XI. M A.RSTT i F) A-OE AE. 



Aquatic or subaquatic. Rhizome slender, creeping in the mud, pro- 

 vided with a single, central, tubular stele. Leaves without blade, or with 

 blades floating on the surface of the water or rising above it, circinate 

 in vernation. Fertile leaves or segments metamorphosed into bi- or 

 plurilocular, globose, ellipsoidal, pyriform or bean-shaped, sessile or stalked 

 sporocarps placed at the base of the petioles of the normal (barren) leaves, 

 often close to the rhizome, containing spores of 2 kinds, both macrospores 

 and microspores borne in the same sporocarp. 



Oe. AXAXS.SIL.EA., Idnni. 



Sporocarps bilateral, round, oblong, quadrate or bean-shaped, 2-valved, 

 plurilocular, horizontally veined, the locules (sori) oblong-cylindrical, hori- 

 zontally arranged in 2 close vertical rows on a mucilaginous placental 

 cord, the veins forked, with the fork-branches whether or not anastomosing, 

 the base provided with — 2 teeth. 



Rhizome wide-creeping, the leaves produced singly or in tufts from 

 its nodes. Barren leaves long-stalked, 4-foliate ; leaflets cruciate, cuneate, 

 with the outer edge truncate "or rounded, whether or not provided with 

 translucent or yellow-brown, longitudinal spurious veinlets (streaks) between 

 the true ones. — Engl. & Prantl, Nat. Pfl.Fam., P, fig. 225 A. (Marsilia). 



Tropical, subtropical, and in temperate countries. 



Arrangement of the sections. 



§ 1. EUMARSILEA. Fork branches of the veins of the sporocarps not 



anastomosing, or anastomosing near the apex only. — Engl. & 



Prantl, 1. c, flg. 225 B. 

 % 2. ZALUSIANSKAYA. Fork branches of the veins of the sporocarps 



anastomosing from the base. — Engl. & Prantl, 1. c, flg. 225 D. 



(Not in Malaya). 



