Pabstiella elegans J.Ponert, M.Portilla & Karremans, 2021

Ponert, Jan, Andrade, Mario Portilla, Karremans, Adam P., Chumová, Zuzana & Trávníček, Pavel, 2021, A new species of Pabstiella (Pleurothallidinae, Orchidaceae) from Ecuador, Phytotaxa 500 (2), pp. 108-116 : 111-113

Pabstiella elegans J.Ponert, M.Portilla & Karremans , spec. nov. ( Figs 1–2 )

Type:— ECUADOR. Azuay: west of Chaucha, 300 m, originally collected by M. Portilla in Ecuador , cultivated in Prague Botanical Garden , Czech Republic , 15 August 2019, Ponert 1273 (holotype: PRC-spirit!)

The new species resembles Pabstiella aryter , but differs in the much larger flower, with sepals that are significantly longer in proportion to the lip and petals (sepals more than three to four times the length of the lip vs. about twice the length), the narrowly lanceolate dorsal sepal is 15–17 mm long (vs. oblong, 9–10 mm long), glabrous (vs. cellularspiculate adaxially), the synsepal 18–20 mm long (vs. 9.0– 11.5 mm long) and a conspicuously glandular-echinate lip (vs. minutely spiculate).

Sympodial, epiphytic herbs, 2–5 cm tall with roots less than 0.5 mm in diameter. Rhizome repent, 1.0– 1.5 mm in diameter, 2–7 mm between ramicauls, enclosed by 1–2 dry sheaths. Ramicauls stout, suberect, 0.5–2.0 mm long, enclosed by 1–2 dry sheaths. Leaves green, 10–25 × 9–15 mm, suberect to reclining, broadly elliptical to oval, emarginate, shortly mucronate inside the notch, attenuate into 1–2 mm long petiole-like base. Inflorescence green, successively 1–2-flowered raceme, suberect to pendent, emerging from ramicaul at various distance from the apex; peduncle 1–3 cm long, pedicel 4–6 mm long, floral bract small, 2–3 mm long, adpressed, brown; ovary pale green with dark red dots, 2–3 mm long. Flower non-resupinate, erect. Dorsal sepal glabrous, creamy white with red dots (the hue varies between dark red to red-violet), 15–17 × 3 mm, narrowly lanceolate, acute, longitudinally concave basally, reflexed in the middle and towards the apex, with 3 inconspicuous veins. Lateral sepals fused almost completely to form a synsepal. Synsepal creamy white, white basally, with irregular red dots abaxially and less intensive dots adaxially, 18–20 × 10–11 mm (flattened), oblong to oval, concave, minutely bifid at the tip, cellular adaxially, glabrous abaxially. Petals translucent white with deep purple dots, 4.0 × 1.5 mm, cuneate, with 2 to 3 acute apices, glabrous, triveined. Lip ochre to pale yellow, 4.5 × 2.9 mm, obcuneate, apex broadly obtuse, conspicuously glandular-echinate, disc with two longitudinal minutely spiculate calli, the base hinged to the column foot. Column white with deep purple dots, creamy white basally, 4.6–4.8 × 1.8 mm, with column wings in apical two thirds; anther ventral; stigma ventral, column foot creamy white, 2.7 mm long; pollinarium consisting of two yellow pollinia, 0.6 mm long; anther cap yellow.

Etymology:— From the Latin for elegant, in reference to the handsome appearance of the large flowers.

Distribution and habitat:—Known only from the type locality near Chaucha in Azuay, Ecuador, where it grows epiphytically at an elevation around 300 m.

Conservation status: — To date, the species is known only from the type locality, which lies outside protected areas. This population is at risk due to deforestation. Because new localities will likely be found in poorly explored lowlands of western Ecuador, we regard P. elegans as data deficient ( DD) according to the IUCN Red List categories .

Figures

FIGURE 1. Pabstiella elegans. A. Habit. B. Leaf. C. Flower, front view (from above). D. Flower, front view. E. Flower, side view. F. Dorsal sepal, spread. G. Synsepal, spread. H. Lip, spread. I. Petal, spread. J. Column. K. Column with lip, side view. Scale bars:A–G = 1 cm; H–K = 1 mm. Drawn by J. Ponert, based on the holotype, Ponert 1273.

FIGURE 2. Pabstiella elegans. A and B. Flower, side view. C. Flower, frontal view (from above). D. Habit. E. Lip, natural shape. F. Petal. G. Column with lip, side view. H. Column, abaxial (or ventral) view. Scale bars:A–D = 1 cm; E–H = 1 mm. Photo by J. Ponert, based on the cultivated specimen of the holotype, Ponert 1273.