How to extract node position from boot.hclust object (pvclust)?

Question

I know I can obtain the au/bp number from the final object from pvclust, but I could not figure out which of the samples or edges are associated with it. What I am trying to do is to assign the au value to the samples. Thanks!

data(lung)
lung.pv <- pvclust(lung, nboot=10)
lung.pv$edges    ######## how is this list sorted??
head(lung.pv$edges)
        au        bp     se.au      se.bp          v         c      pchi
1 1.000000 1.0000000 0.0000000 0.00000000  0.0000000 0.0000000 0.0000000
2 1.000000 1.0000000 0.0000000 0.00000000  0.0000000 0.0000000 0.0000000
3 1.000000 1.0000000 0.0000000 0.00000000  0.0000000 0.0000000 0.0000000
4 1.000000 1.0000000 0.0000000 0.00000000  0.0000000 0.0000000 0.0000000
5 1.000000 1.0000000 0.0000000 0.00000000  0.0000000 0.0000000 0.0000000
6 0.904316 0.6440696 0.1353608 0.05082595 -0.8379504 0.4685922 0.9273748