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Notes - Invasions of angiosperm tissues by filamentous algae / Aliens - Urtica membranacea 29including coffee, tea and other Camellias(A.S.C.C. 2003; Canter-Lund 1996; Gorsuch2004; Lopez-Bautista et al. 2002). There is alsoindirect evidence, from DNA and other analyses,of Chlorophyte algae with the roots of rice(Oryza) grown in flooded soil pots (Ikenaga etal. 2004).My initial studies of aquatic angiosperm roots(Oliver 2004, 2005a, b & c) have been cloudedto some extent by failure to identify many oftherather featureless extracellular 0.5-10J! greenbodies. Some microphoto interpretations mayhave been wrong. The candidates includedextruded or autolysed angiosperm chloroplasts,extruded grana, and endophytes. In particular,the green 'dimpled discs', (diam. 2.5 J!) wouldseem to be extruded or parietal angiosperm rootchloroplasts. The extracellular green bodies justvisible in microphoto @ in this study were 0.5-2J! in diameter. However some of the greatvariety of undoubted unicellular algae which areoften to be found within the root caps of Lemnaand Azolla can occasionally penetrate the rootcortex tissues of these two genera, and also ofElodea and Callitriche (Oliver 2006). To date,Entocladia is the only identified algal rootendophyte of aquatic angiosperms that I havefound on more than four separate occasions, asin this study.Acknowledgements - my thanks again to Dr HansSluiman of the Royal Botanic Garden, Edinburgh,and to Joan & Brian Davis for help with the colourmicrophotos.ReferencesALLABY, M. 1998. Oxford dictionary of plant sciences.Oxford University Press, Oxford.ASCC (American Samoa Community College). 2003.Plant parasitic algae. Pests & diseases of AmericanSamoa No. 5BIOIMAGES. 2004. The virtual field guide (UK).Chlorochytrium lemnae. www.bioimages.org.ukCANTER-LuND, H. & LUND, lW.G. 1996. FreshwaterAlgae. Biopress Ltd. Bristol.CLEMENT, E.J. 2003. What is Gunnera manicataandwhence? BSB] News 93 52-55.FOGG, G.E. 1975. The growth of plants. PenguinBooks.GORSUCH, C.S. 2004. Algal leaf spot. Clemson Universityforestry images. www.forestry images.orgGRAHAM, L.E. & WILCOX, L.W. 2000. Algae. Prentice-Hall,Inc. NJ.IKENAGA, M. et al. 2004. Community structure ofeukaryotes in rice roots estimated by PCR-DGGEpattern and sequence analyses. Soil Science andPlant Nutrition 50(4) Aug.: 583-589.JOHN, D.M., WHITTON, B.A. & BROOK, AJ. 1993.The freshwater algal flora of the British Isles. CambridgeUniversity Press. Cambridge.LEE, R.E. 1999. Phycology. Cambridge UniversityPress, Cambridge.LOPEZ-BAUTISTA, lM. et al. 2002. The Trentepohlialesrevisted. Constancea 83 1-23.NATHANIELSZ, C.P. & STAFF, l.A. 1975. A mode ofentry of Blue-Green Algae into the apogeotropicroots of Macrozamia communis (Cycad). AmericanJournal of Botany 62(3): 232-235.OUVER, J.E. 2004. Lemna minuta VI Diverse algalendophytes within root tissues. BSB] News 97: 34,35.OUVER, J.E. 2005a. Lemna trisulca. Apparent progressionof algal endophytes into the root centres.BSB] News 98 34.OUVER, lE. 2005b. Algal endophytes within leaf androot tissues of Water Fern (Azollajiliculoides) BSB!News 99 31-32.OUVER, lE. 2005c. Algal endophytes within vascularplant root tissues. BSB] News 10036-38.OUVER, J.E. 2006. Chloroplasts & algae within vascularaquatic plant roots. BSB] News 102 36-38.ROSE, D. 2005. Orange trees. Tree damage alert no.20. Tree Health Division, Forest Research. TheTree Advice Trust.SOUTH, G.R. & WHlTTICK, A. 1987. Phycology.Blackwell Scientific Publications.TREMOUILLAUX-GUlLLER, J. et al. 2002. Discovery ofan endophytic alga in Ginkgo biloba. AmericanJournal of Botany 89: 727-733.VAN DEN HOEK, C., MANN, D.G. & JAHNS, H.M.1995. Algae. Cambridge University Press, Cambridge.ALIENSUrtica membranacea, an annual nettle, in Warwick: a first Britishrecord?ANN BOUCHER, Blakesware, 7 Whinlatter Drive, Kendal, Cumbria, LA9 7HEJAMBS PARTRIDGE, 85 Willes Road, Leamington Spa, Warwickshire, CV311BSIn April 2006, A.B., visiting Warwick for herGolden wedding anniversary, discovered morethan a hundred plants of Urtica membranaceaPoiret in a yard in the town centre. These weregrowing between the pavement and rear walls ofcommercial buildings (flower shop, restaurant,antique shops, herbalist) and were alreadyseeding, having over-wintered (see back cover).Their extensive distribution into neighbouringentrances suggested that they had been estab-