- \item{br}{either an R function used to generate the branch lengths
- (\code{rtree} or \code{NULL} to give no branch lengths) or the
- coalescence times (\code{rcoal}). For the latter, a genuine
- coalescent tree is simulated by default.}
- \item{...}{further argument(s) to be passed to \code{br}.}
+ \item{br}{one of the following: (i) an R function used to generate the
+ branch lengths (\code{rtree}; use \code{NULL} to simulate only a
+ topology), or the coalescence times (\code{rcoal}); (ii) a character
+ to simulate a genuine coalescent tree for \code{rcoal} (the
+ default); or (iii) a numeric vector for the branch lengths or the
+ coalescence times.}
+ \item{\dots}{further argument(s) to be passed to \code{br}.}