Lepanthes edwardsii Ames, Bot. Mus. Leafl.

Pupulin, Franco, 2021, A correction to the Lepanthes guatemalensis group (Orchidaceae: Pleurothallidinae) in Costa Rica, with a new species, Phytotaxa 480 (1), pp. 69-78 : 70-72

Lepanthes edwardsii Ames, Bot. Mus. Leafl. 1(4): 4. 1933.

Type:— HONDURAS. Comayagua: Pito Solo, Lake Yojoa , epiphyte in dense forest, 200 ft alt., 26 Aug 1932, J. B. Edwards 96 (holotype, AMES). Fig. 3 .

Epiphytic, small, caespitose, erect herb, to 3 cm tall. Roots thick, glabrous, to 2 mm in diameter. Ramicauls slender, 0.8-2.0 cm long, enclosed by 2-3 glabrous, whitish sheaths. Leaf thinly coriaceous, elliptic to suborbicular, slightly conduplicate, retuse, with a distinct abaxial mucro, 8-12 mm long, 5.0- 6.5 mm wide, shortly cuneate at the base into a petiole about 0.5 mm long. Inflorescence produced singly, longer than the leaf, a loose, distichous, successively flowered (to 7+ flowers) raceme to 2.5 cm long; filiform peduncle to 18 mm long, provided with 1-2 short tubular, obtuse bracts; rachis slightly fractiflex. Floral bracts broadly ovate, amplectent, subacute, ca. 1 mm long, 0.5 mm wide, sparsely muriculate. Pedicel 1.5 mm long, glabrous. Ovary 1.5 mm long, subtrigonous, smooth. Flowers resupinate, large for the genus, with pale translucent yellow sepals, faintly tinged with purple close to the margins, or purplish with a yellow tinge at base, the petals deep purple or yellow, with a faint suffusion of purple on the proximal margin of the upper lobe, the lip purple or yellow with the base suffused with red, the column and the anther cap violet-purple. Dorsal sepal broadly triangular-ovate, contracted at apex into an acuminate tail ca. 2 mm long, 8 mm long including the tail, 5 mm wide, 3-veined, connate to the lateral sepals for 2 mm. Lateral sepals narrowly ovate-lanceolate, connate for about half of their length into an ovate synsepal ca. 10 mm long (including the tails), 7 mm wide, apically contracted into acuminate tails that are straight to gently curved inward ca. 3 mm long, connate to the dorsal sepal for 2 mm. Petals transversely bilobed, 1 mm long, 2.5 mm wide, the upper lobes narrowly lanceolate-subfalcate, acute, 0.8 mm long, 2.2 mm wide, the lower lobes much smaller than the upper lobes, hemielliptic, rounded, ca. 0.7 mm long, 0.5 mm wide. Lip bi-laminate, the blades narrowly digitate-subfalcate, acuminate, straight, with an obtuse angle on the upper margin, ca. 1 mm long, 0.2 mm wide, adpressed to the column, the connectives subquadrate, the body thin, rounded-protruding at apex, with a very thin, up-curved, digitate, acute, glabrous appendix. Column short, truncate, to 1 mm long, the anther apical, bent, the stigma ventral. Anther cap cucullate, helmet-shaped, apically deeply bilobedp-retuse. Pollinia 2, narrowly linear-oblong, strongly complanate, each provided with an oblong, flattened viscidium.

Additional material examined:— COSTA RICA. No specific locality data recorded, collected by J. Loría, flowered in cultivation and prepared 4 Apr 2019, F. Pupulin 8894 (JBL-spirit!). Figs. 2A , 4 .

Interestingly, the specimen from Costa Rica shares with the Honduran type the position and orientation of the triquetrous blades of the lip, whose apices, as Ames noted in the protologue, bent down to become closely appressed to and almost touching the lateral sepals ( Ames 1933: 8). It seems that this feature is typical of the true Lepanthes edwardsii , as this orientation of the blades is absent in the species we previously discussed and illustrated from Costa Rica under that name.Apparently, the flowers of Lepanthes edwardsii may assume both a resupinate and non-resupinate orientation. Even though Blanche Ames illustrated the flowers of the type plant as regularly non-resupinate ( Fig. 1), the plants mounted on the holotype sheet ( AMES 00100585) present flowers with both kinds of orientation ( Fig. 3 ), and in most photographs of this species that we had the opportunity to observe, as well as in the living specimen we studied from Costa Rica, the flowers are always resupinate.

The plant that Luer (in Luer & Thoerle 2012: fig. 100) illustrated from Colombia under the name of Lepanthes edwardsii (Luer 11629, MO), with resupinate flowers, appears to be only distantly related to the Honduran type and could belong instead to a still undescribed taxon. The blades of lip of the Colombian specimen are thick, hemielliptic, and the appendix is broad and short, while the shape of the petals is closer to that of L. durikaensis than to L. edwardsii . Another Colombian record of Lepanthes edwardsii has been documented by Misas Urreta (2005: 280–281) from the Serranía del Baudó, a low mountain range on the Pacific coast, also with resupinate flowers, but according to the author the lobes of the lip are conical, and the illustration shows the ramicauls marginally hispid.

The discovery of a Costa Rican population of Lepanthes that can be confidently associated with L. edwardsii , leaves without a proper name the taxon that Pupulin & Bogarín (2014) discussed previously as local representative of that species. It is therefore proposed here as a species new to science with the name:

Figures

FIGURE 2. Comparison of the flower of Lepanthes edwardsii (A) and L. bogariniana (B). A, Pupulin 8894. B, Karremans 1987. Photographs by F. Pupulin.

FIGURE 3. Lepanthes edwardsii. Specimens mounted on the holotype sheet (AMES 39045 / Barcode 00100585). Note the resupinate flower on the specimen above on the right, the non-resupinate flower in the lower, right specimen, and the horizontal flower on the specimen on the lower left. Reproduced with kind permission of the Keeper, AMES Herbarium, Harvard University Herbaria.

FIGURE 4. Lepanthes edwardsii. A, habit. B, flower. C, dissected flower. D, left petal. E, lip, adaxial view. F, ovary, column and lip, lateral view. F, pollinarium, four views. G, anther cap. All drawn by F. Pupulin and S. Poltronieri from Pupulin 8894 (JBL-spirit).