Maxillaria dichaeoides 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 : 26

Maxillaria dichaeoides Bennett & Christenson , sp. nov. ( Fig. 4 )

Species haec Maxillaria ponerantha Reichenbach (1854: 17) similis sed floribus atropurpureis, petalis trinervis, labello acalloso, anthera non papillosa differt.

Type:— PERU: San Martín: Along the road in Nieva, D. Bennett 8027 (holotype: HAO) .

Mat-forming epiphytes. Pseudobulbs ellipsoid, compressed, to 1.5× 0.5 cm, separated by rhizome segments of varying length, the rhizomes sheathed with foliaceous bracts subsimilar but slightly smaller than the leaves. Leaves 1–2, 1 being more common, oblong, conduplicate at the base, obliquely bilobed at the apex, 1.7× 0.5 cm. Inflorescences subsessile from the axil of sheaths on the developing rhizome. Flowers solitary, not opening widely, intense dark purple. Dorsal sepal elliptic, obtuse, concave, 8× 3.1 mm, the lateral sepals obliquely broadly ovate, obtuse, 8× 3.5 mm. Petals elliptic from a cuneate base, obtuse, 3-nerved, 7× 3 mm. Labellum unlobed, elliptic with low involute lateral margins, truncate-emarginate, very glossy, 7.7× 3.6 mm, without a callus. Column arching, slightly dilated toward the apex, 5.5× 2 mm long; the anther transverse, minutely verruculose; the pollinia 4, suborbicular, in two tightly appressed pairs. Flowering from August to September but probably throughout the year as growths mature.

Habitat:—Wet montane forest.

Distribution:—At least Ecuador and Peru. Dodson and Dodson’s (1980: pl. 153) record for M. foliosa Ames & Schweinfurth (1925: 60) in Ecuador is M. dichaeoides . The specimen has a labellum without callus.

Etymology:—Named for the remarkable resemblance of the plants to the orchid genus Dichaea .

Observations:—This species is distinguished by the Dichaea -like growth habit, intensely dark purple flowers, the labellum without callus, and the unadorned anther. It is most closely related to M. ponerantha Reichenbach (1854: 17) a species with predominately yellow flowers, a well-defined callus, and an anther with a papillose dorsal ridge. It is also similar to M. caucae Garay (1967: 258) , a species with dark brown flowers, but that species has a well-defined callus and 5-nerved sepals.

Figures

FIGURE 4. Maxillaria dichaeoides Bennett & Christenson (drawn from Bennett 8027 by M. Alcántara A.). A. plant in flower; B. flower, side view; C. column and labellum, side view; D. sepals and petals, dissected; E. labellum, from above; F. column, +/- undersurface; G. anther, ventral view (left), dorsal view (right); H. pollinia, ventral view (left), dorsal view (right).