[R] plot vertical labels along x axis

[Anna H. Pryor]

I know how to print my own labels along the x axis:

plot(1:10,xlab = "My label", axes = FALSE)

axis(1,at=seq(1,10,by=2),labels=c("first","second","third","fourth","fifth"))


Is there a way to make the labels print vertically along the axis rather than 
horizontally?  (I'm not sure if this is even going to look all right, but I 
want to check it out if it is possible.)

Anna