14: 



Fructification considting of two sorts enclosed in capsular re- 

 ceptacles which are borne on peduncles which rise from the rhi- 

 zome near the leaf-stalk or else more or less connected with the 

 latter. The receptacles 2—4 valved and emit a gummy sub- 

 stance containing micro- and macro-spores mixed or else a mucous 

 cjlinder bearing at, intervals oblong sporangia containing the 

 two kinds of spores ; each on opposite sides. 



•MARSILIA L. 



Aquatic or in partially dried up marshes, rootstocks creeping, 

 frequently sending up elongated petioles which bear at the sum- 

 mit a whorl of four uervose-veined leaflets. 



M. v:fisiTATA Hook and Grev. Leaflets broadly cuneate, 

 usually hairy, entire, petioles 1—4 inches long, peduncles free 

 from the petiole, sporncarps solitary, short-peduncled, very 

 hairy when young. In swamps which dry up in summer ; Iowa 

 and southwtstward. From Gray's Manual. 



Order 7. S A L V1NIACE.E . 



Diminutive floating plants with a more or less elongated and . 

 sometimes branching axis, hearing Hpparent'y -small leaves ar- 

 ranged in two vertical ranks ; sporocarps soft, thin walled, one 

 celled, and having a central, often branched receptacle which 

 bears either macm-sporangia containing solitary macrospores or 

 microsporangia with numerous microspores. 



AZOLLA LAM. 



Small, moss-like in aspect ; sterna pinnately branched ; leaves 

 miniite, two-lobcd, imbricated, emitting rootlets from the under- 

 side; sporocarps in two pairs beneath the stem, axillary, un- 

 equal, the smaller acorn shaped containing a basal macro- 

 spore, the larger speroida', containing a basal placentae bearing 

 many pedicellate micro-sporangia which contain masses of mi- 

 crospore's. 



• A. CAROLTNiANA WiLLD. Plants deltoid in outline, much 

 branched, one-quarter to an inch in width ; leaves with minute 

 ovate lobes, the upper green with a reddish border, the lower 

 red. This plant occurs in large masses floating in still water. 

 The color of the leaf-lobes imparts to the mass a characteristic 

 reddish hue. Found in Muscatine slough. Mr. Reppert. 



