{
  "url": "https://openlegislation.uk/eu-regulation-2009-761/annex-VI/appendix-1",
  "json_url": "https://openlegislation.uk/eu-regulation-2009-761/annex-VI/appendix-1.json",
  "legislation": "eur/2009/761",
  "legislation_title": "Commission Regulation (EC) No 761/2009 of 23 July 2009 amending, for the purpose of its adaptation to technical progress, Regulation (EC) No 440/2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2009-761",
  "path": "annex/VI/appendix/1",
  "kind": "appendix",
  "number": "1",
  "heading": "Description of lemna spp.",
  "text": "The aquatic plant commonly referred to as duckweed, Lemna spp., belongs to the family Lemnaceae which has a number of worldwide species in four genera. Their different appearance and taxonomy have been exhaustively described (1)(2). Lemna gibba and L. minor are species representative of temperate areas and are commonly used for toxicity tests. Both species have a floating or submerged discoid stem (frond) and a very thin root emanates from the centre of the lower surface of each frond. Lemna spp. rarely produce flowers and the plants reproduce by vegetatively producing new fronds (3). In comparison with older plants, the younger ones tend to be paler, have shorter roots and consist of two to three fronds of different sizes. The small size of Lemna, its simple structure, asexual reproduction and short generation time makes plants of this genus very suitable for laboratory testing (4)(5).\nBecause of probable interspecies variation in sensitivity, only comparisons of sensitivity within a species are valid.\nExamples of Lemna species which have been used for testing: Species Reference\nLemna aequinoctialis: Eklund, B. (1996). The use of the red alga Ceramium strictum and the duckweed Lemna aequinoctialis in aquatic ecotoxicological bioassays. Licentiate in Philosophy Thesis 1996:2. Dep. of Systems Ecology, Stockholm University.\nLemna major: Clark, N. A. (1925). The rate of reproduction of Lemna major as a function of intensity and duration of light. J. phys. Chem., 29: 935-941.\nLemna minor: United States Environmental Protection Agency (USEPA). (1996). OPPTS 850.4400 Aquatic Plant Toxicity Test Using Lemna spp., ‘Public draft’. EPA 712-C-96-156. 8pp.\nAssociation Française de Normalisation (AFNOR). (1996). XP T 90-337: Détermination de l’inhibition de la croissance de Lemna minor. 10pp.\nSwedish Standards Institute (SIS). (1995). Water quality — Determination of growth inhibition (7-d) Lemna minor, duckweed. SS 02 82 13. 15pp. (in Swedish).\nLemna gibba: ASTM International. (2003). Standard Guide for Conducting Static Toxicity Test With Lemna gibba G3. E 1415-91 (Reapproved 1998). pp. 733-742.\nUnited States Environmental Protection Agency (USEPA). (1996). OPPTS 850.4400 Aquatic Plant Toxicity Test Using Lemna spp., ‘Public draft’. EPA 712-C-96-156. 8pp.\nLemna paucicostata: Nasu, Y., Kugimoto, M. (1981). Lemna (duckweed) as an indicator of water pollution. I. The sensitivity of Lemna paucicostata to heavy metals. Arch. Environ. Contam. Toxicol., 10:1959-1969.\nLemna perpusilla: Clark, J. R. et al. (1981). Accumulation and depuration of metals by duckweed (Lemna perpusilla). Ecotoxicol. Environ. Saf., 5:87-96.\nLemna trisulca: Huebert, D. B., Shay, J. M. (1993). Considerations in the assessment of toxicity using duckweeds. Environ. Toxicol. and Chem., 12:481-483.\nLemna valdiviana: Hutchinson, T.C., Czyrska, H. (1975). Heavy metal toxicity and synergism to floating aquatic weeds. Verh.-Int. Ver. Limnol., 19:2102-2111.\nSources of Lemna species\nUniversity of Toronto Culture Collection of Algae and Cyanobacteria\nDepartment of Botany, University of Toronto\nToronto, Ontario, Canada, M5S 3 B2\nTel. +1-416-978-3641\nFax +1-416-978-5878\ne-mail: jacreman@botany.utoronto.ca\nhttp://www.botany.utoronto.ca/utcc\nNorth Carolina State University\nForestry Dept\nDuckweed Culture Collection\nCampus Box 8002\nRaleigh, NC 27695-8002\nUNITED STATES\nTel. 001 (919) 515-7572\nastomp@unity.ncsu.edu\nInstitute of Applied Environmental Research (ITM) Stockholm University\nSE-106 91 Stockholm\nSWEDEN\nTel. +46 86747240\nFax +46 86747636\nFederal Environmental Agency (UBA)\nFG III 3.4\nSchichauweg 58\n12307 Berlin\nGERMANY\ne-mail: lemna@uba.de\nhttp://www.umweltbundesamt.de/contact.htm\nLiterature\n(1) Hillman, W.S. (1961). The Lemnaceae or duckweeds: A review of the descriptive and experimental literature. The Botanical Review, 27:221-287.\n(2) Landolt, E. (1986). Biosystematic investigations in the family of duckweed (Lemnaceae). Vol. 2. Geobotanischen Inst. ETH, Stiftung Rubel, Zürich, Switzerland.\n(3) Björndahl, G. (1982). Growth performance, nutrient uptake and human utilization of duckweeds (Lemnaceae family). ISBN 82-991150-0-0. The Agricultural Research Council of Norway, University of Oslo.\n(4) Wang, W. (1986). Toxicity tests of aquatic pollutants by using common duckweed. Environmental Pollution, Ser B, 11:1-14.\n(5) Wang, W. (1990). Literature review on duckweed toxicity testing. Environmental Research, 52:7-22.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2009/761/annex/VI/appendix/1",
    "retrieved_at": "2026-11-01T14:51:19.625001+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}