Ophioglossum petiolatum Hook.




Ophioglossum petiolatum Hook., Exot. Fl. 1: t. 56. 1823; Clausen, Mem. Torrey Bot. Club 19(2): 134. 1938; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 7, f. 1.3–1.4 (labelled pedunculosum in error). 1939; Ching, Fl. Reipubl. Popularis Sin. 2: 10, pl. 1, f. 6. 1959; Tagawa & K.Iwats., Fl. Thailand 3: 37. 1979; Boonkerd & Pollawatn, Pterid. Thailand: 25, 66. 2000.

Ophioglossum reticulatum auct. non L.: Bedd., Handb. Ferns Brit. India: 465, f. 290. 1883; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 7. 1939.


Rhizome cylindrical, 2–4 mm in diameter, to 1.2 cm long, bearing many roots. Fronds 12–25 cm long, 1 or 2 on a rhizome; phyllomophore to 10 cm long; trophophyll variable in size and form, ovate to oblong, round to moderately acute at apex, or acute in some cases, cuneate, round or more commonly deeply cordate at base, 1.5–6.5 cm long, 1.5–5 cm broad; costae not differentiated; veins reticulate, areoles visible, many, free included veinlets often present, simple or branched; texture softly herbaceous, rather fleshy; sporophyll simple, with stalks of 6–12 cm in length; spikes 1.5–4.5cm long. Sporangia up to 0.5 mm in diameter; spores dark, exospores with fine reticulum , seemingly smooth.

Distribution in Thailand

NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Lampang, Kamphaeng Phet; NORTH-EASTERN: Loei; SOUTH-WESTERN: Kanchanaburi; CENTRAL: Bangkok; SOUTH-EASTERN: Chanthaburi; PENINSULAR: Surat Thani.

Distribution in Cambodia


Wider Distribution



Terrestrial in open grassy ground or on mountain slopes in light shade at low to medium altitudes.

Proposed IUCN Conservation Assessment

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


Thai specimens are really variable in size and form of the trophophyll, though the spore character is rather constant.

Voucher specimens - Thailand

Larsen & Warncke 2927, Chiang Mai, Khun Klong (P); Unknown s.n. [ex Herb. Kerr], Kamphaeng Phet, Hue Pa Yo Ki [P01591693] (P).

Voucher specimens - Cambodia

Poilane 15253, Pursat, Ko Virk (P).





Trophophyll (sterile part of frond)

Trophophyll (sterile part of frond)

Sprophyll (fertile part of frond)

Sprophyll (fertile part of frond)

Mature sporophyll (fertile part of frond)

Mature sporophyll (fertile part of frond)

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