Hexisea and Scaphyglottis used to be separated because Hexisea flowers have the labellum partially fused to the column base; it is not motile and is abruptly bent down after the column, furthermore, the columns of their flowers do not show a well developed foot.
Previously to the name Hexisea, sometimes misspelled in literature as Hexesea and Hexisia, was rejected by the Intenational Code of Botanical Nomenclature against Scaphyglottis, its five accepted species were, H. arctata, H. bidentata, H. imbricata, H. lankesteri and H. oppositifolia.
From these, three were moved to Scaphyglottis before 1993, when Robert Louis Dressler published his Field guide to the orchids of Costa Rica and Panama.
The remaining two species were H. bidentata and H. imbricata, which were moved to Scaphyglottis in 1994. They are the most showy Scaphyglottis species because they have red flowers. Both are pollinated by hummingbirds and can be separated by a yellow callus H. imbricata has on the labellum and in H. bidentata is replaced by a triangular purple mark that goes down towards its apex.
List of synonyms
- Hexisea Lindl., J. Bot. (Hooker) 1: 7 (1834) see Scaphyglottis.
- H. amparoana (Schltr.) Ames, F.T.Hubb. & C.Schweinf., Bot. Mus. Leafl. 3: 40 (1934) see Scaphyglottis amparoana.
- H. arctata Dressler, Orquídea (Mexico City), n.s., 7: 223 (1979) see Scaphyglottis arctata.
- H. aurea (Rchb.f.) Dressler, Taxon 13: 246 (1964) see Scaphyglottis aurea.
- H. bicornis (Lindl.) Dressler, Phytologia 21: 442 (1971) see Scaphyglottis bicornis.
- H. bidentata Lindl., J. Bot. (Hooker) 1: 8 (1834) see Scaphyglottis bidentata.
- H. bidentata var. imbricata (Lindl.) C.Schweinf., Bot. Mus. Leafl. 15: 106 (1951) see Scaphyglottis imbricata.
- H. cuniculata (Schltr.) Ames, Schedul. Orchid. 9: 48 (1925) see Scaphyglottis cuniculata.
- H. imbricata (Lindl.) Rchb.f. in W.G.Walpers, Ann. Bot. Syst. 6: 470 (1862) see Scaphyglottis imbricata.
- H. lankesteri Ames, Schedul. Orchid. 9: 47 (1925) see Scaphyglottis subulata.
- H. oppositifolia (A.Rich. & Galeotti) Rchb.f. in W.G.Walpers, Ann. Bot. Syst. 6: 470 (1862) see Scaphyglottis imbricata.
- H. reflexa (Lindl.) Rchb.f. ex Griseb., Fl. Brit. W. I.: 623 (1864) see Scaphyglottis reflexa.
- H. reflexa Rchb.f., Linnaea 41: 131 (1877) see Scaphyglottis emarginata.
- H. sigmoidea Ames & C.Schweinf., Schedul. Orchid. 8: 39 (1925) see Scaphyglottis sigmoidea.