Palmorchis valdiviesoana Szlach. & Baranow, 2013

Szlachetko, Dariusz L. & Baranow, Przemysław, 2013, New species of Palmorchis Barb. Rodr. (Orchidaceae) from Colombia, Candollea 68 (1), pp. 105-113 : 112

5. Palmorchis valdiviesoana Szlach. & Baranow , spec. nova

( Fig. 5 ).

Typus: COLOMBIA. Vaupes: En Monfort , 29.XI.1952, Romero Castañeda 3843 (holo-: COL [ 64891 ]!).

Similar to P. guianensis , but differs in the obtriangular hypochile with basal, oblong, pubescent callus and two prominent lamellae running to the base of epichile which is ligulate-lanceolate and acute.

Plants at least 30 cm tall. Leaves petiolate; petiole and sheath 7 cm long; blade 24 cm long, 7 cm wide, oblong-elliptic, acuminate, delicate, with 7 prominent nerves. Inflorescence a raceme to 10 cm long, apical; rachis 4-5 cm long, pubescent, densely many-flowered. Flowers white, gynostemium red. Floral bracts 11 mm long, ovate-laceolate, acute, pubescent on both surfaces. Pedicel and ovary 8 mm long. Dorsal sepal 12 mm long, 2 mm wide, oblong-oblanceolate, acute, 5-nerved. Petals 11-12 mm long, 1.8 mm wide, oblong-lanceolate with a linear basal half, subfalcate, acuminate, 3-nerved, lateral nerves branching. Lateral sepals 13 mm long, 2 mm wide, oblong with lanceolate, acute apex, subfalcate, 5-nerved. Lip 13-14 mm long; hypochile 10-11 mm long, 6 mm wide, obtriangular, with a basal, woolly pubescent keel and two rather thick lamellae running along almost the entire lip length; epichile 3 mm long, 1 mm wide, ligulate-lanceolate, acute. Gynostemium 11 mm long, woolly pubescent at the base only.

Etymology. – Dedicated to Pedro Ortiz Valdivieso, an eminent Colombian orchidologist.

Ecology. – No records.

Distribution. – Collected in the Colombian departments Vaupes and probably Cundinamarca.

Notes. – This species appears to be related to P. guianensis (Schltr.) C. Schweinf. & Correll , but its hypochile is obtriangular, with a basal, oblong, pubescent callus and two prominent lamellae running to the base of epichile. The hypochile of P. guianensis is round-obovate in outline. The basal section of the lip is ventrally pubescent either side of the axis and the margins lightly ciliate; the middle nerve ventrally is gently sulcate for most of its length, dorsally quite strongly sulcate for the full length; lateral lobes obtuse to rounded.

Figures

Fig. 5. – Palmorchis valdiviesoanus Szlach. & Baranow: A. Dorsal sepal; B. Lateral sepal; C. Petal; D. Lip.