AddTip() adds a tip to a phylogenetic tree at a specified location.

  where =$Nnode * 2 + 2L, size = 1) - 1L,
  label = "New tip",
  edgeLength = 0,
  lengthBelow = NULL,
  nTip = NTip(tree),
  nNode = tree$Nnode,
  rootNode = RootNode(tree)

AddTipEverywhere(tree, label = "New tip", includeRoot = FALSE)



A tree of class phylo.


The node or tip that should form the sister taxon to the new node. To add a new tip at the root, use where = 0. By default, the new tip is added to a random edge.


Character string providing the label to apply to the new tip.


Numeric specifying length of new edge


Numeric specifying length below neighbour at which to graft new edge. Values greater than the length of the edge will result in negative edge lengths. If NULL, the default, the new tip will be added at the midpoint of the broken edge. If inserting at the root (where = 0), a new edge of length lengthBelow will be inserted.

nTip, nNode, rootNode

Optional integer vectors specifying number of tips and nodes in tree, and index of root node. Not checked for correctness: specifying values here trades code safety for a nominal speed increase.


Logical; if TRUE, each position adjacent to the root edge is considered to represent distinct edges; if FALSE, they are treated as a single edge.


AddTip() returns a tree of class phylo with an additional tip at the desired location. AddTipEverywhere() returns a list of class multiPhylo containing the trees produced by adding label to each edge of tree in turn.


AddTip() extends bind.tree, which cannot handle single-taxon trees.

AddTipEverywhere() adds a tip to each edge in turn.


Martin R. Smith (


plot(tree <- BalancedTree(10))
ape::nodelabels(15, 15, bg='green')

plot(AddTip(tree, 15, 'NEW_TIP'))

oldPar <- par(mfrow = c(2, 4), mar = rep(0.3, 4), cex = 0.9)

backbone <- BalancedTree(4)
# Treating the position of the root as instructive:
additions <- AddTipEverywhere(backbone, includeRoot = TRUE)
xx <- lapply(additions, plot)

par(mfrow=c(2, 3))

# Don't treat root edges as distinct:
additions <- AddTipEverywhere(backbone, includeRoot = FALSE)
xx <- lapply(additions, plot)