@article {Graham1998,
	title = {Phylogenetic congruence and discordance among one morphological and three molecular data sets from {Pontederiaceae}},
	journal = {Systematic Biology},
	volume = {47},
	number = {4},
	year = {1998},
	pages = {545{\textendash}567},
	author = {Graham, Sean W. and Kohn, Joshua R. and Morton, Brian R. and Eckenwalder, James E. and Barrett, Spencer C.H.}
}
