Vanilla dressleri Soto Arenas (2010: 303)

Damián-Parizaca, Alexander & Mitidieri-Rivera, Nicole, 2023, Vanilla cameroniana (Orchidaceae, Vanilloideae), a new species from French Guiana and new records from the Guiana Shield, Phytotaxa 609 (3), pp. 222-232 : 229

2. Vanilla dressleri Soto Arenas (2010: 303) ( Figure 5 G, H )

Type:— PANAMA. Colón: end of Pipeline Road on Río Agua Salud , 20–50 m, 15 April 1982, S . Knapp & J . Mallet 4621 (holotype: MO3032052 !) .

Distribution:— Panama, Costa Rica, Colombia, Venezuela, French Guiana ( Figure 4 ).

Taxonomic Discussion:—This species is part of a group that includes Vanilla cribbiana Soto Arenas (2010: 300) , Vanilla hostmanni Rolfe (1896: 462) , and V. corinnae . These species feature long inflorescences with a densely papillose rachis and sepals, and yellowish to orange flowers. What sets V. dressleri species apart is the sub-rhombic lip, which is unlobed and has flat, minutely papillose veins. While initially thought to be restricted to Costa Rica, Panama and Colombia, the distribution is here expanded to include Venezuela and French Guiana.

The French Guiana specimen cited here (Cremers et al. 13016) was identified as Vanilla porteresiana Veyret & Szlach. (1995: 219) by Szlachetko (2016). However, we concur with Soto Arenas & Dressler’s (2010) assessment that V. porteresiana is based on an immature flower of V. hostmanni . The wide dorsal keel on the petals depicted for V. porteresiana ( Figure 1 in Szlachetko & Veyret 1995) is characteristic of the immature petals of V. hostmanni , whereas in mature flowers the keel becomes slimmer. We have compared immature flowers (3 cm long) of V. hostmanni from Peruvian material with the drawings provided for V. porteresiana and found no significant differences. Additionally, we were unable to distinguish V. barrereana Veyret & Szlach. (1995: 2020) which appears to be based on mature flowers as evidenced by its narrow dorsal petal keel and larger size, from any Peruvian, Ecuadorian, or Brazilian specimens of V. hostmannii that we examined. Even though V. hostmannii and V. dressleri share features, such as the papillose external sepals and thickened veins in the lip, they can be easily differentiated by their lip morphology. V. hostmannii has a clearly trilobed lip, while V. dressleri has a sub-rhombic lip shape.

Specimens examined:— VENEZUELA. Amazonas: Along river just below mouth of Rio Cunucunuma , 20 June 1959, J. J . Wurdack & L. S . Adderley 43074 [flower] ( US 00319616, NY 04170449 ) . FRENCH GUIANA. Saint-Laurentdu-Maroni: Layon Eaux Claires-Region de Saul , 53 12’, 3 37’, 250 m, 16 February 1993, Cremers G ., Granville J . & Mori S. A . 13016 [flower] ( NY04170422 ) .

Figures

FIGURE 1. Line drawingof Vanilla cameronianabased on the FrenchGuiana holotype.A.Habit.B. Leaf adaxial surface.C. Inflorescence. D. Flower, E. Dissected perianth. F. Lip. G. Pubescent detail at the base of the lip. H. Penicillate callus. I. Detail of the lip apex. J. Anther. K. Column with and without anther. Drawing by N. Mitidieri based on A, D iNaturalist record and B, C, E–K Sabatier D. & Prevost M.-F 4912 (SEL).

FIGURE 4. Geographic distribution of the species discussed in this study, including the limits of the Guiana Shield. The black-colored datapoints on the map represent occurrences documented in the GBIF database, while the blue-colored datapoints indicate new records reported in this study. Additionally, red datapoints represent the newly described species. The asterisk (*) is used to indicate type material.

FIGURE 5. New Vanilla records from the Guiana Shield based on herbarium material. A–F Vanilla sprucei, A–B. perianth dissection, C–D. labellum apex, E–F. column apex and anther. G–H. Vanilla dressleri, I. Vanilla corinnae. Based on Redden 2518, US (A,C,E); Redden 1843, US (B,D,F); Cremers 13016, NY (G); Wurdack 43074, US (H); and Wurdack 43170, US (I). Photographs by A. Damián.