Specklinia macayensis A.Doucette, 2016

Doucette, Alfonso, Timyan, Joel, Henrys, Ingrid & Cameron, Kenneth M., 2016, A tiny new species of Specklinia from Haiti’s Parc National Naturel Macaya and new combinations in Acianthera (Pleurothallidinae, Epidendreae, Epidendroideae, Orchidaceae), Phytotaxa 275 (3), pp. 263-276 : 267

Specklinia macayensis A.Doucette sp. nov. ( Figs. 2–3 )

Type :— HAITI. Sud: Pic Macaya National Park, secondary forest on karst, 1,000 m, 25 May 2016, Doucette 336 (holotype: WIS; isotype: USD) .

Diagnosis: The new species is similar to Specklinia wrightii but differs morphologically in the repent ( v. subrepent to caespitose) growth habit, the apiculate sepals, obtuse (v. acuminate-truncate) apex of the lip, lacking globular calli on the column-foot, and the entire ( v. erose ) margin of the apex of the column, and molecularly based on a unique ITS sequence.

Epiphytic, repent herbs, roots 0.4 mm in diam. Stems erect, terete, 1.4–2.3 × 0.4 mm, enveloped by 2–3 tubular, papery sheaths, 1.0–2.0 × 0.5 mm. Leaves petiolate, elliptical, fleshy, tridenticulate at the apex, sparsely covered by minute bumps adaxially, smooth abaxially, 6.0–7.7 × 2.1–3.2 mm. Inflorescence a successively two-flowered raceme; peduncle filiform, glabrous, ascending, 1.1–2.4 × 0.1 mm; bracts tubular, membranous, 1.1 × 0.4 mm; pedicel filiform, glabrous, 1.4 × 0.1 mm; ovary terete, glabrous, 6-sulcate, 0.7 × 0.1 mm; dorsal sepal purple, membranous, elliptical, apiculate, glabrous, weakly carinate, 10.0 × 2.5 mm; lateral sepals purple, membranous, elliptical, sub-falcate, apiculate, connate from the base to before the middle, forming a shallow mentum below the column-foot, 3.0–4.0 × 1.2–1.5 mm; petals membranous, narrowly elliptical, translucent purple with a darker purple midvein, 7.0 × 1.0 mm; lip dark purple, fleshy, oblong, with a shallow channel along the middle, truncate base,1.5–1.6 × 0.5 mm; column 1.4 × 0.5 mm.

Etymology:—From “Macaya”, the type locality, and the Latin suffix -ensis denoting a toponym.

Distribution:— Specklinia macayensis is apparently endemic to Haiti. The only other collection of the species known is a specimen housed at SEL, which was identified as S. lichenicola, D. Dod 2-F! ( SEL), but actually conforms to the new species. As such, S. lichenicola is excluded from the flora of Haiti as erroneously reported by Ackerman (2014).

Notes:—According to Stenzel (2004), Specklinia lichenicola (= Pleurothallis lichenicola ) is considered a synonym of Specklinia wrightii (= Pleurothallis wrightii ) and Pleurothallis gemina Stenzel (2001: 28) represents a distinct species. On the other hand, Luer (2006) considered Specklinia lichenicola and S. wrightii separate species and recognized P. gemina as a synonym of P. lichenicola . In the rest of this article we have arbitrarily followed Luer (2006), although the S. lichenicola DNA sequence generated by Stenzel was based on an individual that matches Pleurothallis gemina morphologically. The correct taxonomic treatment of these three concepts ( P. gemina , S. lichenicola , and S. wrightii ) is unresolved and warrants deeper investigation.

Our careful investigation of the type material revealed the possibility that all three concepts represent a single polymorphic species. A Pleurothallis lichenicola isotype ( C.Wright 1507, PH!) includes two flowers that appear to have white sepals “suffused with red at the thickened tips” as described by Luer (2006) and a purple lip, which is intermediate between the all purple flowers of S. wrightii and the all white flowers of P. gemina . Stenzel (2001; Stenzel 760, HAJB) observed an intermediate individual with white sepals and a red-purple lip that he hypothesized to be a hybrid between the P. gemina and S. wrightii . Although not definitive, the identical ITS sequences ( Stenzel 2004) support the recognition of P. gemina (two white flowers) and S. wrightii (one purple flower) as two morphological extremes of a single species. We feel the situation should be investigated further, but treat the three taxa as separate species for the sake of distinguishing our new, Haitian species from all three Cuban concepts.

Specklinia macayensis is most similar to Specklinia wrightii but can be distinguished by the repent ( v. subrepent to caespitose) growth habit, the apiculate sepals, obtuse (v. acuminate-truncate) apex of the lip, lacking globular calli on the column-foot, and the entire ( v. erose ) margin of the apex of the column, and molecularly based on a unique ITS sequence. Specklinia macayensis is also similar to Pleurothallis gemina from which it can be distinguished by the repent ( v. subrepent ) habit, successively ( v. simultaneously ) flowered raceme, the purple ( v. white or cream colored) sepals, and the purple ( v. white ) lip, and molecularly based on a unique ITS sequence. The Pleurothallis gemina and S. wrightii ITS sequences generated by Stenzel (2004) are identical. Both sequences differ from the Specklinia macayensis ITS sequence by eight point mutations at: 37 (G→A), 38 (A→G), 107 (G→T), 127 (C→T), 143 (G→ T), 451 (A→G), 482 (A→G), 483 (G→A). The base pair positions correspond to those provided by Stenzel (2004). Specklinia macayensis can be distinguished from S. lichenicola by the repent ( v. subrepent to caespitose), purple ( v. white or white suffused with red at the thickened tips) sepals, and the apiculate (v. non-apiculate) sepals.

Figures

FIGURE 2. Specklinia macayensis.A. Habit, drawn to 1 cm scale. B. Flower. C. Dorsal sepal. D. Lateral sepals. E. Petal. F. Lip. G. Flower with petals and sepals removed. B–G drawn to 1mm scale. Drawn from the holotype.

FIGURE 3. Specklinia macayensis in situ at Parc National Naturel Macaya.