. Carolina Azolla. 



Small greenish or reddish plants, deltoid or triangular-ovate 

 in outline, pinnately branching, and free-floating, with minute 

 two-lobed, imbricated leaves and delicate rootlets. Sporocarps 

 of two kinds, the smaller ovoid containing a single megaspore, 

 the larger globose, producing many stalked microsporangia, 

 which contain several peculiar spore-containing masses beset 

 with arrow-like processes. Sometimes covering large surfaces 

 of water. Hamilton, Lucas, and Lake counties. 



Order, Marsileales. 



Herbaceous perennials with slender creeping rhizomes and 

 four-foliate or filiform leaves. Sporocarps borne on the petioles, 

 containing both megasporangia and microsporangia. 



Marsilcaccac. Marsilea Family. 



Water-ferns with four-foliate leaves on slender petioles ; 

 leaflets turning with the light. 



23. Marsi'lea L. 



I. Marsilea quadrifolia L. European Marsilea. 



Occasionally cultivated and found as a waif in Franklin 

 county. 



