Pabstiella hileiaensis Gutiérrez, Smidt & Toscano de Brito, 2021

Morales, Nicolás Gutiérrez, Toscano De Brito, A. L. V. & Smidt, Eric De Camargo, 2021, Pabstiella hileiaensis (Orchidaceae Pleurothallidinae), a new species from the Atlantic Rainforest in southern Bahia, Brazil, Phytotaxa 518 (1), pp. 61-68 : 62-66

Pabstiella hileiaensis Gutiérrez, Smidt & Toscano de Brito sp. nov. ( Figs. 1–4 )

Type: — BRAZIL, Bahia, São José da Vitória, flowered in cultivation in 10 May 2021, in Curitiba, Paraná, by Marcos Klingelfus, Toscano de Brito 3927 (holotype, UPCB) .

Similar to Pabstiella ezechiasi ( Hoehne 1946: 21) Luer (2007: 119) but distinguished by the elliptical leaves, yellow flowers with red to brown veins, spatulate petals, slightly cucullate at the apex, the lip verrucose at the disc and strongly papillose and somewhat reflexed at the apex, with erect lateral lobes and two, thin, submarginal, papillose, longitudinal calli.

Plant small, epiphytic, caespitose, up to 6.0– 10.5 cm including the inflorescence; roots slender, flexuous, to 0.5 mm in diameter. Ramicauls terete, erect, 6–9 mm long, enclosed by two, loose, thin, membranaceous, ribbed, apically oblique, acute sheaths. Leaves erect, elliptical-lanceolate, coriaceous, acute, apex minutely emarginate with a central mucron, 2.2–2.6 × 0.4–0.5 cm including the petiole, the base cuneate into a petiole ca. 3–5 mm. Inflorescence a slender, suberect to flexuous, successively 4–5 flowered raceme, emerging ca. 1 mm below the annulus, up to 9.5 cm, floral bracts ca. 1.3 mm long, tubular, acuminate. Pedicel 3–6 mm long. Ovary slightly curved, shallowly sulcate, ca. 1 mm long. Dorsal sepal yellow with three red to brown veins, oblong to obovate, externally with a central carinae, somewhat convex, 3-veined, the apical margins more or less recurved, minutely pubescent in the apical half, acute, 4.0–4.5 × 1.5–1.7 mm unexpanded. Lateral sepals connate ca. 2.4–3.0 mm, forming a yellow, concave synsepal, with two lateral red to brown strips, and two external carinae, with acute apices, a shallow depression in the apical third, convex towards the apex and minutely pubescent at both sides of the apical half, 4 × 2 mm unexpanded, 2.6 mm wide when expanded. Petals yellow with red to brown, spatulate, slightly asymmetrical, apex slightly cucullate, acute, 2.5 × 1.2 mm. Lip yellowish with red to brown spots, densely spotted at the apex, three-lobed, hinged to the column foot, oblong, externally slightly carinate, truncated at the base with a pair of minute lobules at the corners, the lateral lobes on the middle third, erect, with a pair of submarginal, longitudinal, papillate calli, the disc verrucose, shallowly channeled, the apical lobe densely papillose, somewhat reflexed, obtuse, 2.5 × 0.7 mm unexpanded. Column translucent yellow, whitish along the wings, slightly arcuate, terete in the basal half, the apical half with a pair of wings with irregular margins, the apex denticulate, the anther, rostellum and stigma ventral, 2.2 × 0.7 mm, the foot thick, ca. 0.5 mm long. Anther yellowish, triangular, hooded, gibbous, 0.45 × 0.5 mm, pollinarium composed of 2, yellow, obovoid, pollinia, united by a caudicle.

Additional material examined:— BRAZIL, Bahia, São José da Vitória, flowered in cultivation in 15 May 2021, in Curitiba, Paraná, Klingelfus 289 (paratype, UPCB) .

Eponymy:— Named after Hiléia Baiana, a name given to the area with megadiverse and highly endemic flora present in northern Espírito Santo and southern Bahia states.

Distribution and ecology: —The species is apparently endemic to southern Bahia, in the evergreen forest of the São José da Vitória municipality. The plant that served as a type ( Fig. 2 ) was found growing together with Stelis triangularis Barbosa Rodrigues (1882: 91) . The paratype specimen ( Fig. 3 ) was probably collected at the type locality. The morphological differences between these two individuals is remarkable, evidenced in the length of the inflorescence and the color of the flowers, from yellow with brown to yellow with red, both in sepals, petals and lip. Some degree of variation is also noticed in the length of the sepals. No specific information about the habitat is given as the holotype and paratype specimens were prepared from cultivated plants.

Discussion: — Pabstiella hileiaensis is morphologically similar to P. ezechiasi ( Fig. 4A ). The two species share the short ramicauls covered by two ribbed, membranaceous sheaths, with long racemes far surpassing the leaves, carrying successive, long pedicellate flowers with minutely pubescent sepals, the dorsal sepal oblong, somewhat convex, the three-lobed lip, truncate at the base with a pair of minute lobules at the corners, with a pair of longitudinal calli, and by the winged column with denticulated apex. Pabstiella hileiaensis can be distinguished from P. ezechiasi by the elliptical leaves (vs. obovate to ovoid), sepals yellow with claret to marron veins (vs. orange flowers with reddish veins), petals bigger in relation to the sepals, spatulate, strongly suffused with maroon, minutely cucullate at the apex (vs. obovate, completely orange, acute), the lip yellow spotted with claret to marron, oblong, verrucose at the disc, the lateral lobes high with two, thin, submarginal, papillose, longitudinal calli (vs. orange lip with reddish margins, slightly pandurate, thick in its basal half, with lower lateral lobes and two, thick, central, longitudinal calli), with the apex slightly reflexed and strongly papillose (vs. the apex straight and slightly puberulous). Pabstiella ezechiasi has mistakenly been treated as a synonym of Specklinia grobyi (Bateman ex Lindley 1835: t. 1797) Barros (1983: 110) in several botanical databases, nevertheless the placement of this species within Pabstiella is proven by molecular and morphological evidence ( Gutierrez Morales et al. 2021, Ponert et al. 2021).

Pabstiella isabelae Chiron & Ximenes Bolsanello (2012: 110) , an endemic of Espírito Santo, also has a small habit with short ramicauls, long inflorescences with long pedicellate flowers, sepals minutely pubescent, the dorsal sepal oblong with the apical margins a little recurved, the lip trilobed, verrucose, with small lobules at the base and a winged, denticulated column. But, P. hileiaensis differs in the elliptical leaves (vs. ovoid to lanceolate), the dorsal sepal with a single, central carina (vs. dorsal sepal tricarinated), the bifid synsepal with a shallow depression in the apical third, bicarinate, with acute apices (vs. completely connated sepals, 6-carinated and rounded apices), the spatulate petals without carinas, minutely cucullate at the apex (vs. lanceolate, assymetrical, tricarinate, acute), and a lip with two submarginal, papillose, longitudinal calli (vs. lip without callosities).

Pabstiella gossameri Luer & Toscano (2011: 372) , another endemic species from Bahia state, has a similar habit, with elliptical, acute leaves, the long inflorescence with long pedicellate flowers, oblong dorsal sepal, spatulate petals and oblong, bicarinate lip. It differs from P. hileiaensis in the few flowered inflorescence, carrying the single flower in a dropping pedicel, light orange sepals with brown veins, microscopically verrucose, translucent petals, lip minutely verrucose with low lateral lobes and column obscurely dentate at the apex.

Pabstiella hileiaensis , and all the species listed here, probably belong to the Pabstiella sect. Brevicaules Gutiérrez, Toscano & Smidt , composed by P. ezechiasi and P. muricatifolia Fraga & L.Kollmann (2010: 174) ( Gutierrez Morales et al. 2021). An expanded morphological circumscription of this section must include species with obovate to elliptical leaves, short ramicauls enclosed by membranaceous to paleaceous sheaths, erect, subflexuous inflorescences that exceed the leaves, flowers long pedicellate, distant along the inflorescence, shortly pubescent or papillose sepals, dorsal sepal convex, petals slightly asymetrical, acute to minutely cucullate, papillose lip with small lobules at the corners and a winged column.

Figures

FIGURE 1. Illustration of Pabstiella hileiaensis. A. Habit. B. Flower. C. Perianth. D. Ovary, column and lip, lateral view. E. Lip. F. Expanded lip. Drawing by N. Gutierrez Morales based on the plant that was used to prepare the holotype.

FIGURE 2. Lankester Composite Digital Plate (LCDP) of Pabstiella hileiaensis. A. Habit. B. Flower, lateral view. C. Perianth. D. Ovary, column and lip, lateral view. E. Lip. F. Column, ventral view. G. Anther and pollinarium. Photographs by N. Gutierrez Morales based on the plant that was used to prepare the holotype.

FIGURE 3. Lankester Composite Digital Plate (LCDP) of Pabstiella hileiaensis. A. Habit. B. Flower, lateral view. C. Perianth. D. Ovary, column and lip, lateral view. E. Lip. F. Expanded lip. G. Column, ventral view. H. Anther and pollinarium. Photographs by N. Gutierrez Morales based on the plant that was used to prepare the paratype.

FIGURE 4. Floral comparisson. A. Pabstiella ezechiasi. B. Pabstiella hileiaensis. Photographs by Wade Collier (A) and N. Gutierrez Morales (B).