Ascogrammitis pichinchensis (Hieron.) Sundue

Authority

Sundue, Michael A. 2010. A monograph of , a new genus of grammitid ferns (Polypodiaceae). Brittonia. 62 (4): 357-399.

Family

Polypodiaceae

Scientific Name

Ascogrammitis pichinchensis (Hieron.) Sundue

Description

Description - Plants epiphytic, singular or forming small colonies, sometimes epipetric or on soil banks; roots non-proliferous; rhizome 0.4- 0.6 mm wide; branch buds absent; rhizome scales 1.5-2.5 x 0.3-0.4 mm, lanceolate, clathrate, the cell walls black, the lumina clear, sometimes the lumina very narrow and so appearing occluded, the margin sparsely setose, the setae 0.2 mm long, the apex attenuate, the surface glabrous; fronds 6-36 x 0.6-1.7 cm, hemidimorphic, pendent, usually bearing the mycelia and ascomes of Acrospermum; petioles 1.5-4.5 cm x 0.2- 0.4 mm, with a single vascular bundle, castaneous, terete, non-marginate, moderately setose, the setae 1.5-2 mm long, sparsely hairy, the hairs 1 -furcate; rachises with castaneous sclerenchyma visible on both the abaxial and adaxial sides of the lamina, or the sclerenchyma not visible on the adaxial side, moderately setose, the setae 1.5-2 mm long, sparsely hairy, the hairs 1 -furcate; laminae membranaceous, deeply 1-pinnatifid to 1-pinnate, nearly linear, even sided, with 21-85 pairs of segments; medial segments 3-9 x 1.8-3.5 mm, oblong, slightly ascending, the base decurrent, the apex rounded, the margin slightly undulate, setose, the setae 0.5-1 mm long, the abaxial and adaxial lamina surfaces moderately setose, the setae 0.5-1 mm long, fertile portions of the lamina more densely setose than sterile portions; segment costae with the dark sclerenchyma sometimes visible abaxially, not readily visi- ble adaxially; veins not readily visible on either side of the lamina; hydathodes cretaceous; sori inframedial, confined to distal portions of the frond, 3-4 pairs per segment; receptacular setae present.

Discussion

Distribution - The Western Cordillera of northern and central Ecuador; (2800-)3000- 3500(-3700) m. Fay & Fay 3105, 3113, 3285, report elevations of 1900 m, 1000 m lower than any other record. Whether this represents a labeling error or a disjunct population is unclear. No other collections of A. pichinchensis have been made at that locality, the Rio Guaj alito Reserve, despite it being frequently visited by collectors.

Ascogrammitis pichinchensis is distin- guished by its membranaceous laminae, rounded segments, and setae present along segment margins and on both sides of the laminae. Like its congeners, the costae are provided with dark sclerenchyma, but in A. pichinchensis the costae are obscured beneath a layer of parenchyma and therefore not clearly visible on the lower surface of the frond.