Hi Josh,
Thank you very much for your kind response.
My purpose is to find a complete (as complete as possible) flowering plants phylogeny.
And in my analysis a few steps would be focused on certain lineages (including around 200 species, for example). I was actually also trying to find a way to extract the topology (It is certainly good to have branch length information) for certain species out of the big phylogeny.
I agree with your suggestion to construct a phylogeny from scratch using molecular data as done by the following studies.
Soltis D., Smith S.A., Cellinese N., Wurdack K.J., Tank D.C., Brockington S.F., Refulio-rodriguez N., Walker J.B., Moore M.J., Carlsward B.S., Bell C., Latvis M., Crawley S., Black C., Diouf D., Xi Z., Rushworth C.A., Gitzendanner M.A., Sytsma K.J., Qiu Y., Hilu K., Davis C., Sanderson M.J., Beaman R.S., Olmstead R., Judd W., Donoghue M., & Soltis P. 2011. Angiosperm phylogeny: 17 genes, 640 taxa. American Journal of Botany, .
Smith SA, Beaulieu JM, Stamatakis A, Donoghue MJ (2011) Understanding angiosperm diversification using small and large phylogenetic trees. American Journal of Botany 98(3): 404-414. doi:10.3732/ajb.1000481
AND
http://phylota.net/pb/Download.htm
By the way, how many species are you processing?
Kind Regards,
Lhl
Currently, i am focusing on those studies of large phylogeny.