Helminthostachys zeylanica (L.) Hook.
Family
Ophioglossaceae
Synonyms
Osmunda zeylanica L, Helminthostachys dulcis Kaulfuss.
Vernacular Names
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Malaysia |
Tunjok langit, akar paku, jelai. |
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Indonesia |
Rawu bekubang (Malay, western Sumatra), jajalakan (Sundanese), pakis kaler (Javanese). |
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Philippines |
Tungkud-langit (Tagalog). |
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Thailand |
Kut chong (Northern), tin nok yung (South-eastern, Peninsular), phak nok yung (Eastern). |
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Vietnam |
S[aa]m d[aas]t, r[as]ng re[uf]ng gi[es], s[aa]m b[of]ng bong. |
Geographical Distributions
The exact origin of Helminthostachys zeylanica is unknown but it is widespread at low altitudes from India, Sri Lanka, southern China and Taiwan, throughout Southeast Asia to tropical Australia and the western Pacific.
Description
Helminthostachys zeylanica is a terrestrial fern with short creeping rhizome and measures up to 7 mm in diametre. It is unbranched, bearing fleshy roots laterally and ventrally.
The leaves are in two rows, one or rarely two per growing season. The petiole is 10-60 cm long, fleshy, green or purplish-brown. The leaf is pinnate to subpalmate, measuring 5-25 cm x 10-50 mm, tripartite and herbaceous, with rhomboid to obdeltoid pinnae, measures up to 25 cm long, with a short stalk or subsessile, with a terminal lobe and one or two pairs of sessile lateral lobes. The lobes are lance-shaped, measuring 5-25 cm x 2-5 cm, with wedge-shaped base and decurrent. The margin is entire or finely and irregularly dentate while apex is acuminate. A spike arises from the junction of the petiole and the blade, usually protruding beyond the blade, bearing numerous short branches, each with a group of round sessile sporangia that opens with a longitudinal slit and with small sterile lobes at the apex.
The spores are spherical, trilete, measure 20-40 mm in diametre, granular with coarse, more or less fused and cylindrical projections.
Ecology / Cultivation
Helminthostachys zeylanica grows terrestrially on moist ground, along the bank of streams or on humus-rich slopes in light shade from sea level up to 400 m altitude. In the wild, it is rather difficult to find and is no where very common. Locally, it may grow gregariously.
Line Drawing / Photograph
References
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Plant Resources of South-East Asia No.15(2): Ferns and fern allies.
