MARSILEACEM. 1^5 



ORDER II. MARSILEACE^ R. Br. 



Perennial plants rooted in mud, with a slender creeping 

 rootstock and either filiform or 4-parted, long-petioled leaves. 

 Fructification consisting of sporocarps borne on peduncles, 

 which rise from the rootstock near the leaf-stalk or consolidated 

 with it and containing both macrosporesand microspores. Con- 

 sistino- of two genera both found in this country. 



I. Marsilea L. Sporocarps ovoid ; leaves quadrifoliate. 



II. Pilularia L. Sporocarps globose ; leaves filiform. 



I. MARSILEA L. 



Sporocarps ovoid or bean-shaped, composed of two vertical 

 valves liaving several transverse compartments or sori in each 

 valve, the sori composed of both macrosporangia and micro- 

 sporangia. Sporocarps also provided with a ring which at the 

 opening of the valves swells and tears the sori from tlieir posi- 

 tion. Leaves quadrifoliate on slender petioles ; the sporocarps 

 peduncled and rising from the petiole or from the rootstock at 

 the base of the petiole. Named for Aloysius Marsili, an early 

 Italian naturalist. Contains about 40 species, four occurring 

 within our limits. 



* Sporocarps 2 — 6 o/i each peduncle. 



1. M. quadrifolia L. Plant usually slender, 5 — 12 cm. 

 high; leaflets variable, 4 — 14 mm. wide, 5 — 15 mm. long, mar- 

 gins entire, smooth, or rarely with scattered hairs when young; 

 sporocarps 2 (rarely 3) on a branching peduncle, which is usu- 

 ally attached to the stipe near its base, but sometimes as much 

 as 2 cm. above ; young sporocarp with short yellowish-brown 

 hairs, later becoming naked and dark purple; lower tooth ob- 

 tuse, upper small, acute or obtuse; sori, 8 org in each valve. 

 Bantam Lake, Litchfield County, Connecticut {Dr. T. F. Allen), 

 from whence it has been cultivated in several localities. 



2. M. macropoda Engelm. Plant robust, 10 — 25 cm. 

 high ; leaflets large, 2 — 5 cm. long, 2 cm. wide or less, usually 

 undulate, clothed with white hairs on both sides when young, 

 becoming smoother with age ; sporocarps 2 — 6. on erect brandl- 

 ing peduncles, ascending, densely villose, 6 — 8 mm. long, 5-6 

 mm. wide ; raphe short, the louder tooth obtuse, the upper in- 



