Dryopteris bernieri Tardieu

2. Dryopteris bernieri Tardieu View in CoL

( Figs 8 View FIG ; 9 View FIG )

Notulae Systematicae (Paris) 15 (2): 161 (Apr. 1956).

— Type: Bourbon ( Réunion), Lépervanche-Mézière 22 (holo-, P 00349606 !) .

OTHER MATERIAL EXAMINED. — Comoro Islands (Anjouan). Johanna Island , III.1977, Bewsher s.n. ( K).

Réunion. Bourbon , 1847, Armange s.n. ( P 00349616). — Bourbon, 1835, Bernier 96 ( P 00349608). — Route forestière du pic Maïdo, falaise ombragée d’une ravine, 1750 m, 2.XI.1973, Badré 773 ( P 00349619). — Palmiste rouge, vallée du Bras des Calumets, plantation d’ Eucalyptus, 1000 m , 15.XI.1973, Badré 902 ( P 00349617, P 00349618). — Sentier de Cilaos vers l’îlet à Cordes, entre Cilaos et le bras Rouge, 17.XI.1973, Badré 974 ( P 00349620, P 00349621). — Île Bourbon, 15.II.1847, Boivin s.n. ( P 00349609). — plaine des Cafres au pied du Piton de Villers, 7.VI.1851, Boivin s.n. ( P 00349612). — Oraire, VII.1851, Boivin s.n. ( P 00349611). — Île Bourbon, Boivin s.n. ( P 00349614). — Cilaos, prés de la chapelle, 600 m, 12.I.1963, Cadet 322 ( P 00349629). — Fissure profonde sommet du Rempart de Belle courbe, 2300 m, 12.IX.1968, Cadet 1542 ( P 00349628). — Haute vallée de la rivière des Remparts, sous-bois sur falaise, 1600 m, 20.XI.1968, Cadet 1713 ( P 00349626, P 00349627). — La Réunion, sous-bois d’ Acacia et d’ Hypericum , bras Sec, cirque de Cilaos, 1300 m, 7.II.1969, Cadet 1904 ( P 00349624). — La Réunion, terrestre, sous-bois de végetation arbustive, cirque de Cilaos, 1200 m, 16.II.1973, Cadet 4115 ( P 00349622). — La Réunion, terrestre, sousbois de forêt sèche, cirque de Grand Bassin, vers 1000 m, 28.VI.1973, Cadet 4375 ( P 00349623). — La Réunion, sous-bois de végétation arbustive pionnière, vallée du Bras Rouge, cirque de Cilaos au-dessous de l’Îlet du Salazes, 1300 m, 22.III.1974, Cadet 4559 ( P 00349625). — Île Bourbon, De Cordemoy s.n. ( BM 000801043). — Île Bourbon, VII.1837, Gaudichaud s.n. ( P 00349615- A only). — Réunion, Cilaos Distr., road from Cilaos to Îlet à Cordes on steep earthbank, in deep shade, occasional, 1000 m, 20.IX.1984, Jacobsen 5541 ( FR). — Bourbon, Johnstone 80 ( BM 000801026). — Bourbon, Lépervanche-Mézière 22 ( P 00349606). — La Réunion, 1891, Maigre s.n. ( P 00349607). — Réunion, Potier s.n. ( P 00349610).

Sine Loco. Lépervanche-Mézière s.n. ( P 00349613).

DESCRIPTION

Plants terrestrial. Rhizome short-decumbent, up to 70 mm long and 16 mm in diameter, set with roots, closely spaced stipe bases and scales, the scales ferrugineous, chartaceous, adnate, linear-acuminate, up to 35 × 4.5 mm, regularly set with capitate glands along the margins and laminae, the apex terminates in a short series of oblong cells. Fronds crowded, arching, up to 1.2 m long; stipe up to 510 mm long and 7 mm in diameter, proximally castaneous, stramineous higher up, adaxially shallowly sulcate, proximally densely set with scales similar to those on the rhizome, up to 45 × 4 mm, moderately to closely set with capitate glands, sparsely scaled higher up, the scales ferrugineous to stramineous, sessile, ovatecaudate to narrowly lanceolate-caudate, up to 9 × 3 mm, cordate, the margins and laminae regularly set with capitate glands, often also with a few scattered pluricellular, mostly uniseriate hairs, which often is glandular, the scale apex terminates in a short series of oblong cells; lamina deltate to broadly ovate, up to 610 × 340 mm, to 2-pinnate-pinnatifid, pinnatifid towards the apex, with up to 8 petiolated pinna pairs; rachis ferrugineous, sulcate adaxially, narrowly winged towards the apex, closely glandular, sparsely scaled, the scales sessile, narrowly lanceolate-caudate to subulate-caudate, up to 4 × 0.6 mm, cuneate, the margins and laminae regularly set with capitate glands, the apex terminates in a short series of oblong cells; pinnae opposite to alternate, mostly overlapping, petiolate at base, adnate and basiscopically decurrent with rachis winged towards lamina apex, petiole up to 13 mm long, basal pair longest and conspicuously basiscopically developed, up to 1-pinnate-pinnatifid, inaequilaterally ovate, up to 290 × 150 mm, pinnae higher up more symmetric, oblong-acuminate to linear-acuminate, with up to 6 petiolated pinnule pairs; pinna-rachis sulcate adaxially, narrowly winged towards the apex, closely glandular, sparsely scaled abaxially, the scales similar, but smaller than those on the rachis; pinnules petiolate, the petiole up to 2.5 mm long, opposite to alternate, pinnatifid, not or slightly overlapping, firmly herbaceous, dark green adaxially, paler abaxially, pinnatifid, acroscopic pinnule on basal pinnae linear-acuminate to ovate, up to 70 × 24 mm, basiscopic pinnule on basal pinnae linear-acuminate to narrowly ovate,up to 90 × 32 mm, abaxially with isocytic hairs mostly along the veins, the hairs often with one or more glandular cells near the base; pinnule-rachis adaxially convex, narrowly winged, closely glandular adaxially and abaxially, the glands capitate, (60-)106(-140) µm long, and with scattered scales, the scales ferrugineous, chartaceous, narrowly lanceolate-caudate to subulate-caudate, glandular along the margins and laminae; segments proximally sessile, adnate higher up, oblong-obtuse to ovate obtuse, up to 20 × 8 mm, larger segments often shallowly lobed, denticulate, adaxially and abaxially closely set with capitate glands along and between the veins.Venation obscure adaxially,evident abaxially, lateral veins in segments simple or once forked, ending in the teeth near the margin.Stomata mostly of the polocytic type, (32-)47(-56) µm long. Sori essentially 2-seriate on pinnules, inframedial on predominantly anadromous vein branches, up to 1.5 mm in diameter and discrete at maturity; indusium castaneous, firmly herbaceous, up to 1.7 mm in diameter, reniform, often strongly recurved, entire to shallowly repand, eglandular or glandular along the margin, often also on the lamina. Sporangium stalk simple, with several hairs and/or glands, capsule with (12-)14(-17) indurated annulus cells, epistomium (3-)4(-7)-celled, hypostomium (4-)6-celled. Spores brown, (36-)42(-52) × (24-)29(-36) µm long.

DIAGNOSTIC FEATURES AND RELATIONSHIPS

Dryopteris bernieri can be separated from other Dryopteris species from Réunion by the axes being closely set with capitate glands, a feature that is absent from other Dryopteris species on the island. Similar glands also occur adaxially and abaxially along and between the veins on the lamina. The scales of D. bernieri are also regularly set with capitate glands along the margins and laminae.

Fraser-Jenkins (1986) does not list the species, but it is here placed in section Marginatae Fraser-Jenk. The occurrence and distribution of capitate glands on the lamina and the similar scale morphology suggest it being related to D. glandulosopaleata J.P.Roux from Africa. Dryopteris bernieri is separated from D. glandulosopaleata in them being geographically isolated, and in the stomata and spores of D. bernieri being significantly smaller than that of D. glandulosopaleata .

DISTRIBUTION AND HABITAT

Dryopteris bernieri has a somewhat disjunct distribution occurring on Réunion, where it grows at elevations ranging between 600 and 2300 m on both Massif du Piton des Neiges and Massif de la Fournaise and on Anjouan (Johanna Island/ Anjouan), Comoros ( Fig. 10 View FIG ). Both massifs are the result of successive volcanic eruptions, but their subsequent erosion has resulted in the formation of radiating valleys with steep flanks. The species grows in deep shade in wet evergreen forests, on earth banks and screes along the steep sloped valleys, and in Eucalyptus plantations.Tardieu-Blot (1956a, 1958) noted that the species is also present in the “ Comores ” by citing a Boivin collection. I have not seen any collections of D. bernieri from that island group.