Type : "8.
Bidens (
verticillata)
foliis oblongis integris: inferne alternis, superne oppositis, floribus verticillatis.
Hort. cliff. 399.*
Bidens americana procumbens, polygoni folio subtus incano. Houst. mss.
Habitat in Vera Cruce." [protologue].
Mexique, Veracruz, Wm. Houstoun, cultivé dans le jardin de George Clifford III (Hartekamp, Pays-Bas), anonyme s.n. (LT:
BM000646990 [sur
Global plants; ex Herb. Clifford.; cité comme "based on" par S.F. Blake, Torreya, 15(5):
106. 1915 [29/06/1915]).
D'après J. Pruski (2005
in Tropicos): specimen in BM was annotated by S.F. Blake, this coupled with his statement that Linne's name was "based on" this specimen effects lectotypification even without using the word "type".