fct: Variable to colorize labels, will be converted into factor
ex: The fraction of the plot height by which segments go up and down from the tips; by default, it is half of the 'hang'
lwd: Line width of segments
horiz: Plot on a horizontal tree?
hang: The fraction of the plot height by which labels should hang below the rest of the plot; by default, it is equal to the default 'hang' from hclust which is 0.1