Maxillaria visseri Bennett & Christenson, 2009

Bennett Jr, David E. & Christenson, Eric A., 2009, Nine new species and one new name in Maxillaria (Orchidaceae), Phytotaxa 1, pp. 21-36 : 34

Maxillaria visseri Bennett & Christenson , sp. nov. ( Fig. 9 )

Species haec Maxillaria frechettei Bennett & Christenson (2001 : pl. 694) similis sed foliis ellipticis, ovario tuberculato, floribus coloribus, labelli medilobo transverso differt.

Type:— PERU: Amazonas: Bongara, below Venceremos Nuevo along road to Rio Nieva , 1700 m, collector Hans Visser, April 2005, D. Bennett 9079 (holotype: HAO) .

Caespitose epiphytes to 21 cm tall. Pseudobulbs ovoid, 3.3× 2 cm, subtended by a pair of foliaceous sheaths, the blades subsimilar to but shorter than the leaves, the sheath bases distichous, imbricating, to 4 cm long. Leaves 1, elliptic, attenuate to the laterally compressed petiole, obtuse, the petiole 3× 0.5 cm, the blade 15× 5.5 cm. Inflorescences several erect scapes usually shorter than the leaf, to 15 cm long, the peduncle nearly concealed by 5–6, lightly subinflated, lanceolate, graduated bracts, 2–3.3 cm long. Ovary prominently tuberculate. Flowers strongly cupped with the tepals subparallel, the sepals greenish brown tinted pale purple, the petals basal ½ opaque yellowish, apical ½ pale purple, the labellum dull yellow with a dull brownish stain across the midlobe, the column off-white. Sepals and petals elongate, slightly dilated at the base, tapered to long-acuminate tails. Dorsal sepal narrowly triangular, 5.2× 0.6 cm at the base, the lateral sepals similar but longer and broader, sigmoid, 5.3× 0.9 cm. Petals oblique, falcate, lanceolate-triangular, 4× 0.5 cm. Labellum 3- lobed, 1.4× 0.9 cm, the lateral lobes erect, semielliptic, each lobe with 4 veins, the veins twice bifurcate at their tips, lobe apices bluntly obtuse, the midlobe transverse, very short, obtuse, surface wrinkled, the disc graduated in thickness from the base to the blunt rounded thick apex, with sparsely dispersed short cilia on the outer surface, the callus oblong, obtuse-rounded, villose on the basal half. Column short, stout, arcuate, convex-lightly concave, 5 mm long, 3.7 mm wide, the clinandrium minutely denticulate, the foot lightly arcuate, adnate to the lateral sepal bases, 7 mm long; the anther helmet-shaped, central ridge rounded, tuberculate in front, 2.9× 2.2 mm; the pollinarium 2.9 mm long, the viscidium abruptly u-shaped, 1× 1.5 mm, the pollinia 4 in 2 unequal, dissimilar pairs, the outer pair larger, claviform, convex-concave, compressed dorso-ventrally, 2.2× 0.9 mm, the smaller pair obovate, nested in the concavity of the larger pair, 1.6× 0.8 mm. Flowering in April following the rainy season.

Habitat:—Wet montane forest on branches thickly covered with epiphytic mosses and lichens.

Distribution:— Peru.

Etymology:—Named for Hans Visser, a strong advocate of orchid conservation, who collected the type plant.

Observations:—Distinguished from other Maxillaria species by the tuberculate ovary, the slender elongate tepals, the elliptic contour of the 3-lobed labellum, the villose base of the labellum, and the transverse midlobe.

Figures

FIGURE 9. Maxillaria visseri Bennett & Christenson (drawn from Bennett 9079 by M. Alcántara A.). A. plant in flower; B. flower, side view; C. ovary, labellum and column, side view; D. sepals and petals, dissected; E. column and foot, undersurface (left), side view with ovary (right); F. labellum, expanded, from above; G. anther, dorsal view (left), ventral view (right); H. pollinarium, dorsal view (left), ventral view (right).