Arguments
tree
an object of class "phylo". If not supplied, the function will obtain the last plotted phylogeny from the environmental variable last_plot.phylo.
text
desired clade label text.
node
node number for the most recent common ancestor of members of the clade.
offset
offset (as a multiplier of character width) for the label. Defaults to offset=1 if tree is supplied or offset=8 otherwise.
wing.length
length of the wings to add to the top & bottom of the label bar (in character widths).
cex
character expansion factor.
orientation
orientation of the text. Can be orientation = "vertical" (the default) or "horizontal".