Hydrocharitaceae

Najadaceae

Blyxa Noronha ex Thouars

Last edited by Pieter B. Pelser, 1 February 2024
  1. Blyxa aubertii Rich., Mem. Cl. Sci. Math. Inst. Natl. France 1811 (1814) 19; Hartog, Fl. Males. ser. 1, 5 (1957) 390. Distribution: Africa, Asia, Australia, Madagascar, Philippines. PALAWAN (photos). Notes: 0-1250m. Conservation status: Least Concern (IUCN 3.1). Native.
  2. Blyxa echinosperma (C.B.Clarke) Hook.f., Fl. Brit. India 5 (1888) 661; Hartog, Fl. Males. ser. 1, 5 (1957) 391; ≡ Blyxa aubertii var. echinosperma (C.B.Clarke) C.D.K.Cook & Lüönd, Aquatic Bot. 15 (1983) 14; Steenis & W.J.de Wilde, Addenda, corrigenda & emendanda, Fl. Males. ser. 1, 10 (1989) 717; ≡ Hydrotrophus echinospermus C.B.Clarke, J. Linn. Soc., Bot. 14 (1873) 8. ≠ Blyxa octandra auct. non (Roxb.) Planch. ex Thwaites; Merr., PJS 7 c (1912) Bot. 73; EPFP 1 (1922) 27. Distribution: Asia, Australia, Philippines. LUZON, PALAWAN. Notes: 0-250m. Native.
  3. Blyxa novoguineensis Hartog, Acta Bot. Neerl. 6 (1957) 47; Fl. Males. ser. 1, 5 (1957) 393; Addenda, corrigenda et emendanda, Fl. Males. ser. 1, 6 (1972) 952. Distribution: New Guinea, Philippines. LUZON: Benguet. Notes: Based on sterile specimen collected by Jacobs from Mt Tabayoc. Native.

Possibly present

  1. Blyxa octandra (Roxb.) Planch. ex Thwaites, Enum. Pl. Zeyl. (1864) 332; ≡ Vallisneria octandra Roxb., Pl. Coromandel 2 (1802) 34. Distribution: Andaman Isls, Australia, Bangladesh, China, India, Myanmar, New Guinea, Sri Lanka, Vietnam. Notes: Reported for the Philippines by Moody (1989) as a weed in rice, but no specimens cited.

Elodea Michx. (Not native)

Last edited by Pieter B. Pelser, 4 November 2017
  1. Elodea nuttallii (Planch.) H.St.John, Rhodora 22 (1920) 29; ≡ Anacharis nuttallii Planch., Ann. Sci. Nat. (Paris), 3rd Sér. 11 (1849) 74. Distribution: N America. Notes: Naturalized in Philippines? Naturalized.

Enhalus Rich.

Last edited by Pieter B. Pelser, 14 July 2026
  1. Enhalus acoroides (L.f.) Royle, Ill. Bot. Himal. Mts. (Royle) 10 (1839) 377; Steudel, Nomencl. ed. 2, 1 (1840) 554; Merrill, EPFP 1 (1923) 27; Hartog, Fl. Males. ser. 1, 5 (1957) 402; Addenda, corrigenda et emendanda, Fl. Males. ser. 1, 6 (1972) 952; ≡ Stratiotes acoroides L.f., Suppl. Pl. (1782) 268. Distribution: Africa, Andaman Isls, Australia, Bismarck Arch, Borneo, Cambodia, India, Indian Ocean, Java, Lesser Sunda Isls, Madagascar, Malay Peninsula, Middle East, Myanmar, New Caledonia, New Guinea, Nicobar Isls, Pacific Ocean, Philippines, Ryukyu Isls, Solomon Isls, Sri Lanka, Sulawesi, Sumatra, Thailand, Vietnam. BASILAN, BORACAY (photos), BUSUANGA, CATANDUANES, CEBU, LITTLE SANTA CRUZ, LUZON: Albay, Batangas, Pangasinan, Quezon, Sorsogon, Zambales (photos), MACTAN, MARINDUQUE, MAWES, MINDANAO: Davao Oriental (photos), Zamboanga del Norte (photos), Zamboanga del Sur, MINDORO, NEGROS, PALAWAN, PANGASINAN IS, PANIQUIAN, PANUBIGAN ISLS, SIQUIJOR, SUYAC. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.

Halophila Thouars

Last edited by Pieter B. Pelser, 23 July 2026
  1. Halophila beccarii Asch., Nuovo Giorn. Bot. Ital. 3 (1871) 302; Merr., Fl. Manila (1912) 70; Merrill, EPFP 1 (1923) 25; Hartog, Fl. Males. ser. 1, 5 (1957) 411; Kuo, Plants 9 (2020) 1732: 15. Distribution: Borneo, Myanmar, Philippines, Sri Lanka, Vietnam. LUZON: NCR, Pangasinan. Notes: Known from Manila Bay. Seagrass. Below 0m. Conservation status: Vulnerable (IUCN 3.1). Native.
  2. Halophila decipiens Ostenf., Bot. Tidsskr. 24 (1902) 260; Fortes, PJS 142 (2013) 96; Kuo, Plants 9 (2020) 1732: 14. Distribution: Africa, America, Australia, Bangladesh, Caribbean, India, Indian Ocean, Java, Moluccas, Myanmar, New Caledonia, Pacific Ocean, Philippines, Ryukyu Isls, Sri Lanka, Taiwan, Vietnam. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.
  3. Halophila gaudichaudii J.Kuo, Acta Phytotax. Geobot. 57 (2006) 145; Kuo, Plants 9 (2020) 1732: 9. Distribution: Africa, Indian Ocean, Pacific Ocean, Philippines. LUZON: NCR. Notes: Seagrass. Below 0m. Native.
  4. Halophila major (Zoll.) Miq., Fl. Ned. Ind. 3 (1856) 230; Kuo, Plants 9 (2020) 1732: 8; ≡ Lemnopsis major Zoll., Syst. Verz. (Zollinger) 1 (1854) 75; Type: from Indonesia. Distribution: China to Malesia and Pacific Ocean, Philippines. KALANGGAMAN, MARIQUIT, MINDANAO: Zamboanga del Sur, MINDORO, PALAWAN, PANGASINAN IS, PANGLAO, SIQUIJOR, SUYAC. Notes: Seagrass. Below 0m. Native.
  5. Halophila minor (Zoll.) Hartog, Fl. Males., 1st Ser. 5 (1957) 410; Kuo, Plants 9 (2020) 1732: 9; ≡ Lemnopsis minor Zoll., Syst. Verz. (Zollinger) 1 (1854) 75. ≠ Halophila ovata auct. non Gaudich.; Merr., Fl. Manila (1912) 70; EPFP 1 (1922) 26. Distribution: Africa, Australia, China, India, Indian Ocean, Java, Lesser Sunda Isls, Malay Peninsula, Moluccas, New Caledonia, New Guinea, Pacific Ocean, Philippines, Ryukyu Isls, Solomon Isls, Sulawesi, Sumatra, Taiwan, Thailand, Vietnam. BORACAY (photos), LUZON: Albay, NCR, MINDANAO: Zamboanga del Norte (photos), NEGROS, SIQUIJOR. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.
  6. Halophila ovalis (R.Br.) Hook.f., Bot. Antarct. Voy. III. (Fl. Tasman.). 2 (1860) 45; Merrill, EPFP 1 (1923) 26; Hartog, Fl. Males. ser. 1, 5 (1957) 408; Kuo, Plants 9 (2020) 1732: 8; ≡ Caulinia ovalis R.Br., Prodr. Fl. Nov. Holland. (1810) 339; Type: from Australia. Distribution: Africa, Australia, Indian Ocean, Japan, Java, Lesser Sunda Isls, Madagascar, Malay Peninsula, Middle East, Moluccas, New Guinea, Pacific Ocean, Philippines, Singapore, Sulawesi. BANCORAN, BILIRAN, BISUCAY, BOHOL, CATANDUANES, CEBU, CUENCO ISL, CUYO, HUNDRED ISLS, INATUNGLAN, KINDOT, LUZON: Albay, Batangas, Pangasinan, Sorsogon, MAKESI, MARIQUIT, MINDANAO: Davao Oriental (photos), Davao del Sur, Zamboanga, Zamboanga del Sur, MINDORO, NEGROS, PALAWAN, PANIQUIAN, SAMAL, SIQUIJOR, SULU ARCHIPELAGO, TAGANAK, TAGAWAYAN, TICTABON. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.
    • ssp. ovalis. Distribution: Africa, Australia, Indian Ocean, Japan, Java, Lesser Sunda Isls, Madagascar, Malay Peninsula, Middle East, Moluccas, New Guinea, Pacific Ocean, Philippines, Singapore, Sulawesi. BANCORAN, CEBU, LUZON: Sorsogon (photos), MINDANAO: Zamboanga, MINDORO, PALAWAN. Notes: Seagrass. Below 0m. Native.
  7. Halophila spinulosa (R.Br.) Asch., Anl. Wiss. Beobacht. Reisen (1875) 368; Merrill, EPFP 1 (1923) 26; Hartog, Fl. Males. ser. 1, 5 (1957) 412; Kuo, Plants 9 (2020) 1732: 17; ≡ Caulinia spinulosa R.Br., Prodr. Fl. Nov. Holland. (1810) 339. Distribution: Australia, Java, Malay Peninsula, New Guinea, Philippines, Singapore. FONDEADO, ILACAON, LUZON: Camarines, NCR, MINDANAO: Davao del Sur, MINDORO, PALAWAN. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.

Hydrilla Rich.

Last edited by Pieter B. Pelser, 4 November 2017
  1. Hydrilla verticillata (L.f.) Royle, Ill. Bot. Himal. Mts. (Royle) 10 (1839) 376; Merr., Fl. Manila (1912) 69; Merrill, EPFP 1 (1923) 26; Hartog, Fl. Males. ser. 1, 5 (1957) 385; Odulio et al., Biodivers. Data J. 14 (2026) 20; ≡ Serpicula verticillata L.f., Suppl. Pl. (1782) 416. Distribution: Afghanistan, Africa, Australia, Bangladesh, Borneo, Cambodia, China, Continental Asia, Europe, India, Japan, Java, Korea, Lesser Sunda Isls, Malay Peninsula, Middle East, Moluccas, Myanmar, Nepal, New Guinea, Pakistan, Philippines, Ryukyu Isls, Sri Lanka, Sulawesi, Sumatra, Taiwan, Thailand, Tibet, Vietnam. LEYTE, LUZON: Bulacan, Cagayan, Laguna, NCR, Sorsogon, MINDANAO: Lanao del Sur, Sultan Kudarat, SAMAR. Notes: 0-2000m. Conservation status: Least Concern (IUCN 3.1). Native.

Hydrocharis L.

Last edited by Pieter B. Pelser, 4 November 2017
  1. Hydrocharis dubia (Blume) Backer, Handb. Fl. Java 1 (1925) 64; Hartog, Fl. Males. ser. 1, 5 (1957) 394; ≡ Pontederia dubia Blume, Enum. Pl. Javae (1827) 33. = Boottia renifolia Merr., PJS 4c (1909) 247; Merrill, EPFP 1 (1923) 27. Distribution: Bangladesh, China, India, Japan, Java, Korea, Myanmar, New Guinea, Philippines, Ryukyu Isls, Sulawesi, Taiwan, Thailand, Vietnam. LUZON: Camarines, Camarines Sur. Notes: 0-1200m. Conservation status: Least Concern (IUCN 3.1). Native.

Najas L.

Last edited by Pieter B. Pelser, 4 November 2017
  1. Najas graminea Delile, Fl. Aegypt.-Arab. (1812) 282; Merr., Fl. Manila (1912) 68; Merrill, EPFP 1 (1923) 24. Distribution: GUIMARAS, LUZON: Benguet, Ifugao, Laguna, NCR, Nueva Vizcaya, MINDANAO: Zamboanga, NEGROS (photos). Notes: 0-400(-1400)m. Conservation status: Least Concern (IUCN 3.1). Native.
    • var. graminea. Distribution: Africa to New Caledonia, Philippines. LUZON: Nueva Vizcaya. Native.
  2. Najas indica (Willd.) Cham., Linnaea 4 (1829) 501; ≡ Caulinia indica Willd., Mém. Acad. Roy. Sci. Hist. (Berlin) 1798 (1801) 89. = Najas palustris Blanco, Fl. Filip., 1st Ed. (1837) 660; Merrill, EPFP 1 (1923) 25. Distribution: Philippines, Tropical & Subtropical Asia. LUZON: Laguna, NCR, Pampanga, Pangasinan, Rizal, Sorsogon, MINDANAO: Zamboanga. Notes: 0-1000m. Conservation status: Least Concern (IUCN 3.1). Native.
  3. Najas malesiana W.J.de Wilde, Acta Bot. Neerl. 10 (1961) 168. Distribution: India to Malesia, Philippines. Notes: 0-900(-1000)m. Conservation status: Least Concern (IUCN 3.1). Native.
  4. Najas minor All., Auct. Syn. Meth. Stirp. Hort. Regii Taur. (1773) 3. Distribution: Africa, Eurasia, Philippines. Conservation status: Least Concern (IUCN 3.1). Native.
  5. Najas tenuifolia R.Br., Prodr. Fl. Nov. Holland. (1810) 345. Notes: 0-700(-1200)m. Conservation status: Least Concern (IUCN 3.1). Native.
    • ssp. pseudograminea (W.Koch) W.J.de Wilde, Fl. Males., 1st Ser. 6 (1962) 168; ≡ Najas pseudograminea W.Koch, Ber. Schweiz. Bot. Ges. 44 (1935) 339. Native.
      • var. pseudograminea. Distribution: Australia, Hong Kong, Philippines, Thailand. Native.

Ottelia Pers.

Last edited by Pieter B. Pelser, 12 June 2026
  1. Ottelia alismoides (L.) Pers., Syn. Pl. (Pers.) 1 (1805) 400; Merr., Fl. Manila (1912) 70; Merrill, EPFP 1 (1923) 27; Hartog, Fl. Males. ser. 1, 5 (1957) 398; ≡ Stratiotes alismoides L., Sp. Pl., 1st Ed. (1753) 535. = Damasonium lancifolium C.Presl, Reliq. Haenk. 1 (1827) 89. Distribution: Africa, Australia, China, India, Japan, Philippines, Solomon Isls. LUZON: Bataan, Bulacan, Cagayan, Camarines Sur (photos), Ifugao, Ilocos Norte, NCR, Pangasinan, Quezon, Rizal, Sorsogon, MINDANAO: Agusan del Norte (photos), Lanao del Norte (photos), Lanao del Sur, MINDORO. Notes: Widely distributed from NE Africa and common in SE Asia, extending from India eastwards to China and Japan, southward throughout Malesia to tropical Australia and the Solomon Isls. 0-700(-1000)m. Conservation status: Least Concern (IUCN 3.1). Native.

Thalassia Banks ex K.D.Koenig

Last edited by Pieter B. Pelser, 28 July 2025
  1. Thalassia hemprichii (Ehrenb. ex Solms) Asch., Petermanns Geogr. Mitt. 17 (1871) 242; Merr., Fl. Manila (1912) 71; Merrill, EPFP 1 (1923) 27; Hartog, Fl. Males. ser. 1, 5 (1957) 406; ≡ Schizotheca hemprichii Ehrenb. ex Solms, Abh. Königl. Akad. Wiss. Berlin 1832 (1832) 429. Distribution: Africa, Andaman Isls, Australia, Bismarck Arch, Borneo, India, Indian Ocean, Java, Lesser Sunda Isls, Malay Peninsula, Middle East, Moluccas, Myanmar, New Caledonia, Nicobar Isls, Pacific Ocean, Philippines, Ryukyu Isls, Solomon Isls, Sri Lanka, Sulawesi, Sumatra, Taiwan, Thailand, Vietnam. ALABAT, BAJA HANURA, BISUCAY, CATANDUANES, CAWILI, CEBU, COCORO, HINGOTANAN, LUZON: Albay, Batangas (photos), Zambales (photos), MACTAN, MINDANAO: Davao Oriental (photos), Zamboanga del Norte (photos), Zamboanga del Sur, MINDORO, NEGROS, PALAWAN, SAMAR, SIQUIJOR, SUYAC, TAGAWAYAN, UBIAN. Notes: Seagrass. Below 0m. Conservation status: Least Concern (IUCN 3.1). Native.

Vallisneria L.

Last edited by Pieter B. Pelser, 12 May 2025
  1. Vallisneria nana R.Br., Prodr. Fl. Nov. Holland. (1810) 345. = ?Vallisneria gigantea Graebn., Bot. Jahrb. Syst. 49 (1912) 68; Merr., Fl. Manila (1912) 69; Merrill, EPFP 1 (1923) 26; Hartog, Fl. Males. ser. 1, 5 (1957) 388; Les et al., Syst. Bot. 33 (2008) 62; Type: from New Guinea. ≠ Vallisneria natans auct. non (Lour.) H.Hara; Steenis, Addenda, Corrigenda et emendanda, Fl. Males. ser. 1, 7 (1974) 828. Distribution: Australia, Cambodia, New Caledonia, New Guinea, Philippines. LUZON: Laguna, MINDANAO: Lanao del Norte (photos), MINDORO. Notes: Note by P.B. Pelser (10-Apr-2022): Distribution as per Plants of the World Online, but there appears to be some confusion around the delimitation of Vallisneria species, including in the Philippines. See also the use of the names Vallisneria spiralis L. var. denseserrulata Makino and Vallisneria americana Michx. var. americana for Philippine plants by Lowden (1982). 0-300m. Native.

References