Taxon Details: Megalastrum angustum R.C.Moran, J.Prado & Labiak
Taxon Profile:
Narratives:
Family:
Dryopteridaceae (Pteridophyta)
Dryopteridaceae (Pteridophyta)
Scientific Name:
Megalastrum angustum R.C.Moran, J.Prado & Labiak
Megalastrum angustum R.C.Moran, J.Prado & Labiak
Accepted Name:
This name is currently accepted.
This name is currently accepted.
Description:
by: R.C. Moran, J. Prado, and P.H. Labiak
Type: Haiti. Massif de la Selle, Port au Prince, Morne Malanga, shady gully, 1200 m, 27 Jan 1926, E. L. Ekman 5442 (holotype: NY; isotypes: K, S, US)
Description: Leaves up to 1.2 m long; scales of the petiole bases 2-5 × 0.3-0.5 cm, linear-lanceolate, entire, brown; laminae 0.7-0.8 m long, 2-pinnate-pinnatifid at base and medially; basal pinnae ca. 3.0-4.5 cm long, equilateral; pinnules short-stalked to sessile, 1.0-1.5 cm long; pinna rachises abaxially non-glandular, scaly and without hairs, the scales 3-3.5 mm long, linear-lanceolate, brown, entire, non-bullate, rachises adaxially non-glandular, densely pubescent, the hairs 0.4-1.0 mm long, 4-7-celled, the scales like those on the abaxial surfaces; costules on the abaxial surface eglandular, sparsely pubescent and scaly, the hairs 0.3-2.5 mm long, 2- or 4-celled, acicular, erect to spreading, the scales like those on the pinna rachises abaxially, the adaxial surface densely pubescent, the hairs 0.5-0.7 mm long, 3-5-celled, substrigose; laminar tissue between veins glabrous on both surfaces (uniseriate reddish appressed scales may be present); veins visible on both surfaces, abaxially non-glandular, sparsely pubescent and non-scaly, the hairs 0.3-0.5 mm long, 3- or 4-celled, the scales ca. 0.2-0.3 mm long, uniseriate, appressed, reddish, adaxially non-glandular, sparsely pubescent, the hairs 0.2-0.5 mm long, 3- or 4-celled; laminar margins ciliate, the hairs ca. 0.3-0.5 mm long, 3-5-celled, ascending to spreading, glandular hairs absent; indusia absent.
Distribution and ecology: Haiti, known only from the type.
Comments: Megalastrum angustum has the smallest basal pinnae in the genus, only 3.0-4.5 cm long (Fig. 1B). The specific epithet angustum refers to the narrow laminae, which are widest at the middle and narrowed toward the base. Few species of Megalastrum have similarly narrowed laminae. One Antillean species with narrowed laminae, M. aripense, can be separated by the characters given in the key. Besides narrowed laminae, the pinnules are small (only 1.0-1.5 cm long) and vary from crenate to pinnatifid, not pinnatisect or more divided as in most other species of Megalastrum.
by: R.C. Moran, J. Prado, and P.H. Labiak
Type: Haiti. Massif de la Selle, Port au Prince, Morne Malanga, shady gully, 1200 m, 27 Jan 1926, E. L. Ekman 5442 (holotype: NY; isotypes: K, S, US)
Description: Leaves up to 1.2 m long; scales of the petiole bases 2-5 × 0.3-0.5 cm, linear-lanceolate, entire, brown; laminae 0.7-0.8 m long, 2-pinnate-pinnatifid at base and medially; basal pinnae ca. 3.0-4.5 cm long, equilateral; pinnules short-stalked to sessile, 1.0-1.5 cm long; pinna rachises abaxially non-glandular, scaly and without hairs, the scales 3-3.5 mm long, linear-lanceolate, brown, entire, non-bullate, rachises adaxially non-glandular, densely pubescent, the hairs 0.4-1.0 mm long, 4-7-celled, the scales like those on the abaxial surfaces; costules on the abaxial surface eglandular, sparsely pubescent and scaly, the hairs 0.3-2.5 mm long, 2- or 4-celled, acicular, erect to spreading, the scales like those on the pinna rachises abaxially, the adaxial surface densely pubescent, the hairs 0.5-0.7 mm long, 3-5-celled, substrigose; laminar tissue between veins glabrous on both surfaces (uniseriate reddish appressed scales may be present); veins visible on both surfaces, abaxially non-glandular, sparsely pubescent and non-scaly, the hairs 0.3-0.5 mm long, 3- or 4-celled, the scales ca. 0.2-0.3 mm long, uniseriate, appressed, reddish, adaxially non-glandular, sparsely pubescent, the hairs 0.2-0.5 mm long, 3- or 4-celled; laminar margins ciliate, the hairs ca. 0.3-0.5 mm long, 3-5-celled, ascending to spreading, glandular hairs absent; indusia absent.
Distribution and ecology: Haiti, known only from the type.
Comments: Megalastrum angustum has the smallest basal pinnae in the genus, only 3.0-4.5 cm long (Fig. 1B). The specific epithet angustum refers to the narrow laminae, which are widest at the middle and narrowed toward the base. Few species of Megalastrum have similarly narrowed laminae. One Antillean species with narrowed laminae, M. aripense, can be separated by the characters given in the key. Besides narrowed laminae, the pinnules are small (only 1.0-1.5 cm long) and vary from crenate to pinnatifid, not pinnatisect or more divided as in most other species of Megalastrum.