an object of class "phylo", "contMap", or "densityMap". If not supplied, the function will obtain the last plotted phylogeny from the environmental variable last_plot.phylo.

label of tip or tip or node number. If tree=NULL then the tip or node number must be supplied.

optional arguments to control the shape and size of the arrow including: its length (arrl) in the units of the plot; the length of the arrowhead (hedl); the total angle between the wings in the arrowhead (angle); the line width for the plotted lines (lwd); the offset from the tip or end of tip label, in character widths (offset); and the color (col).