Dryopteris subcrenulata C. Chr.
Creators: name: Roux, Jacobus P.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Polypodiopsida
Polypodiales
Dryopteridaceae
Dryopteris
Dryopteris subcrenulata

description: 7. Dryopteris subcrenulata (Baker) C.Chr.
(Figs 22; 23)
Index filicum: 295 (18 Nov. 1905). — Nephrodium subcrenulatum Baker, Journal of the Linnean Society, Botany 16: 202 (1877). — Aspidium subcrenulatum (Baker) Kuhn, Von der Decken’s Reisen in Ost-Afrika in 1851-1861 3 (3): 65 (Aug.-Sep. 1879).
— Type: Madagascar, Antananarivo, H. Gilpin s.n. (holo-, K 000351090!, K 000351091!).
Dryopteris mangindranensis Tardieu, Notulae Systematicae (Paris) 15 (2): 161, 162 (Apr. 1956). — Type: Madagascar, montagnes au Nord de Mangindrano, jusqu’aux sommets d’Ambohimirahavavy, 1900-2500 m, Humbert 25054 (holo-, P00483232!; iso-, K000351050!,).
OTHER MATERIAL EXAMINED. — Madagascar. Ambohimitombo forest, 27.XI.1894, Forsyth Major 193 (K). — Montagnes au Nord du Mangindrano (haute Maevarano), jusqu’au sommet d’Ambohimirahavavy (partage des eaux Mahavavy-Androranga: Centre-Nord): haute Bemafo (affluent de l’Androranga), forêt ombrophile sur latérite de gneiss, 1900 m, Humbert & Capuron 25054 (P 00349516). — Montagnes au Nord de Mangindrano (haute Maevarano) jusqu’aux sommets d’Ambohimirahavavy (partage des eaux Mahavavy-Androranga: Centre-Nord), 1800- 2000 m, 19.I-12. II.1951, Humbert & Capuron 25055 (P 00349518). — Massif de Marivorahona au sud-ouest de Manambato (haute Mahavavy du nord, district d’Ambilobe), forêt ombrophile sur gneiss, 1750- 2000 m, 18- 26.III.1951, Humbert & Capuron 25810 (P 00349519). — Tampoketsa au N d’Ankazobe (Centre), forêt d’Ambohitantely et reste de forêts aux alentours, vers 1600 m, 1933, Humbert 11127 (P 00349502). — Massif du Kalambatitra (Centre-Sud), Mont Beanjavidy: forêt ombrophile, 1500- 1730 m, XI.1933, Humbert 12064 (P 00349520). — Mt Tsaratanana, 2000 m, Humbert 16165 (P 00349510). — Bassin supérieur du Sambirano, forêt ombrophile sur sol siliceux, 1700 m, XI-XII.1937, Humbert 18656 (P 00349511). — Mt Tsaratanana, 2000 m, IV.1923, Perrier de la Bathie 16458 (P 00349517). — Massif de Manongarivo, bois vers 800 m, III.1909, Perrier de la Bathie 7445 (P 00349501). — Antananarivo, 4/76, Pool s.n. (K). — Antsiranana, Andapa, RNI 12 du Marojejy, au bord d’un affluent de la rivière Manantenina, à 10 km au Nord-Ouest du village de Manantenina, 820 m, 20.X.1996, Rakotondrainibe 3429 (P 00084909, P 00084910). — Toamasina, near Andisabe, forest of Mantadia, beyond the graphite mine, 900 m, 3.XI.1994, Van der Werff, McPherson & Rapanarivo 13626 (PRE).
DESCRIPTION
Plants terrestrial. Rhizome short-decumbent to suberect, up to 110 mm long and 15 mm in diameter, set with roots, closely spaced stipe bases and scales, the scales ferrugineous, thinly chartaceous, broadly attached, lanceolate to subulate, up to 15 × 3.5 mm, proximally entire, denticulate towards the apex, often with scattered glands and/ or one or more pluricellular, mostly recurved outgrowths along the margin, the smaller scales often with more marginal outgrowths, the apex filiform, terminating in a uniseriate series of oblong cells. Fronds caespitose, suberect to arching, up to 7 per plant, up to 1.2 m long; stipe up to 640 mm long and 8 mm in diameter, proximally castaneous, stramineous higher up, sulcate adaxially, initially densely scaled, the scales fugaceous, castaneous, chartaceous, the larger scales broadly attached, ovate to lanceolate, up to 15 × 3.4 mm, cordate to broadly cuneate, denticulate, often irregularly glandular along the margins, and/or with one or more mostly recurved pluricellular outgrowths, the apex filiform, terminating in a series of oblong cells, the smaller scales short-stalked, the stalk often glandular, subulate, narrowly cuneate, denticulate, the apex terminating in a short series of oblong cells; lamina ovate to broadly ovate, 1-pinnatepinnatifid to 2-pinnate, up to 710 × 420 mm, with up to 16 petiolated pinna pairs, the basal pinnae widely spaced, becoming increasingly more closely spaced distally, never overlapping; rachis stramineous, sulcate adaxially, narrowly winged towards the apex, sparsely scaled, the scales stramineous to ferrugineous, chartaceous, short-stalked, linear to subulate, up to 11 × 2 mm, entire, irregularly denticulate, often with scattered glands along the margins and with numerous filiform outgrowths, the apex terminates in a short series of oblong cells; pinnae petiolate, the petiole up to 4 mm long, near opposite to alternate, becoming increasingly basiscopically decurrent along the rachis and more broadly attached towards the lamina apex, falcate, herbaceous, one to two basal pinna pairs inaequilaterally oblong-acuminate to narrowly lanceolate, pinnatifid to 1-pinnate, symmetrically oblong-acuminate towards the lamina apex, becoming less deeply lobed towards lamina and pinna apices, basal pinnae longest or not, up to 260 × 62 mm, with up to 8 petiolated pinnule pairs; pinna-rachis shallowly sulcate adaxially, glabrous, pronounced abaxially, narrowly winged for most of the length, sparsely scaled, the smaller scales stramineous to ferrugineous, chartaceous, shortstalked, the stalk often glandular, filiform, up to 5 × 1.4 mm, denticulate or with several filiform marginal outgrowths, the apex terminates in a short series of oblong cells, the larger scales sessile, cordate to cordate-imbricate; pinnules sessile or petiole up to 1 mm long, acroscopic pinnule on basal pinnae oblong-obtuse to oblong acute, up to 28 × 13 mm, basiscopic pinnule on basal pinnae up to 24 × 10 mm, shallowly to deeply lobed, the lobes entire to shallowly crenulated to obtusely denticulate, oblong-obtuse, mostly widening acroscopically and basiscopically towards the lamina apex, up to 8 × 5 mm, glabrous adaxially, or with a few isocytic hairs near the costa, abaxially with isocytic hairs up to 0.8 mm long along and near the veins, hairs often glandular near the base. Venation evident, lateral veins in pinnules pinnately branched, forked or simple, vein branches end near the margin. Stomata mostly of the polocytic type, (34-)50(-58) mm long. Sori 2-seriate on lobes, medial to supramedial on predominantly anadromous vein branches, up to 1.4 mm in diameter; sporangium stalk simple or haired, capsule with 14(-15) indurated annulus cells, epistomium 4(- 5)-celled, hypostomium 4(-5)-celled. Indusium castaneous, firmly chartaceous, reniform, entire, up to 1.5 mm in diameter, margins strongly recurved, entire. Spores 64 per sporangium, brown, with short reticulate ridges and bulges, (32-)38(-42) × (22-)23(-24) mm.
DIAGNOSTIC FEATURES AND RELATIONSHIPS
Characteristic of the species is the narrow rhizome and frond scales, which are denticulate and which often bear a few very long filiform outgrowths along the margins. The outgrowths are mostly uniseriate and are composed of several long cells. The joints between these cells are sinuate.
DISTRIBUTION AND HABITAT
A species confined to Madagascar, where it occurs in moist evergreen forests, at elevations ranging between 800 and 2000 m (Fig. 24).
description: Published as part of Roux, Jacobus P., 2011, The fern genera Dryopteris and Nothoperanema (Dryopteridaceae) in Madagascar and neighbouring Indian Ocean islands, including Saint Paul, pp. 7-67 in Adansonia (3) (3) 33 (1) on pages 46-50, DOI: 10.5252/a2011n1a1, http://zenodo.org/record/5197315