Encyclia dichroma (Lindl.) Schlechter (1914: 209)

Bastos, Cláudia A., Meneguzzo, Thiago E. C. & Berg, Cássio Van Den, 2018, A taxonomic revision of the Brazilian species of Encyclia (Orchidaceae: Epidendroideae: Epidendreae), Phytotaxa 342 (1), pp. 448-450 : 448-450

14. Encyclia dichroma (Lindl.) Schlechter (1914: 209) . Basionym: Epidendrum dichromum Lindley (1843: 78) . Type:— BRAZIL. Pernambuco: no locality, 3 October, Quesnel s.n. (holotype: K 293885!) ( Figs. 11 , 25A ).

Homotypic synonym:

Encyclia dichroma (Lindl.) Porto & Brade (1935: 29), nom. superfl.

Heterotypic synonym:

Epidendrum roseum Gerard (1848: 265) . Type:— BRAZIL. Bahia: no locality, 1847, Porte s.n. (holotype: P, not found; lectotype designated by Bastos et al. (2016): watercolour illustration in Gerard (1848: 266).

Terrestrial and epiphytic herbs, 16.8−21.2 cm tall. Pseudobulbs conical, 6.2−7.5 × 0.9−1.5 cm. Leaves 1−2, oblong to oblanceolate, 10.6−14.0 × 0.9−1.2 cm, apex obtuse to acute. Inflorescence a 6−11-flowered, simple raceme; peduncle 16.2−36.6 cm long; rachis 10.5−18.7 cm long. Flowers with pedicel 2.7 × 0.3 cm, warty; sepals pink, dorsal lanceolate, 2.6 × 0.6 cm, laterals lanceolate, 2.7 × 0.6 cm, erect, margin entire, apex acute; petals pink, spatulate, 2.6 × 1.3 cm, erect, margin undulate, apex mucronate; lip with claw 0.5 × 0.2 cm, lateral lobes free relative to the midlobe, 1.2 × 0.7 cm, pink, at a ˂ 45° angles to midlobe (in the flattened lip), not overlapping it, margin entire, apex obtuse, midlobe spatulate, 1.0 × 1.0 cm, pink with white border, sinuous, margin undulate, apex obtuse, callus cymbiform, truncate; column clavate, c. 1.3 × 0.4 cm, clinandrium apex tridentate, lateral teeth horn-like, apex premorse, column arms elliptic, 0.20 × 0.15 cm, apex obtuse; stigma elliptic, with basal hooks; anther one, yellowish.

Distribution and habitat:— Endemic to the Atlantic Forest in the Northeast ( Fig. 10 ).

Etymology:— From the greek prefix di-, two and chroma, colour, refering to the difference in colour between the dark pink lip and light pink petals and sepals in the original material.

Phenology:— Flowering all year.

Taxonomic notes:— Encyclia dichroma is similar to E. jenischiana , but differs mainly in its narrower lip midlobe (ca. 1 cm wide in E. dichroma and ca. 1.5 cm wide in E. jenischiana ) and more elongate claw (0.5 cm long in E. dichroma and 0.3 cm long in E. jenischiana ). Besides this, E. dichroma is more commonly found in restinga, as a terrestrial in sand or epiphtic in shrubs, whereas E. jenischiana occurs at higher elevation and is generally rupicolous. Because of the great morphological similarity, Almeida (2009) studied the species delimitation for this pair using genetic and morphological data as well as mycorrhizal association and concluded that E. dichroma and E. jenischiana (in that study as E. ghillanyi Pabst 1976: 80 ) represent distinct species. The phylogenetic analysis of the associated fungi based on nrITS indicated distinctineness of both species, E. dichroma being associated with a single fungus, whereas E. jenischiana is a generalist. The author related this to the differing habitats, hypothesising that a rupicolous plant like E. jenischiana requires a less specific mycorrhizal association to survive in a hostile environment. Morphometric results also supported separation of the two species with no overlap of invididuals, and genetic data (ISSRs) indicated two distinct, albeit closely, related species. Based on this, Almeida (2009) postulated incipient speciation between E. dichroma and E. jenischiana , allied to the paucity of morphological diagnostic characters to separate the species, which nevertheless are distinct in a multivariate assessment. Epidendrum roseum was recently synonymised under E. dichroma based on the illustration in the original description (which serves as lectotype) and distribution (Bastos et al. 2016).

Selected specimens exmined: BRAZIL. Bahia: Belmonte, Belmonte− Petrolândia road, 16 July 2007, Almeida & van den Berg 5 ( HUEFS) ; Camaçari, Arembepe , 2 January 1998, Carvalho 1 ( HRB) ; Canavieiras , 28 June 1966, Belém & Pinheiro 2426 ( HB, IAN, UB) ; Gandu, May 1962, Gurgel s.n. ( ESA 14977 ) ; Itacaré, Ilhéus− Itacaré road, 25 June 1998, Silva et al. 3826 ( CEPEC) ; Salvador, Estela Mares , 23 February 1998, Nascimento & Costa 52 ( HRB) ; Santa Luzia, Piatã Mirim , 28 July 2006, Almeida & van den Berg 3 ( HUEFS) . Pernambuco: no locality, 1897, Weathers s.n. ( BM 99233 ) . Sergipe: Areia Branca, ecological station at Serra de Itabaiana , 200−300 m, 23 January, Monteiro et al. 6486 ( GUA) .

Figures

FIGURE 10. Distribution in Brazil of Encyclia cyperifolia, E. dichroma, E. duveenii, E. fimbriata, E. fowlie and E. gallopavina.

FIGURE 11. A−D. Encyclia cyperifolia. A. Dorsal sepal. B. Lateral sepals. C. Petal. D. Lip (sin collector, ESA 5268). E−K. Encyclia dichroma. E. Dorsal sepal. F. Lateral sepals. G. Petal. H. Lip. I. Detail of lip callus. J. Column front view. K. Column side view (Belém & Pinheiro 2426). L−S. Encyclia duveenii. L. Habit. M. Dorsal sepal. N. Lateral sepals. O. Petal. P. Lip. Q. Detail of lip callus. R. Column front view. S. Column side view (Pirani et al. 12470). Illustration by Carla de Lima.

FIGURE 25. A. Encyclia dichroma. B. Encyclia duveenii. C. Encyclia fimbriata. D. Encyclia fowliei. E. Encyclia gallopavina. F.Encyclia gonzalezii. G. Encyclia granitica. H. Encyclia ionosma. I. Encyclia jenischiana. J. Encyclia linearifolioides. K. Encyclia mapuerae. L. Encyclia oliveirana. (Photographers: A−B, D, F−L: C. van den Berg. C: R. V. Leitão. E: A. Peres Júnior).