Family

Pteridaceae, subfamily Parkerioideae

Nomenclature

Ceratopteris thalictroides (L.) Brongn., Bull. Sci. Soc. Philom. Paris 1821: 186. 1822; Bedd., Handb. Ferns Brit. India: 123, f. 63. 1883; Christ, Bot. Tidsskr. 24: 113. 1901; C.Chr., Bot. Tidsskr. 32: 249. 1916; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 194, f. 23, 2–3. 1940; Holttum, Rev. Fl. Malaya ed. 1, 2: 578. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 32. 1961; Holttum, Dansk Bot. Ark. 23: 243. 1965; Seidenf., Nat. Hist. Bull. Siam Soc. 19: 87. 1958; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 88. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 107. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 184, f. 14.1. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 104, 125. 2000; Newman et al., Checkl. Vasc. Pl. Lao PDR: 31. 2007. – Acrostichum thalictroides L., Sp. Pl. 1070. 1753.

Acrostichum saliquosum L., Sp. Pl. 2: 1070. 1753. – Ceratopteris saliquosa (L.) Copel., Philipp. J. Sci. 56: 107. 1935

Description

Terrestrial in wet soil or in flooded areas, sometimes a free floating aquatic. Rhizome short, erect, bearing a tuft of fronds, scaly; scales fuscous, thin, entire, ovate and cordate at base. Stipes fleshy, green, up to 40 cm long. Frond dimorphic: sterile lamina bipinnatifid to tripinnatifid, subdeltoid to oblong, usually shorter than the fertile ones, 10–15 cm but in larger ones up to 35 cm long; rachis and pinna-rachis like the upper part of stipe, green; ultimate lobes linear, moderately acute at apex, glabrous; fertile lamina longer, up to 50 by 30 cm, more copiously divided; pinnules divided into linear lobes; ultimate lobes up to 5 cm long and about 2 mm broad. Sporangia on veins except on raised costae of ultimate segments, solitary , large with short stalks.

Distribution in Thailand

NORTHERN: Mae Hong Son, Chiang Mai, Phitsanulok; EASTERN: Buri Ram; SOUTH-WESTERN: Kanchanaburi, Prachuap Khiri Khan; CENTRAL: Pathum Thani, Bangkok; SOUTH-EASTERN: Chon Buri, Chanthaburi, Trat; PENINSULAR: Surat Thani, Phatthalung, Satun.

Distribution in Laos

Champasak, Khammouane.

Distribution in Cambodia

Kandal, Kompong Cham, Ratanakiri.

Wider Distribution

Warmer regions throughout the world.

Ecology

Aquatic or subaquatic in paddy fields usually in open areas, common at low to medium altitudes throughout Thailand. This species is becoming rarer in the areas where herbicides are used.

IUCN Conservation Assessment

Least Concern (LC) as listed on the IUCN Red List at http://www.iucnredlist.org/apps/redlist/details/168862/0.

Voucher specimens - Thailand

Middleton et al. 5466, Krabi, Thanbok Khoranee National Park (E).

Voucher specimens - Laos

Thebaud s.n., Champasak, Se Pian (P).

Voucher specimens - Cambodia

David et al. CL820, Ratanakiri, Along Taveng Road (P).