Name honors Count Luigi Ferdinanda Marsigli (1656-1730), Italian botanist at Bologna.

Plants small, terrestrial, of transient pools. Rhizomes slender, long-creeping. Fronds clustered, narrow. Stipes round, green. Blades 4-leaf-cloverlike, with 4 closely attached pinnae at tips of stipes. Sporocarps elliptic, firm, hairy (glabrous with age), single or multiple with firm, thick walls, peduncles inserted on bases of petioles or on rhizomes near petiole bases, each sporocarp containing a sorophore bearing multiple sori containing megaspores or microspores. The sporocarps are probably derived from highly modified blades fused at the margins to form the capsules. Stalks are probably derived from stipes. The sporocarps and enclosed sorophores containing macrospores and micros pores are extremely drought resistant and may remain dry and dormant for many decades, reviving when rains return.

A widespread genus of fifty to seventy species, absent only from very cold climates. The species are often difficult to distinguish because of the similar morphology of often sterile plants. Represented in Hawai 'i by a single endemic species.

Marsilea crenata C. Pres!, from Southeast Asia and the Philippines, has recently been noticed as established in a small area around demonstration taro patches in Makiki Val~ey.·