In swamps, marshes, moist woods, depressions in savannahs and prairies, on 

 stream banks and seepage slopes, and in or on the edge of lakes in e. Okla., in 

 Tex. generally distributed and common in the Timber Belt, s. and s.w. to Jefferson 

 and Victoria cos. on the Coastal Prairies, w. to Travis Co. in the Blackland 

 Prairies, adj. to the Edwards Plateau; from Nfld. to Sask., s. to Fla. and Tex.; also 

 Berm., the W. I., Mex., C. A. and S. A. 



Fam. 8. Marsileaceae R. Br. Pepperwort Family 



Plants herbaceous, rooting in mud, creeping, often partly submerged, rarely 

 floating, with slender branched rhizomes; leaves erect or floating, distichous, 

 more or less remote, filiform or with long-petiolate 2- to 4-foliolate blades; leaflets 

 (when present) of a cuneate type, with close dichotomous venation; sporocarps 

 hard, bony, globose to ellipsoid, pilose or essentially glabrous, pedunculate, one 

 to several borne on the rhizome near the base of the petiole or upon the petiole; 

 sori solitary within the compartments, each producing both megaspores and 

 microspores; megaspores germinate into prothallia that bear mostly archegonia; 

 microspores germinate into prothallia that bear antheridia. 



This family comprises three genera containing more than 70 species that are 

 found chiefly in the Old World. 



1. Leaf with distinct blade and petiole, the blade 4-foliolate 1. Marsilea 



1 . Leaves filiform, without distinct blades, the tips uncoiling as the plant matures 

 2. Pilularia 



1. Marsilea L. Water Clover 



Small plants forming dense colonies; leaves long-petiolate, with cruciform 

 (4-foliolate) blades; sporocarps subglobose to ellipsoid, mostly with 2 teeth near 

 the base, commonly provided with coarse or paleaceous hairs, splitting into 2 

 valves at maturity and emitting numerous sori on a gelatinous receptacle; sori 

 including both megasporangia and microsporangia. 



About 60 species of wide distribution, mainly in the Old World. 



The plants of some species provide shade and shelter for fish, and the sporo- 

 carps are known to be eaten by ducks. 



1. Sporocarps several on a special branch or from a common peduncle (2) 



1. Sporocarps solitary, with paleaceous hairs or naked; leaves and petioles naked 



or sparsely pubescent (3) 



2(1), Leaflets (and petioles) with long loose hairs, without colored stripes; 

 sporocarps densely covered with reddish hairs that are to 3 mm. 

 long 1. M. macropoda. 



2. Leaflets (and petioles) essentially glabrous, usually developing (with age) 



reddish-brown stripes on the lower surface; sporocarps losing (with 

 age) its light-brown hairs 2. M. mexicana. 



3(1). Leaflets flabeflate to broadly cuneate (4) 



3. Leaflets narrowly and obliquely cuneate to cuneate-oblanceolate (5) 



4(3). Rhizome without conspicuous fascicled branches; peduncle usually very 

 short, often scarcely as long as the sporocarp, usually free from 

 the petiole or attached at its very base; sporocarp with rather 

 long coarse reddish hairs 3. M. mucronata. 



4. Rhizome producing fascicled branches that are paleaceous at their tips; 



peduncle about twice the length of the sporocarp or more, usually 

 attached above the base of the petiole; sporocarp sparsely provided 

 with short coarse hairs 4. M. uncinata. 



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