Dryopteris

Roux, Jacobus P., 2011, The fern genera Dryopteris and Nothoperanema (Dryopteridaceae) in Madagascar and neighbouring Indian Ocean islands, including Saint Paul, Adansonia (3) 33 (1), pp. 7-67 : 60

Dryopteris hybrid

“La Réunion” ( D. pentheri × D. aquilinoides ), Roux, Flore de Mascareignes, Ptéridophytes: 272, 273 (2008). MATERIAL EXAMINED. — Réunion. Plateau des Fleurs Jaunes au-dessous du col de Taibit, cirque de Cilaos, 1700 m, 22.III.1974, Cadet 4558 (P00349602, P00349603).

DESCRIPTION

Plants terrestrial. Rhizome unknown, but probably short-decumbent. Fronds caespitose, erect, up to 1.4 m long; stipe brown to stramineous, up to 550 mm long and 10 mm in diameter, cicatricate, proximally densely scaled, the scales higher up fugacious, ferrugineous, narrowly lanceolate to oblongacuminate, up to 55 × 7 mm, with filiform marginal outgrowths; lamina firmly herbaceous, ovate, up to 840 × 460 mm, 3-pinnate-pinnatifid, with up to 17 petiolated pinna pairs; rachis stramineous, initially moderately scaled, the scales stramineous, narrowly lanceolate to oblong-acuminate, with filiform marginal outgrowths, up to 16 × 3 mm; pinnae petiolate, the petiole up to 13 mm long, basal pinnae basiscopically developed, inaequilaterally narrowly ovate, up to 350 × 140 mm, oblong-acuminate towards the apex, to 2-pinnate-pinnatifid, basal pinna pair longest, opposite to alternate, with up to 11 petiolated pinnule pairs; pinna-rachis narrowly winged distally, sparsely to moderately scaled, the scales stramineous, narrowly lanceolate-caudate to oblong-caudate, up to 7 × 3 mm, with filiform outgrowths along the margin; pinnules petiolate, the petiole up to 2 mm long, the basal pinnules somewhat basiscopically developed, lanceolate to oblong-acuminate, up to 180 × 30 mm, to 1-pinnate-pinnatifid; costa moderately scaled abaxially, the scales stramineous, narrowly lanceolate to filiform, up to 3 × 1 m, with filiform marginal outgrowths; segments petiolate, the petiole up to 1 mm long, sessile to adnate and basiscopically decurrent towards the pinnule apex, lanceolate, ovate, or oblong-obtuse, up to 18 × 9 mm, obtusely lobed, denticulate, abaxially sparsely set with stramineous to ferrugineous filiform scales and hairs, also with unicellular oblong hairs up to 134 µm long along the costules and veins, glabrous adaxially. Sori circular, medial on predominantly anadromous vein branches, discrete or touching at maturity, essentially uniseriate; sporangium stalk haired; indusium persistent, brown, firmly herbaceous, reniform, repand, up to 8 mm in diameter. Spores black, aborted.

DISTRIBUTION AND HABITAT

In pioneer vegetation among rocks at about 1700 m.