Thalassia hemprichii   (Ehrenberg) Ascherson,  1871 (Seagrass)
Organism information awaits expert curation
Class: Equisetopsida

Image copyrights: McKenzie et al

Rhizomes creeping, branched, brittle, brown to white. Roots single at each node, with a tuft of soft root hairs. Scales ovate, truncate, obtuse at apex, entire along margins, hyaline, convolute, brown, crowded and overlapping near the tip with numerous reddish brown tannin streaks. Shoots upto 30 cm long, sometimes branched, bearing 3-7 leaves at each branch. Stems erect, brownish-black; internodes short, many.
Flowers uniflorous, subtended by spathes. Spathes oblong to lanceolate, acute, obtuse or entire, rarely serrulate at apex, persistent, connate, with many short, brown, tannin dashes. Peduncle of the male inflorescences ca 3 cm long. Pedicel of the male flowers 2-3 mm long. Tepals 3, elliptic. Stamens 3-12, mostly 6-9. Anthers oblong, occasionally forked. Pollen grains globose, yellow. Peduncle of the female inflorescences 1-1.5 cm long, after anthesis elongating to 2-4 cm long. Female flowers subsessile, after anthesis very shortly pedicellate. Tepals 3, elliptic. Margins revolute during anthesis, smooth at inner side, longitudinally ribbed at outer side, hyaline or pale brown, with numerous tannin cells. Ovary conical. Hypanthium 2-3 mm long. Styles 6, 5-7 mm long. Stigmata pale brown, after flowering recurved and subsequently caduceus. Stalks of fruits erect, flattened. Fruits globose, roughly warty, distinctly 3-ridged, with many inconspicuous longitudinal ridge, bursting into 8-13 irregular valves. Beaks prominent. Seeds 3-9, obconical to obovoid, conical part greenish, basal part stout, dark brown. Embryo ellipsoid, white. Fruits in March and April.

Synonym (s)

Common Name (s)
• Alai Vaari (Tamil)
• Kadal Thazhai (Tamil)
• Karumbu Paasi (Tamil)
• Kattai Korai (Tamil)
• Korai Paasi (Tamil)
• Neer Pasalai (Tamil)
• Olai Paasi (Tamil)
Economic Importance and Threats

Habitat:  Reef Associated, Sandy, Muddy, Coastal


• Lakshadweep, Kavaratti (Lat: 10.57) (Long: 72.62) INDIA
• Lakshadweep, Suheli (Lat: 10.08) (Long: 72.28) INDIA
• Lakshadweep, Agatti (Lat: 10.83) (Long: 72.2) INDIA
• Lakshadweep, Minicoy (Lat: 8.12) (Long: 73.3) INDIA
• Andaman and Nicobar Islands, Andamans INDIA
• Andaman and Nicobar Islands, Nicobar INDIA
• Tamil Nadu, Manoli Island (Lat: 9.2) (Long: 79.11) INDIA (Record: 09/2006)
• Tamil Nadu, Tuticorin INDIA (Record: 02/10/1916)
• Tamil Nadu, Mandapam INDIA (Record: 20/04/1988) (Depth: ±4 mts)
• Tamil Nadu, Pamban, Thalaipalem INDIA (Record: 26/09/1987) (Depth: ±2 mts)
• Tamil Nadu, Krusadai Island INDIA (Record: 25/09/1987, 21/04/1988) (Depth: ±3 mts)
• Tamil Nadu, Pamban INDIA (Record: 23/04/1988) (Depth: ±3 mts)
• Tamil Nadu, Rameswaram, Sangumal INDIA (Record: 24/04/1988) (Depth: ±2 mts)
• Tamil Nadu, Hare Island INDIA (Record: 28/04/1988) (Depth: ±1.5 mts)
• Tamil Nadu, Tuticorin Harbour INDIA (Record: 30/04/1988) (Depth: ±3 mts)
• Lakshadweep INDIA
• Tamil Nadu INDIA
• Andaman and Nicobar Islands INDIA
• Tamil Nadu, Thonithurai INDIA
• Tamil Nadu, Pamban INDIA
• Tamil Nadu, Krusadai INDIA
• Tamil Nadu, Manoli Island INDIA
• Tamil Nadu, Gulf of Mannar, Hare Island INDIA
• Tamil Nadu, Tuticorin INDIA
• Palk Bay INDIA
• Tamil Nadu, Gulf of Mannar INDIA
• Tamil Nadu, Gulf of Mannar, Manauli Island INDIA
• Lakshadweep, Kadamatt INDIA
• Lakshadweep, Amini INDIA
• Lakshadweep, Kavaratti INDIA
• Lakshadweep, Kalpeni INDIA
• Lakshadweep, Andrott INDIA
• Andaman and Nicobar Islands, Katchall INDIA
• Andaman and Nicobar Islands, Nancowry INDIA
• Andaman and Nicobar Islands, Great Nicobar Island INDIA
• Palk Bay INDIA (Record: 01/1987-09/1988)
• Tamil Nadu, Rameswaram INDIA (Record: 01/1987-09/1988)
• Tamil Nadu, Krusadai Island INDIA (Record: 01/1987-09/1988)
• Tamil Nadu, Manappadu INDIA (Record: 01/1987-09/1988)
• Tamil Nadu, Nellai Kattabomman, Nadar Uvari INDIA (Record: 01/1987-09/1988)
• Tamil Nadu, Hare Island INDIA (Record: 01/1987-09/1988)

Literature Source(s)
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  • Jagtap, TG and Untawale, AG (1984) Chemical Composition of Marine Macrophytes and their sorrounding water and sediments, from Minicoy, Lakshaweep Indian Journal of Marine Sciences 13 123-125 Available at - NIO, RC Kochi
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  • (2006) Algaebase Available at -
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  • Stoddart, DR and Fosberg, FR (1972) South Indian sand cays Atoll Research Bulletin 161 1-25 Available at -
  • Thangaradjou, T; Nobi, EP; Dilipan, E; Sivakumar, K and Sushila, S (2010) Heavy metal enrichment in seagrasses of Andaman Islands and its implications on the health of the coastal ecosystem Indian Journal of Marine Sciences NISCAIR 39(1) 85-91 Available at -
  • Kaliaperumal, N; Kaladharan, P and Kalimuthu, S (1989) Seaweed and seagrass resources Marine living resources of the union territory of Lakshadweep: An indicative survey with suggestions for development Bulletin of Central Marine Research Institute CMFRI 43 162-176 Available at -
  • Jagtap, T.G. (1992) Marine flora of Nicobar group of islands in Andaman Sea. Indian Journal of Marine Sciences National Institute of Science Communication & Information Resources 21(1) 56-58 Available at - NIO,Goa
  • Parthasathy, N; Ravikumar, K; Ganesan, R and Ramamurthy, K (1991) Distribution of seagrasses along the coast of Tamil Nadu, Southern India Aquatic botany Elsevier 40(1) 145-153 Available at - NIO, Goa.
  • Jagtap, TG (1991) Distribution of seagrasses along the Indian coast Aquatic Botany Elsevier B.V. 40(1) 379-386 Available at - NIO, Goa

Page last updated on:2011-09-29

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