Coryanthes charlesiana Marçal & Chiron, 2022

Chiron, Guy R. & Marçal, Sidney, 2022, Coryanthes charlesiana (Stanhopeinae, Cymbidieae, Orchidaceae), a new species from Brazil, Phytotaxa 575 (2), pp. 173-178 : 175-177

Coryanthes charlesiana Marçal & Chiron sp. nov. ( Figures 1–2 )

Type:— BRAZIL. Alagoas: Atalaia, in Sitio da dona Maria da Conceição , elev. 122 m, 9° 31’ 51’’ S, 36° 03’ 33’’ W, collected on 21 May 2022, flowering in cultivation on 07 August 2022, J. dos Santos 018 ( MAC 66388 !) .

Haec species Coryanthes lanata Marçal & Chiron similis est sed plantis robustioribus cum pseudobulbis (13 cm vs. 5–6 cm longis) foliisque (50 cm vs. 26–28 cm longis) longioribus, sepalo dorsale leviter minore (2.6 × 3.2 cm vs. 3.2 × 4.0 cm), hypochilo longiore (ca. 2.8 cm vs. ca. 1.2 cm longo) cum lobo mediano elongato apice truncato (vs. breve et breviter apiculato) aliter pubescente, mesochilo longiore (3.0 cm vs. 2.0 cm longo) glabro (vs. longitudinaliter pubescente) absque secundo callo (vs. cum parvo callo prope basim), differt.

Description:—Plant cespitose; pseudobulb conical, slightly arched, ca. 13 × 2.4 cm in its broadest part, deeply 6–8- sulcate, covered at base by small membranous bracts soon dried and ruined, 2-leaved at apex. Leaf long conduplicate at base forming a pseudopetiole ca. 9 cm long, lamina narrowly elliptic, ca. 40 × 2.8 cm, with 3 main nerves. Inflorescence born at base of the new pseudobulb, pendulous, peduncle cylindrical, 17 cm long, hardly 0.2 cm diam., purple, with 3 sterile amplexicaul bracts, raceme apical, 2-flowered; floral bract ovate acuminate, pale green, ca. 2.3 × 1 cm, folded to wrap the ovary. Flower light yellow more or less wine-red spotted on the sepals, petals and mesochile and also on the inside surface of the epichile, hypochile plain with a large portion covered by white to pink hairs; pedicellate ovary cylindrical, slightly arched, sulcate, ca. 7–8 × 0.45 cm, green slightly crimson in the apical part; sepals strongly rolled on themselves, with 6 nerves on either side of the median nerve, the dorsal one transversely ovate, obtuse-acuminate, 2.6 × 3.2 cm; the lateral ones ovate oblong strongly falcate, acute to acuminate, 7 × 3.3 cm; petals ligulate, acute, 3.5 × 0.7 cm; lip 7–7.5 cm high, lip claw cylindrical, arched, 1.7 cm long; hypochile helmet-shaped with a median lobe elongate and truncate at apex, 2.8 cm long, 1.8 cm wide, 1.7 cm deep, with a broad median strip covered with 0.2–0.3 cm long hairs from just after the claw to the apex of the median lobe; mesochile gutter-shaped, geniculate in the apical third, smooth, glabrous, 3.8 cm long from its junction with the claw to the epichile, 1.25–1.4 cm wide in the wider point, furnished, just after the base, with an osmophore-bearing hump 0.8 cm high; epichile like a tapered cup, ca. 3.5 cm high, 3.6 cm wide, 3 cm deep, 3-lobed, median lobe more or less oblong, thick, 2 cm long, lateral lobes as short, acute, somewhat arched horns; column typical for the genus, straight, abruptly 90°-bent at apex, 3.8 cm long, at base with 2 fluid-producing glands 0.5–0.6 cm long, and, at apex, 2 arched horn-shaped wings 0.3 cm long, anther ca. 0.5 cm wide, 0.22 cm high, pollinia 2, subspherical, 0.125 cm diam. Fruit not seen.

Distribution and Ecology:—The taxon was first observed, in January 2019, in the surroundings of Junqueiro (Alagoas); however no material was collected. It was found again in May 2022 in the surroundings of Atalaia where only one plant could be observed. This area is located in the eastern part of the state and covered by Atlantic Forest. Pluviometry is rather high from March to August and rains are rare the rest of the year. Temperatures are rather constant, with maximum temperature from 27°C to 31–32°C and minimum temperature from 19°C to 23°C along the year. More meteorological data can be found for example on the Weather Spark (2022) web site. The type specimen was growing on a jaqueira [ Artocarpus heterophyllus Lamarck (1789: 209) ], located in a cultivated area (sugar cane) where remains of natural forest are scarce. As usual, the plant was growing in a so-called ant-garden.

Etymology:—The specific epithet is given in honour of Charles dos Santos Souza, collector’s father.

Taxonomic Discussion:— Coryanthes charlesiana is the first record of the genus in the state of Alagoas ( Meneguzzo 2022). With the above cited exception of C. speciosa , up to now the most northern Coryanthes species observed in the Atlantic Forest was C. pilosa Marçal & Chiron (2018: 138) , a member of the subgenus Lamellunguis ( Schlechter 1916: 67) Chiron & Marçal (2021: 168), found at latitude 14,5°S in the state of Bahia, i.e. ca. 700 km south to Atalaia. Coryanthes speciosa has indeed been reported from more northern areas of Atlantic Forest, however it does not belong to the pubescent group discussed here.

Compared to its closest relative C. lanata ( Figure 3 ), the clearest dissimilarities lie in the plant size, ca. 2 times bigger (pseudobulbs ca 13 cm high vs. 5–6 cm, leaves ca. 50 cm long vs. 26–28 cm); the hypochile, much longer (2.8 cm long vs. 1.5–1.7 cm) with an elongate truncate median lobe, vs. short and briefly apiculate, and differently pubescent as shown on figure 4; and the mesochile, longer, glabrous, vs. pubescent on the adaxial part, and not furnished with a second hump near the osmophore-bearing one as it is in C. lanata .

With this new taxon the Coryanthes flora in the Atlantic Forest reaches six species (four belonging to the subgenus Coryanthes and two to the subgenus Lamellunguis) and one variety, C. speciosa var. espiritosantensis Ruschi (1975: 1) ( Chiron & Marçal 2021 and personnal data).

Figures

FIGURE 1. Coryanthes charlesiana. A. Pseudobulb and leaf. B. Inflorescence. C. Flower, front and side views. D. Floral bract. E. Dorsal sepal. F. Lateral sepals. G. Petals. H. Lip, back view. I. Lip, longitudinal section. J. Hypochile, side view. K. Column, back and side views. L. Anther cap. M. Pollinarium. Drawing from type: Guy Chiron

FIGURE 2. Flower of Coryanthes charlesiana. A. Side view. B. Front view. Photographs by Joseph dos Santos, from the holotype.

FIGURE 3. Flower of Coryanthes lanata. A. Side view. B. Front view. Photographs by Sidney Marçal, from the holotype.