How to put a sample of my data in dendrogram generated with hclust package in R

Question

I want to put in the labels of my dendrogram the samples name that I have in column 1 associated with the environments that I have in column 2, but I cannot find the solution.

I am using this code of hclust package:

d <- dist(mydata, method = "euclidean") # distance matrix
fit <- hclust(d, method="ward.D")
par(cex=0.3, mar=c(5, 8, 4, 1))
plot(fit)