Dryopteris bojeri (Baker) Kuntze

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 : 31-34

3. Dryopteris bojeri (Baker) Kuntze

( Figs 11 ; 12 )

Revisio generum plantarum 2: 812 (5 Nov. 1891). — Nephrodium bojeri Baker , Synopsis filicum 7: 280 (4 Oct. 1867).

—Type: Mauritius, Bojer s.n. (lecto-, K!, designated by Roux [2009: 121]; isolecto-, M 0065885 !).

Nephrodium amplum Bory, Voyage aux Indes Orientales. Botanique 2 (1): 62, 63 (24 May 1833).

— Type: “à l’Île Maurice ”, Bélanger s.n. (holo-, P 00349575 !).

Nephrodium filix-mas auct. non (L.) Rich., Flora of Mauritius and the Seychelles: 496 (1877), pro parte.

OTHER MATERIAL EXAMINED. — Mauritius. Barkly & Lady Barkly s.n. ( BM 000801021, BM 000801022). — On rocky side of Piton at Ripailles, Barkly & Lady Barkly s.n. ( BM 000801027). — Île Maurice, IX-X.1849, Boivin s.n. ( P 00349594, P 00349595). — Île de France, Commerson s.n. ( P 00349589). — Mauritius, Corps de Gardes, Pike s.n. ( NY). — Bois de Moka à l’Île de France, sine coll. s.n. ( P 00349590, 2 sheets).

Sine Loco. Barkly & Lady Barkly s.n. ( BM 000801028) ; Boivin s.n. ( P 00349591, P 00349592, P 00349593) ; Boivin s.n. ( BM 000801046) ; Bojer s.n. ( K) ; Bojer s.n. ( M 0065885) ; Duncan s.n. ( BM 000801025) ; Mc Gregor s.n. ( BM 000801023, BM 000801029) ; sine coll. s.n. ( P 00349571) ; sine coll. s.n. ( P 00349587) ; sine coll. s.n. ( BM 000801024).

DESCRIPTION

Plants terrestrial. Rhizome unknown. Fronds up to 1.2 m long; stipe stramineous, sulcate adaxially, up to c. 490 mm long and 6 mm in diameter, initially sparsely to moderately scaled, proximally densely scaled, subglabrous later, the scales ferrugineous, chartaceous, linear-attenuate, up to 32 × 5 mm, adnate, variously set with glands and long uniseriate pluricellular filiform outgrowths along the margin, the apex filiform; lamina anadromous, catadromous towards apex, broadly ovate to deltoid, up to 580 × 620 mm, to 3-pinnate, with up to 13 petiolated pinna pairs, distal pinnae become sessile and eventually adnate and increasingly basiscopically decurrent; rachis stramineous, adaxially sulcate, narrowly winged near the apex, sparsely scaled, the scales stramineous, thinly chartaceous, sessile, narrowly lanceolate to subulate, up to 4 × 1 mm, narrowly to broadly cuneate, often irregularly set with glands and long uniseriate pluricellular outgrowths, the apex terminates in a series of oblong cells; pinnae petiolate, the petiole up to 4 mm long, spaced or overlapping, near opposite to alternate, the basal pinna pair longest, to 2-pinnate, basal pinnae basiscopically developed, inaequilaterally lanceolate, up to 370 × 135 mm, pinnae towards the apex inaequilaterally oblong, with up to 10 petiolated pinnule pairs; pinna-rachis stramineous, adaxially sulcate, narrowly winged towards the apex, rarely sparsely glandular at the base, glands capitate, up to 62 µm long, sparsely scaled, the scales similar to those on the rachis; pinnules petiolate, the petiole up to 2 mm long, proximally spaced, slightly overlapping towards the pinna apex, the proximal basiscopic pinnule longest or not, acroscopic pinnule on basal pinnae ovate-acuminate to oblong-acuminate, up to 57 × 26 mm, pinnatifid, basiscopic pinnule on basal pinnae inaequilaterally lanceolate to oblong-acuminate, up to 105 × 34 mm, to 1-pinnate; pinnule-rachis stramineous, adaxially sulcate, pronounced abaxially, sparsely set with scales and hairs, the scales similar, but smaller than those on the pinna-rachis, the hairs isocytic; segments herbaceous, petiolate, the petiole up to 1 mm long, narrowly ovate to oblong-obtuse, up to 18 × 9 mm, glabrous adaxially, abaxially sparsely set with isocytic hairs along the costule and veins, hairs often long and long-celled, often glandular near the base, larger segments shallowly lobed, the lobes denticulate. Venation evident, lateral veins in pinnule lobes pinnately branched, vein branches end in the teeth near the margin. Stomata mostly of the polocytic type, (34-)45(-54) µm long. Sori essentially 2-seriate on larger pinnule lobes, discrete, supramedial on predominantly anadromous vein branches, up to 1 mm in diameter at maturity; indusium dark brown, firmly herbaceous, reniform, entire or shallowly repand, strongly recurved.Sporangium stalk simple, glandular, or haired, capsule with (14-)15(-16) indurated annulus cells, epistomium 4-celled, hypostomium 4-celled. Spores brown, 64 per sporangium, perispore folded to form pronounced reticulate ridges, exospore (32-)34(-44) × (18-)20(-22) µm.

DIAGNOSTIC FEATURES AND RELATIONSHIPS Diagnostic of the species are the scales, which bear numerous exceptionally long filiform outgrowths along their margins.

DISTRIBUTION AND HABITAT

Dryopteris bojeri is endemic to Mauritius and appear not to have been collected there recently ( Fig. 13 ). Lorence (1978) does not list the species, but he may have identified it as D. aquilinoides . Nothing is known about the ecology of the species.

Figures

FIG. 11. — Isosyntype of Dryopteris bojeri (Baker) Kuntze, Bojer s.n. (M0065885).

FIG. 12. — Indumentum and indusium of Dryopteris bojeri (Baker) Kuntze: A, stipe scale; B, rachis scale; C, D, pinna-rachis scale; E, F, scales from abaxial lamina surface; G, H, hairs from abaxial lamina surface; I, indusium. Commerson s.n. (P00349589). Scale bars: A-F, I, 1 mm; G, H, 0.2 mm.

FIG. 13. — Distribution of Dryopteris bojeri (Baker) Kuntze in Mauritius.