Fluvisols of the Nature Reserve (NR) Chynoriansky luh floodplain situated at the confluence of the rivers Bebrava and Nitra in W Slovakia have been formed from argillic, slightly carbonaceous alluvia deposed on gravel-sand terrace. In the neutral soils gleyed at depths of ≤ 50 cm, the ground water fluctuates in general from 0.5–2.5 m. The group of forest types Ulmeto-Fraxinetum carpineum is dominated by the species Allium ursinum, locally associated with Hedera helix, Mercurialis perennis and Galeobdolon luteum species in the 5 phytocoenoses. The mean parameter values of these species (folloving the same sequence) were: numbers of shoots per m2 92 ± 42.7 s.d (standard deviation), 97 ± 103 s.d., 15 ± 10 s.d. and 27 ± 18 s.d., plant length 44.9 cm ± 7.3 s.d., 14.7 cm ± 2.9 s.d., 33.05 cm ± 7.4 s.d. and 31.0 cm ± 13.4 s.d., shoot weight 0.425 g ± 0.166 s.d., 0.240 g ± 0.092 s.d., 0.363 g ± 0.006 s.d. and 0.261 g ± 0.189 s.d., phytomass 42.2 g.m-2 ± 25.7 s.d., 27.68 g.m–2 ± 30.4 s.d., 6.3 g.m–2 ± 5. 3 s.d. and 9.5 g.m–2 ± 10.9 s.d., the energy content 17 742 J.g–1 ± 527 s.d., 18 967 J.g–1 ± 407 s.d., 16 871 J.g–1 ± 322 s.d. and 17 167 J.g–1 ± 102 s.d. The weight of the mean Allium ursinum shoot was 1.468 g, from which were aboveground organs 29%, bulbils 57% and roots 14%. The total primary production in Allium ursinum phytocoenoses was 145.4 g.m–2, from which were aboveground organs 29%, bulbils 58% and roots 13%. The mean shoots lenght of Allium ursinum, Mercurialis perennis and Galeobdolon luteum species growing in the ecological conditions of 5th phytocoenoses differed on significance level P < 0.0001.