Acta Botanica Croatica, Vol. 73 No. 2, 2014.
Original scientific paper
https://doi.org/10.2478/botcro-2014-0011
Distribution and morphological variations of invasive macrophytes Elodea nuttallii (Planch.) H. St. John and Elodea canadensis Michx in Croatia
Aleksandra Kočić
; Josip Juraj Strossmayer University of Osijek, Department of Biology, Cara Hadrijana 8A, HR-31000 Osijek, Croatia
Janja Horvatić
; Josip Juraj Strossmayer University of Osijek, Department of Biology, Cara Hadrijana 8A, HR-31000 Osijek, Croatia
Sven D. Jelaska
; University of Zagreb, Faculty of Science, Department of Biology, Marulicev trg 20/2, Hr-10000 Zagreb, Croatia
Abstract
The invasive species Elodea nuttallii was recorded for the first time in the Croatian flora in 2006, in the drainage channels of Kopački rit (Baranja). After its establishment, E. nuttallii begins to spread to the eastern and northern part of the drainage channel network from 2006–2009. High water levels are responsible for the linear spreading direction of E. nuttallii, E. nuttallii and E. canadensis show a wide range of morphological variation, which is characteristic of successful invaders. To show morphological variations of two Elodea species, the most impor tant characters indicated in the literature were measured on 24 fresh collected samples from the seven sites in Croatia. In spite of some overlap in leaf length and width between the two Elodea species, the differences of all morphological traits except internode length are statistically significant. In E. nuttallii leaf width, length and internode length show a higher morphological variability as a result of the higher adaptive strategy to environmental parameters. The most reliable morphological characters distinguishing E. nuttallii and E. canadensis are leaf width 0.5 mm below the tip and the angle at the apex. E. nuttallii can be expected to spread to other areas of Croatia.
Keywords
distribution; Elodea canadensis; Elodea nuttallii; invasive species; morphological variation
Hrčak ID:
127807
URI
Publication date:
2.10.2014.
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