As a general rule, Lin, I check The Plant List only when something isn't listed on any other taxonomic database. It's the most comprehensive database, but it also has many obsolete entries.
The information in your TPL link is dated 1993, the most recent date for the ITIS entry is 2011, and the Catalogue of Life entry is dated 15 August 2013, so it would be the most up-to-date information.
http://www.catalogueoflife.org...
