Family

Marsileaceae

Nomenclature

Marsilea crenata C.Presl, Rel. Haenk. 1: 84, t. 12, f. 13. 1825; Holttum, Rev. Fl. Malaya ed. 1, 2: 619. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 35. 1961; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 112. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 600, f. 60.1–60.3. 1989; Boonkerd & Pollawatn, Pterid. Thailand: 97, 115. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 28. 2007.

Marsilea minuta auct. non L.: Tardieu & C.Chr., Fl. Indo-Chine 7(2): 30. 1939; Newman et al., Checkl. Vasc. Pl. Lao PDR: 28. 2007.

Marsilea quadrifolia auct. non L.: Tardieu & C.Chr., Fl. Indo-Chine 7(2): 30. 1939; Newman et al., Checkl. Vasc. Pl. Lao PDR: 28. 2007; Dy Phon, Dictionary of Plants used in Cambodia: 430. 2000.

Marsilea sp. aff. M. polycarpa Hook. & Grev.: Holttum, Dansk Bot. Ark. 20: 35. 1961.

Description

Rhizome slender, long creeping, irregularly branching, bearing pale brown hairs. Stipes rather close, green, stramineous or pale brown, darker towards base, 2–3 cm long when exposed, or 6–18 cm long in immersed plants, hairy or glabrescent. Leaflets fan-shaped, round and subentire to undulate at apex, broadly cuneate at base, 0.5–2 cm both in length and in breadth, glabrous, or hairy at margin when young. Sporocarps one to several on short stalks placed at base of stipes, oblong, 2–5 mm long, covered with caducous hairs.

Distribution in Thailand

NORTHERN: Chiang Mai, Phitsanulok; NORTH-EASTERN: Phetchabun, Khon Kaen; EASTERN: Chaiyaphum; SOUTH-WESTERN: Kanchanaburi; CENTRAL: Bangkok; PENINSULAR: Krabi.

Distribution in Laos

Champasak, Vientiane.

Distribution in Cambodia

Kompong Cham, Siem Reap.

Wider Distribution

Old World Tropics and Subtropics.

Ecology

In paddy fields, in grooves, in streamlets, in ponds or in marshy places, usually in open sunny places, rather common throughout the country at low or medium altitudes, lower than 1000 m.

IUCN Conservation Assessment

Least Concern (LC) as listed on the IUCN Red List at http://www.iucnredlist.org/apps/redlist/details/168620/0.

Notes

Marsilea is in great need of critical revision.  In Thailand only one species was recognised in the Flora of Thailand, namely Marsilea crenata C.Presl. However, in various works from Cambodia and Laos three species have been recognised, Marsilea minuta L., M. quadrifolia L. and M. crenata. This material is very variable and several specimens identified under the first two names are sterile and indeterminable.  In the material that is determinable we can identify only one species throughout Thailand, Laos and Cambodia, which is very variable in size.  We refer all of this material to Marsilea crenata pending a critical revision of the genus in Asia. Young shoots can be eaten raw.

Voucher specimens - Laos

Thorel s.n. [P01435582], Champasak (P); Tixier s.n. [P01435606], Vientiane, Chinaimo [sterile specimen] (P).

Voucher specimens - Cambodia

Schmid s.n. [P01575012], Kompong Cham [sterile ] (P); Martin 128, Siem Reap [sterile ] (P).