Family

Ophioglossaceae

Nomenclature

Ophioglossum pendulum L., Sp. Pl. ed. 2: 1518. 1763; Bedd., Handb. Ferns Brit. India: 465, f. 291. 1883; Clausen, Mem. Torrey Bot. Club 19(2): 116, f. 22. 1938; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 9. 1939; Holttum, Rev. Fl. Malaya ed. 1, 2: 40. 1955 [‘1954’]; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 32. 1967; Tagawa & K.Iwats., Acta Phytotax. Geobot. 23: 51. 1968; Tagawa & K.Iwats., Fl. Thailand 3: 37. 1979; Boonkerd & Pollawatn, Pterid. Thailand: 24, 66. 2000. – Ophioderma pendula (L.) C.Presl, Suppl. Tent. Pterid.: 56. 1845; Ching, Fl. Reipubl. Popularis Sin. 2: 10. 1959.

Description

Rhizome horizontal, up to 3 cm long, fleshy, bearing a few fronds. Phyllomophore short, not distinct from trophophyll, up to 20 cm long; trophophyll long and strap-shaped, sometimes bifurcate a few times, 50–100 cm long including the stipes, round to acute at apex, entire, at most 4 cm broad; venation distinct, reticulate forming narrow areoles usually without included veinlets, costae not differentiated; sporophyll arising from middle part of the sterile fronds, simple, with stalks up to 7 cm long; spikes up to 30 cm long. Sporangia to 3 mm in diameter; exospores with fine reticulum , seemingly smooth.

Distribution in Thailand

NORTHERN: Chiang Rai, Phitsanulok; NORTH EASTERN: Loei; SOUTH-WESTERN: Prachuap Khiri Khan; PENINSULAR: Nakhon Si Thammarat, Trang, Yala.

Distribution in Laos

Champasak.

Distribution in Cambodia

Kampot, Koh Kong, Kompong Speu.

Wider Distribution

Palaeotropical.

Ecology

Epiphytic on tree trunks in mixed or evergreen forest at medium altitudes.

Proposed IUCN Conservation Assessment

Least Concern (LC). This species is widespread and not under any known threat.

Notes

In size and form of trophophyll this epiphytic species varies to some extent according to the habitat and the age of the plants, though any taxonomic segregation is not possible.

Voucher specimens - Thailand

Middleton et al. 3764, Prachuap Khiri Khan, Namtok Huay Yang National Park (E).

Voucher specimens - Laos

Poilane 15744, Champasak, N of Pakson (P).

Voucher specimens - Cambodia

Poilane 14795, Kampot (P); Poilane 15245, Kompong Speu, Pnom Thua So (P).