Taxon Details: Megalastrum masafuerae Sundue, Rouhan & R.C.Moran
Taxon Profile:
 | The Plant List |
 | International Plant Name Index |
 | Tropicos |
 | Catalogue of Life |
 | Global Biodiversity Information Facility |
 | JSTOR Types |
| JSTOR |
 | BHL |
 | Encyclopedia of Life |
 | WikiSpecies |
 | Google Scholar |
 | PubMed |
 | Morphbank |
 | IUCN |
 | National Center for Biotechnology Information |
 | Barcode of Life |
Narratives:
Family:
Dryopteridaceae (Pteridophyta)
Dryopteridaceae (Pteridophyta)
Scientific Name:
Megalastrum masafuerae Sundue, Rouhan & R.C.Moran
Megalastrum masafuerae Sundue, Rouhan & R.C.Moran
Accepted Name:
This name is currently accepted.
This name is currently accepted.
Description:
by: M. Sundue, G. Rouhan and R.C. Moran
Type: Chile. Juan Fernández Islands, Masafuera, Quebrada Vacas, on slopes of canyon among Myrceugenia, between rocks, about 60-90 cm tall, no trunk, near brook, rare, 28 Nov 1965, O. T. Solbrig, H. E. Moore Jr., & J. Walker 3676 (Holotype: GH; Isotypes: MICH, US)
Description: Plants epipetric; rhizomes not seen, reportedly not forming erect trunks; leaves ca. 1.2 m long; scales of the petiole base 1.5-2.0 × 0.20-0.35 cm, linear-lanceolate, entire, brown, lustrous, the cells isodiametric to elongate; laminae ca. 0.6 m long, 3-pinnate-pinnatifid at base, 2-pinnate-pinnatisect medially; basal pinnae 35-55 × 40 cm, inaequilateral; pinnules short-stalked to sessile, the largest pinnule of the basal pinnae 20 cm long; pinna rachises abaxially sparsely-glandular, sparsely scaly and very sparsely pubescent, the scales and hairs slightly more abundant distally, the glands short-stipitate, ca. 0.1 mm long, hyaline, the scales 3.0-4.5 × 0.5-0.6 mm, linear-lanceolate, slightly bullate, lustrous, light brown, entire, the cells elongate, the hairs 0.4-0.8 mm long, 3-6-celled, acicular, antrorse, hyaline with reddish cross-walls, the rachises adaxially non-glandular, without scales, densely pubescent, the hairs like those of the abaxial surface; costules on the abaxial surface non-glandular, sparsely pubescent and sparsely to moderately scaly, the hairs like those of the rachises, the scales 0.6-2.0 × 0.2-1.0 mm, ovate, gold-brown, translucent, slightly iridescent, the cells mostly isodiametric, the apices acute or filiform, the filiform portion up to 0.5 mm long when present, the margins erose to entire, sometimes with a few broad teeth or cilia up to 0.2 mm long, adaxially moderately pubescent, the hairs erect to spreading, otherwise similar to those of the abaxial rachises; lamina tissue between the veins abaxially and adaxially glabrous; veins visible on both sides of the lamina, the veins glabrous adaxially, abaxially the larger veins sparsely pubescent, the hairs 0.5 mm long, 4-celled, smaller veins moderately provided with 0.2-0.7 mm long, non-glandular, erect, reddish, filiform, scales, these uniseriate or rarely bifurcating; lamina margins sparsely ciliate, the hairs restricted to proximal portions of the pinnules, the hairs 0.3 mm long, 3-celled; indusia present, 0.4-0.8 mm wide, brown, often folded or lost in mature sori, the margins sparsely ciliate, the cilia 0.1 mm long, brown.
Distribution: Endemic to the Isla Masafuera (Alexander Selkirk Island) in the Juan Fernández Islands in the South Pacific Ocean, known only from the Valley of Quebrada de las Vacas.
Comments: Megalastrum masafuerae is distinguished by large indusia (0.4-0.8 mm wide) with sparsely ciliate margins, axes and veins sparsely pubescent abaxially, and nearly glabrous lamina margins with marginal hairs (if any) restricted to the proximal portions of the sinuses. Megalastrum glabrius, also endemic to Isla Masafuera, is indusiate, but its indusia are smaller (0.3-0.4 mm wide). Furthermore, it lacks hairs on the laminae and has puberulent adaxial axes. Megalastrum inaequalifolium on Isla Masatierra also has indusia, but it differs by the indusia being fugacious, smaller (ca. 0.2 mm wide), and bearing (1)5-10 erect acicular hairs, as well as by its pilose axes and evenly ciliate lamina margins that are provided with 0.5-0.7 mm long hairs.
Etymology: The specific epithet is derived from the original name given to Alexander Selkirk Island, Isla Masafuera.
by: M. Sundue, G. Rouhan and R.C. Moran
Type: Chile. Juan Fernández Islands, Masafuera, Quebrada Vacas, on slopes of canyon among Myrceugenia, between rocks, about 60-90 cm tall, no trunk, near brook, rare, 28 Nov 1965, O. T. Solbrig, H. E. Moore Jr., & J. Walker 3676 (Holotype: GH; Isotypes: MICH, US)
Description: Plants epipetric; rhizomes not seen, reportedly not forming erect trunks; leaves ca. 1.2 m long; scales of the petiole base 1.5-2.0 × 0.20-0.35 cm, linear-lanceolate, entire, brown, lustrous, the cells isodiametric to elongate; laminae ca. 0.6 m long, 3-pinnate-pinnatifid at base, 2-pinnate-pinnatisect medially; basal pinnae 35-55 × 40 cm, inaequilateral; pinnules short-stalked to sessile, the largest pinnule of the basal pinnae 20 cm long; pinna rachises abaxially sparsely-glandular, sparsely scaly and very sparsely pubescent, the scales and hairs slightly more abundant distally, the glands short-stipitate, ca. 0.1 mm long, hyaline, the scales 3.0-4.5 × 0.5-0.6 mm, linear-lanceolate, slightly bullate, lustrous, light brown, entire, the cells elongate, the hairs 0.4-0.8 mm long, 3-6-celled, acicular, antrorse, hyaline with reddish cross-walls, the rachises adaxially non-glandular, without scales, densely pubescent, the hairs like those of the abaxial surface; costules on the abaxial surface non-glandular, sparsely pubescent and sparsely to moderately scaly, the hairs like those of the rachises, the scales 0.6-2.0 × 0.2-1.0 mm, ovate, gold-brown, translucent, slightly iridescent, the cells mostly isodiametric, the apices acute or filiform, the filiform portion up to 0.5 mm long when present, the margins erose to entire, sometimes with a few broad teeth or cilia up to 0.2 mm long, adaxially moderately pubescent, the hairs erect to spreading, otherwise similar to those of the abaxial rachises; lamina tissue between the veins abaxially and adaxially glabrous; veins visible on both sides of the lamina, the veins glabrous adaxially, abaxially the larger veins sparsely pubescent, the hairs 0.5 mm long, 4-celled, smaller veins moderately provided with 0.2-0.7 mm long, non-glandular, erect, reddish, filiform, scales, these uniseriate or rarely bifurcating; lamina margins sparsely ciliate, the hairs restricted to proximal portions of the pinnules, the hairs 0.3 mm long, 3-celled; indusia present, 0.4-0.8 mm wide, brown, often folded or lost in mature sori, the margins sparsely ciliate, the cilia 0.1 mm long, brown.
Distribution: Endemic to the Isla Masafuera (Alexander Selkirk Island) in the Juan Fernández Islands in the South Pacific Ocean, known only from the Valley of Quebrada de las Vacas.
Comments: Megalastrum masafuerae is distinguished by large indusia (0.4-0.8 mm wide) with sparsely ciliate margins, axes and veins sparsely pubescent abaxially, and nearly glabrous lamina margins with marginal hairs (if any) restricted to the proximal portions of the sinuses. Megalastrum glabrius, also endemic to Isla Masafuera, is indusiate, but its indusia are smaller (0.3-0.4 mm wide). Furthermore, it lacks hairs on the laminae and has puberulent adaxial axes. Megalastrum inaequalifolium on Isla Masatierra also has indusia, but it differs by the indusia being fugacious, smaller (ca. 0.2 mm wide), and bearing (1)5-10 erect acicular hairs, as well as by its pilose axes and evenly ciliate lamina margins that are provided with 0.5-0.7 mm long hairs.
Etymology: The specific epithet is derived from the original name given to Alexander Selkirk Island, Isla Masafuera.