Specklinia pertenuis (C. Schweinf.) Karremans & Gravend., 2015

Karremans, Adam P., Bogarín, Diego, Pupulin, Franco, Luer, Carlyle A. & Gravendeel, Barbara, 2015, The glandulous Specklinia: morphological convergence versus phylogenetic divergence, Phytotaxa 218 (2), pp. 101-127 : 116-119

Specklinia pertenuis (C. Schweinf.) Karremans & Gravend. , comb. nov.

Basionym: Pleurothallis pertenuis Schweinfurth (1935: 83) .

Type :— GUYANA. Essequibo River , Moraballi Creek, near Bartica, nearly at sea-level. 15 September 1929, N. Y. Sandwith 304 (holotype, K!; isotype, AMES; illustration of type, AMES!) .

Epiphytic, caespitose, ascending, erect herb. Roots fibrous, flexuous, glabrous, to 1 mm in diameter. Stem abbreviated, terete, to 3.7 mm long, completely concealed by two papyraceous, subancipitous, acute sheaths. Leaf narrowly linear or oblanceolate-linear, coriaceous, fleshy, up to 22 × 1.7 mm, minutely and irregularly emarginate at apex, the mid-vein protruding abaxially into a small apicule, gradually tapering toward the base into a deeply conduplicate petiole, subcoriaceous. Inflorescence slender, successively single flowered, in anthesis shortly surpassing the leaves, minutely puberulent. Floral bracts infundibuliform, puberulent. Pedicel conspicuously protruding beyond the floral bract. Ovary slenderly terete, muricate. Flower buds brownish orange. Dorsal sepal lanceolate, 3-veined, acute, concave, 4 × 1.8 mm; lateral sepals elliptic-ovate, 3-veined, 4.1 × 2.2 mm, connate for about half of their length. Petals asymmetrical, oblong-spatulate, 2.7 × 1 mm, 1-veined. Lip sagittate-oblong, with acute, spreading angles just below the middle, 3 × 1.4 mm, rounded at the apex, finely papillose on the upper surface. Column stout, 2 mm long, narrowly winged on each side. * NOTE: Description is adapted from the original protologue.

Additional materials: — BRAZIL. Estado do Pará, Município de São Felix do Xingu, vila Canaã , fazenda do Sr. Josué, 4 January 1997, Silva 630 ( MG!) . GUYANA. Roriabo , 7 November 1894, im Thurn 84 ( K; photograph of type, AMES!) ; Aruka , June 1897, im Thurn 84 ( K; photograph of type, AMES!) ; B.- B. [Barima-Barama] Road. November 1896, im Thurn 84 ( K; photograph of type, AMES!) between Mazaruni Station and Labbakabra Creek, 27 April 1937, Sandwith 1225 ( K) ; Pomeroon River , March 1884, Jenman 1996 ( K) ; Upper Mazaruni District , adjacent to Eboropu Mountain, alt. 470 m, 8 April 1979, Edwards 1188 ( K) . SURINAME. Brownsberg Mazaroni top, 16 April 1981, Determann 148 ( SEL!). Wilhelmina Mts., 15 July 1981, Determann 81-2168, flowered in cultivation 14 February 1982, Luer 6829 (illustration, SEL!). Lely Mountains, distr. Marowikne, 1 June 1976, Teunissen & Teunissen 1631 ( SEL!) . VENEZUELA. 113 km south of El Dorado , in fairly dense forest at about 600 m, Dunsterville 430 (illustration, AMES!; Fig. 11 ) .

Etymology: —The name comes from the Latin tenuis meaning “thin or fine”, referring to the “very slender” plants.

Distribution: —Known from Venezuela, Guyana, Suriname and Brazil, where it is typically found growing at low elevations, from around sea level to up to 600 m ( Fig. 6 ).

Notes: —When describing Specklinia pertenuis (as Pleurothallis pertenuis ), Schweinfurth recognized it closely resembled P. vittariifolia (= Specklinia vittariifolia ). He distinguished the two species apart on the basis of the glabrous sepals of the first, which are characteristic of the second. Illustrations by Dunsterville and Luer of material from Venezuela and Suriname, respectively, show flowers with less conspicuous ornamentation than observed in S. glandulosa and S. vittariifolia , but nonetheless present. It is possible that the inconspicuous ornamentation of Schweinfurth’s plants was even more difficult to observe in herbarium material. The disposition of the floral parts in the illustration and the statement in the protologue that “bud brownish orange”, suggests that the type illustration was prepared from a cleistogamous flower. In fact, ovaries are swollen in many flowers of the herbarium specimens and illustrations.

Material from Brazil, Guyana, Surinam and Venezuela is therefore recognized a distinct species under the name Specklinia pertenuis . It can be recognized by the inflorescence that barely exceeds the leaf, and is rarely multi-flowered, the frequently bears cleistogamous flowers, with inconspicuous sepal ornamentation, very narrow sepals and petals, and a lip with sharp-triangular spreading angles just below the middle.

The plant illustrated by Silva & Silva (1997) of Brazilian origin (Silva 369; MG!) shows perianth parts typical of the S. glandulosa group, and comparable to those of S. pertenuis particularly. Nevertheless the leaves are much broader and have a different shape. Another Brazilian collection (Silva 630; MG!) does overlap well with S. pertenuis . Both specimens come from Sao Felix do Xingu, and at first glance do not seem to be the same species. Without more material it is difficult to determine them with certainty.

Figures

FIGURE 6. General distribution map of the glandulous species of Specklinia. Edited by D. Bogarín.

FIGURE 11. Illustration of Specklinia pertenuis (C.Schweinf.) Karremans & Gravend by G.C.K. Dunsterville, based on Dunsterville 430 (AMES) from Venezuela. Reproduced with the kind permission of the Orchid Herbarium of Oakes Ames, the Harvard University Herbaria.