Palmorchis maculata Szlach. & Baranow, 2013

Szlachetko, Dariusz L. & Baranow, Przemysław, 2013, New species of Palmorchis Barb. Rodr. (Orchidaceae) from Colombia, Candollea 68 (1), pp. 105-113 : 109

3. Palmorchis maculata Szlach. & Baranow , spec. nova

( Fig. 3 ).

Typus: COLOMBIA. Amazonas: La Pedrera Mpio, Inspección de Santa Isabel, Parque Nacional Natural Cahuinari, Estación Biológica Puerto Barbados , Varzea (rebalse baja), rodeando una laguna pequeña, dominado por Myristicaceae , periantio blanco, 1°28’S 70°46’W, 200 m., 1.XII. 1990, J. Pipoly, B. Rudas & M. Letuama 12909 (holo-: COL [ 414885 ]!).

Similar to P. lobulata , but differs in the distinctly larger flowers, subcordate, acute epichile, large, three-lobed callus, and basal part of hypochile covered with hairs. Differs from P. pabstii by the three-lobed callus on the lip.

Plants relatively small for the genus, 14-16 cm tall. Leaves 3-4, at the apex of the stem, petiolate; petiole and sheath 4- 5 cm long; blade 12 cm long, 3 cm wide, oblong-lanceolate, acute to acuminate, densely and lightly spotted on the abaxial surface. Inflorescence a raceme 3.5 cm long, apical; rachis 1.8 cm long, subdensely 8-10-flowered. Flowers rather small, white. Floral bracts 5 mm long, ovate-lanceolate, furfuraceous on both surfaces. Pedicel and ovary 6 mm long, glabrous. Dorsal sepal 9-10 mm long, 2.2 mm wide, oblong-oblanceolate, subacute, 5-nerved, the main nerve thickened outside. Petals 9-10 mm long, 2.3 mm wide, oblong-oblanceolate, subfalcate, subacute, 5-nerved, nerves branching at the apex. Lateral sepals 9-10 mm long, 2.3 mm wide, oblong-oblanceolate, subfalcate, subacute, 5-nerved, the main nerve thickened on outer surface. Lip 10-11 mm long, apically 3-lobed; hypochile 9- 10 mm long, 5.5 mm wide, the lower half oblong, pubescent and distinctly thickened along midvein, apical half almost rounded to transversely elliptic, with a thick, glabrous, 3-lobed callus at the apex; epichile 1 mm long, 0.8 mm wide, clawed, subcordate, acuminate, thickened in the centre. Gynostemium 11 mm long, slender, pubescent on the lower surface below stigma.

Etymology. – An allusion to the leaves of this species spotted on the underside.

Ecology. – Terrestrial in forest.

Distribution. – Known from Colombian Amazonas only.

Representative specimens. – COLOMBIA. Amazonas: La Pedrera Mpio, inspección de Santa Isabel . Parque pequena, dominado por Myristicaceae , perianto blanco, 1°28’S 70°46’W, 200 m, 1.XII.1990, J. Pipoly, B. Rudas, & M. Letuama 12909 ( COL!, MO).

Notes. – The diagnostic feature of P. maculata is the prominent, 3-lobed lip callus, which distinguishes it clearly from both P. lobulata and P. pabstii Veyret. Additionally , the new species differs from the former by the larger flowers, with subcordate, acute epichile and pubescent basal half of hypochile. P. maculata is the only species of the genus known to us with spotted leaves.

Figures

Fig. 3. – Palmorchis maculata Szlach. & Baranow. A. Dorsal sepal; B. Lateral sepal; C. Petal; D. Lip; E. Gynostemium; F. Floral bract. [Pipoly & al. 12909, COL] [Drawn by A. Król]