Melpomene huancabambensis Lehnert

Authority

Lehnert, Marcus. 2013. Grammitid ferns (Polypodiaceae). II. . Fl. Neotrop. Monogr. 112: 1--121. (Published by NYBG Press)

Family

Polypodiaceae

Scientific Name

Melpomene huancabambensis Lehnert

Type

Type. Peru. San Martin: Prov. Rioja, Buenos Aires, rd Pedro Ruiz-Rioja, 2000 m, 05°42'09"S, 77°53'06"W, H. van der Werff, B. Gray, R. Vasquez & R. Rojas 15352 (holotype, UC; isotype, MO).

Description

Species Description - Plants epiphytic, in moss layers. Rhizomes stout, short-creeping to erect, 1.0 mm diam. Fronds to 33.5 cm long, pendent, inserted onto the rhizomes at narrow angles, fasciculate (internodes 0.2-1.0 mm). Rhizome scales 2.0-3.2 x 0.3-0.5 mm, (10—)12—14(—16) cells wide across bases, clathrate, dark brown, strongly iridescent, narrowly cordate, long-acute to attenuate at tips; apical cells 1-5, in nodding clusters or linearly arranged. Petioles (12-)45-55 mm long, 0.6-1.0 mm thick, terete, densely hairy with setiform and ciliform hairs, usually rather lax, dark brown to castaneous, (1.8-)2.0-3.5 mm long; simple and branched clavate hairs absent or very sparse. Laminae papyraceous to chartaceous, to 140-290 x 29-36 mm, narrowly elliptic (broadest at or beyond the middle), cuneate to shortly decurrent at bases, long-acute at tips. Rachises deeply dark brown to black, planar adaxially, strongly hemi-spherically protruding abaxially, strongly hairy abaxially, moderately hairy adaxially, proximally more densely hairy than distally, setiform and ciliform hairs castaneous, 1.5-3.0 mm long. Largest segments 22-28 x 3-8 mm (4-5 times longer than broad), central segments patent or nearly so (80-90°), distal segments weakly ascending (65-75°), segments equilateral at bases, fully adnate, long-deltate to oblong, the tips obtuse; midveins obscurely visible in dried specimens; proximal segment pairs markedly smaller than the following segments (1/2 to 1/3 of longest segments), sometimes the lowermost 2-5 segment pairs auriculiform; setiform hairs 1.0-2.0 mm long evenly distributed on laminae abaxially, also in sori and along midveins but not clustered here, present adaxially mainly along the midveins, always some hairs on the margins; hydathodes lacking or weakly developed in parts of a frond, small and inconspicuous. Sori 3-9 pairs per segment, (0—)1—3 setiform hairs to 1.5 mm long in them, more hairs around them on the laminae, often covering the sori.

Discussion

Melpomene huancabambensis is an ally of M. pilosissima, with which it matches in the densely hairy, terete petioles and the hairy laminae, which may have hairs along the segment margins and the adaxial surface. It is characterized by the lack or poor development of hydathodes (vs. always present and well-developed in M. pilosissima). The often large size of the plants, relatively short petioles, and the predominantly patent segments of M. huancabambensis create a habit that is quite different from that of M. pilosissima, where the petioles tend to be longer and the segments more ascending. Of the two varieties of M. pilosissima, var. pilosissima further differs in being less hairy on the segments adaxially than M. huancabambensis. Melpomene pilosissima var. tsatchelae may equal M. huancabambensis in the hairiness of the adaxial segment surfaces, but tends to have more acute segment tips, discontinuously visible midveins, and decurrently marginate petioles, all characters not present in M. huancabambensis.

Distribution

Southern Ecuador and northern Peru, in montane forests at 1900-2200 m.

Zamora-Chinchipe Ecuador South America| San Martín Peru South America|