50 SALV1NIACEAE 



carries the sporangia on a series of short branches or lobes. (Named for Aloysins 

 Marsili, an early Italian naturalist.) 



1. M. quadrifolia L. Leaflets broadly obovate-cuneate, glabrous ; sporo- 

 carps usually 2 or 3 on a short peduncle from near the base of the petioles, 

 pediceled, glabrous or somewhat hairy, the basal teeth small, obtuse, or the 

 upper one acute. In water, the leaflets commonly floating on the surface ; 

 frequently cultivated and now somewhat extensively introduced from material 

 taken chiefly from Bantam Lake, Litchfield, Ct., where perhaps casually intro- 

 duced from Eu. 



2. M. vestita Hook. & Grev. Leaflets broadly cuneate, usually hairy, entire 

 (5-15 mm. long and broad) ; petioles 2-11 cm. long ; peduncles free from the 

 petiole, very short ; sporocarps solitary, hairy when young (about 4 mm. long), 

 with upper basal tooth longest, acute, straight or curved, lower tooth acute, the 

 sinus between them rounded. In swamps which become dry in summer j la. 

 and southwestw. 



SALVINlACEAE 



Floating plants of small size, having a more or less elongated and sometimes 

 branching axis, bearing apparently distichous leaves sporocarps (son) very soft 

 and thin-walled, two or more on a common stalk, one-celled and having a 

 central, often branched receptacle which bears either macrosporangia containing 

 solitary macrospores, or microsporangia with numerous microspores. A small 

 and interesting family of plants without close affinity to other groups. 



1. AZ6LLA Lam. 



Small moss-like plants, the stems pinnately branched, covered with minute 

 2-lobed imbricated leaves, and emitting rootlets on the under side. Sporocarps 

 in pairs beneath the stem ; the smaller ones acorn-shaped, containing at the 

 base a single macrospore with a few attached bodies of doubtful function above 

 it; the larger ones globose, and having a basal placenta which bears many 

 pedicellate microsporangia which contain masses of microspores. (Name not 

 satisfactorily explained.) 



1. A. caroliniana Willd. Plants somewhat deltoid in outline (6-25 mm. 

 broad), much branched ; leaves with ovate lobes, the lower lobe reddish, the 

 upper one green with a reddish border; macrospore with three attendant 

 corpuscles, its surface minutely granulate ; masses of microspores glochidiate. 

 Floating on quiet waters, from L. Ontario westw. and south w. Appearing like 

 a reddish hepatic moss. 



2. SALVfNIA [Mich.] Adans. 



Leaves "apparently 2-ranked, horizontally floating or subaerial, a third series 

 of foliar structures developed ventrally on the stem taking the form of fascicles of 

 root-like fibers. Sporangia subsessile, clustered, depressed-globose, longitu- 

 dinally sulcate, formed from the tips of short basal divisions of the filiform ven- 

 tral leaves. Sori basal within the fruit, the macrosporangia subsessile, the 

 microsporangia (in separate fruits) borne on filiform pedicels. (Named for 

 Prof. Antonio Maria Salvini of Florence, 1633-1729.) 



1. S. natans (L.) All. Foliage-leaves suborbicular-oblong, thickish, mostly 

 10-15 mm. long, hairy or papillose on both sides, the lower surface commonly 

 brownish or purplish. Marshes and ponds, Minn, and Mo. Long ago re- 

 ported by Pursh as "floating, like Lemna, on the surface of stagnant waters: 

 in several of the small lakes in the western parts of New York," but not 

 detected in this region by recent botanists. (Eurasia.) 



