Synonymy

In 2004, several other genera were brought into synonymy with Scaphyglottis as the concept is used today:

Hexadesmia This genus containing 27 species was described by Adolphe-Théodore Brongniart in 1843.^[5] It consisted of several different species separated from Scaphyglottis because the flowers had six pollinia instead of four. Because all of these species are in the basal clade of Scaphyglottis, six pollinia seems likely to be the ancestral condition of Scaphyglottis.^[6] Several other authors, including Schlechter and Reichenbach, placed additional species in Hexadesmia.

Leaoa: In 1922, Rudolf Schlechter and Paulo de Campos Porto^[7] erected this small genus for a species that had previously been called Hexadesmia monophylla, which had a very long inflorescence, rather than the short inflorescence typical of Hexadesmia, as well as the typical six pollinia. More species were added to the genus by Leslie Andrew Garay in 1955^[8] and by Freidrich Gustav Brieger in 1976,^[9] bringing the total to four.

Tetragamestus: Heinrich gustav Reichenbach described Tetragamestus modestus in 1854.^[10] Three additional species have been assigned to this genus, the last by Schlechter in 1818.^[11] The most widely known species is T. modestus, a name which can be confused with reichenbachanthus modestus, a synonym of S. brasiliensis. The name Tetragamestus is widely used by orchid enthusiasts, many of whom reject the inclusion of this genus in Scaphyglottis.^[12]

Reichenbachanthus: João Barbosa Rodrigues published Reichenbachanthus modestus in 1882. Four species of pendant epiphytes which occur from Central America to southeastern Brazil in tropical rain forests have been included in this genus, the last in 1997 by Dressler.^[13] The terete (= narrowly cylindrical) pseudobulb is difficult to distinguish from the single terete leaf. The base of the full or slightly trilobate lip forms a nectary together with the column, the column foot, and the base of the lateral sepals. The column is long and thick with an apical anther containing four pollinia. The pale yellow or green flowers feature lanceolate petals, smaller than the sepals.

• Reichenbachanthus modestus, originally published as Fractiunguis brasiliensis and also published in 1877 as Hexisea reflexa (Reichenbach) is now Scaphyglottis reflexa.
• Reichenbachanthus reflexus, also published as Fractiunguis reflexus and Hexisea reflexa is now Scaphyglottis emarginata.
• Reichenbachanthus cuniculatus, originally published as Fractiunguis cuniculatus in 1923, also published as Hexisea cuniculata in 1925, is now Scaphyglottis cuniculata (Schltr.) Dressler (2002).
• Reichenbachanthus subulatus (Schltr.) Dressler (1997) was originally published as Scaphyglottis subulata Schltr. (1910).^[14] It has also been published as Reichenbachanthus lankesteri (Ames) DE Mora-Retana & JB García-Castro (1992)^[15] and Hexisea lankesteri Ames (1925).^[16]

Fractiunguis was published by Schlechter in 1922, and has been considered a synonym of Reichenbachanthus almost from that time.^[17] It consisted of three species:

• Fractiunguis reflexus Schlechter (1922)
• Fractiunguis cuniculatus Schlechter (1923)
• Fractiunguis cuniculatus var gracilis Schlechter (1923)

Hexisea: In 1834, John Lindley published Hexisea bidentata.^[18] The generic epithet refers to the six perianth segments being nearly equal in size and shape. Fourteen species have been placed in this genus before it was reduced to synonymy under Scaphyglottis, despite having priority to Scaphyglottis.

The plants are epiphytic or rupicolous (rock dwelling) and caespitose, sometimes hanging down from branches of trees. They grow naturally in tropical and equatorial, humid, low-altitude forests from southern Mexico to northern and northwestern South America.

The original two species (H. bidentata and H. imbricata, originally published as H. bidentata var. imbricata) are distinguished from Scaphyglottis by small, almost entirely red flowers, with nearly equal perianth segments. It is the only group pollinated by hummingbirds.^[19]

The vegetative morphology is similar to Scaphyglottis. The pseudobulbs are typically cylindrical or fusiform, bear deciduous linear-lanceolate leaves, and grow one from at the apex of another to form articulated chains. The racemose inflorescence is apical or from the nodes of the joints between pseudobulbs, with few flowers open simultaneously (generally only two or three) being produced over several years.

The red or orange flowers have lanceolate sepals and petals. The labellum is simple and folded down, the same color as the other perianth segments. In some species (e.g., H. bidentata) there is a bright yellow callus in the form of two teeth near the base of the labellum. The pollinarium contains four pollinia.

According to the rules of the International Code of Botanical Nomenclature, Hexisea is the name that should be used for all Scaphyglottis, because the name Hexisea (for one of these species) was published before Scaphyglottis. However, Dressler suggested that the name Scaphyglottis be retained to avoid changing the names of a large number of well known species.,^[20] and that the formally correct name Hexisea be used only when referring to those species which had been traditionally known as Hexisea. On the strength of this recommendation, Kew has made Scaphyglottis the accepted name, and reduced the correct name Hexisea to synonymy.^[21]

Euothonaea was published by Reichenbach in 1852, but was invalid for technical reasons^[22] This genus has always been relegated to synonomy under Hexisea.

• Euothonea oppositifolia (A.Rich. & Galeotti) Rchb.f. (1852) was previously published as Epidendrum oppositifoliium A.Rich. & Galeotti (1854). In 1850, it was published as Diothonea oppositifolia (A.Rich. & Galeotti) Rchb.f. and in 1862 as Hexisea oppositifolia (A.Rich. & Galeotti) Rchb.f. In 2002, Dressler reduced it to synonymy under Hexisea imbricata by publishing the name Scaphpyglottis imbricata.

Costaricaea was erected by Schlechter in 1923 for Costaricaea amparoana,^[23] which was moved to Hexisea amparoana in 1934 ^[24] and then to Scaphyglottis amparoana in 1964.^[25]

Platyglottis was proposed in 1942 by Louis Otto Williams for the new Panamanian species Platyglottis coriacea.^[26] In 2004, Dressler transferred it to Scaphyglottis coriaceae.^[27] Although the pseudobulbs of this species grow from the apices of previous pseudobulbs like the rest of the genus Scaphyglottis, this species differs by having wide. flat, coriaceous, alternate leaves, and an apical racemose inflorescence with up to four pale flowers open at once, featuring long ovaries and large bracts at the base of the peduncle. Both the vegetative and floral morphology make this species easy to distinguish for the other species of Scaphyglottis.

Helleriella. In 1974 Garay and Sweet transferred Scaphyglottis punctulata (Reichenbach f.) C. Schweinfurth,^[28] (Ponera punctulata Reichenbach f., Epidendrum dussii Cogniaux) to the Andean genus Helleriella without any explanation. A comparison of S. punctulata with the two species of Helleriella shows that it fits poorly into that genus. Except for a somewhat unusual habit it is a typical Scaphyglottis. This is also confirmed by molecular data.

Subtaxa

A study of inner transcribed spacer data has suggested that the illegitimate name Pachystele Schltr. (1923) corresponds to a well-supported clade distinct from the remainder of the modern concept of Scaphyglottis, as does the species S. livida.^[29] The authors of the study noted that this "Pachystele clade" corresponds roughly to Hexisea sensu lato:

• S. amparoana
• S. arctata
• S. bidentata
• S. chlorantha
• S. confusa
• S. cuniculata
• S. corallorrhiza
• S. densa
• S. fasciculata
• S. gentryi
• S. gigantea
• S. imbricata
• S. jimenezii
• S. reflexa
• S. sigmoidea

The paper did not publish any names for these three suggested sub-taxa of Scaphyglottis, but did publish three new combinations.

Species