Pontederia sagittata C.Presl, Reliq. Haenk. 1(2): 116. 1827.

Pellegrini, Marco O. O., Horn, Charles N. & Almeida, Rafael F., 2018, Total evidence phylogeny of Pontederiaceae (Commelinales) sheds light on the necessity of its recircumscription and synopsis of Pontederia L., PhytoKeys 108, pp. 25-83 : 25

5.5. Pontederia sagittata C.Presl, Reliq. Haenk. 1(2): 116. 1827.

Pontederia cordata f. sagittata (C.Presl) Solms, Monogr. Phan. 4: 533. 1883.

Pontederia cordata var. sagittata (C.Presl) Schery, Ann. Missouri Bot. Gard. 31: 157. 1944. Holotype. MEXICO. s.loc., fl., fr., s.dat., T.P.X. Haenke s.n. (PRC barcode PRC450416!).

Distribution.

Mexico, Costa Rica, Guatemala, Honduras, Panama and Brazil (states of Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Rio Grande do Sul and Santa Catarina).

Taxonomical notes.

Pontederia sagittata is a poorly circumscribed taxon that is morphologically similar to P. cordata , due to the shape of the blade of their petiolate leaves. However, it is molecularly more closely related to P. ovalis , having in common the anthocarp with sinuate ridges. The disjunctive distribution of P. sagittata is probably related to misidentified specimens and/or the presence of cryptic species in what we currently accept as P. sagittata s.l. Great variation in petiolate leaf shape can be observed throughout its distribution, especially in Brazil. We believe that P. sagittata should be properly studied, using different approaches than traditional taxonomy, in order to solve this issue.