Datraframe
    Site      Date    Habitat    Season    Year     Taxa
    Q1F    08_09_2015  Oak     Autumn   2015-2016   Adonis_flammea
    E2F    08_09_2015  Oak     Autumn   2015-2016   Agrimonia_eupatoria
    Q4F    08_09_2015  Oak     Autumn   2015-2016   Ajuga_chamaepitys
    L1P    08_09_2015  Oak     Autumn   2015-2016   Ajuga
    M2P    08_09_2015  Oak     Autumn   2015-2016   Allium_sativum

Matrix_Rawdata<-acast(Datos,Site~Taxa,fill = 0 )
    Matrix_Rawdata<-data.frame(Matrix_Rawdata)

Plot   Group
   Q1F     1
   E2F     2
   Q4F     1
   L1P     3
   M2P     4

DCA.Rawdata <- decorana(Matrix_Rawdata)
    plot(DCA.Rawdata,
         choices = c(1, 2),
         origin = TRUE,
         display = "sites",
         type = "n",
         cex = 0.5,
         main = "Raw Data",
         xlab = "DCA1 (0.353)",
         ylab = "DCA2 (0.247)")

    points (DCA.Rawdata, col = Site$Group, pch = Site$Group)

Error in plot.xy(xy.coords(x, y), type = type, ...) : invalid graphic symbol