Dryopteris wardii (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 : 55-60

Dryopteris wardii (Baker) Kuntze

( Fig. 28 )

Revisio generum plantarum 2: 814 (5 Nov. 1891). — Nephrodium wardii Baker , Synopsis filicum , ed. 2: 500 (Oct. 1874). — Polystichopsis wardii (Baker) Tardieu, Notulae Systematicae (Paris) 15 (2): 176 (Apr. 1956). — Araiostegia wardii (Baker) Tardieu , Adansonia 5 (4): 493 (1965). — Type: Seychelles, Ward s.n. (lecto-, BM000801014!, here designated); Seychelles, Neville s.n. (syn-, BM000801015!, K000228190!); Horne 177 (syn-, K000228193!).

OTHER MATERIAL EXAMINED. — Seychelles. Mahé, 1853, Rawson 196 (BM000801017). — Mahé, 1800 ft., Ward s.n. (BM000801014). — Seychelles, Barkly s.n. (BM000801015). — Seychelles (excl. Horne s.n.), sine coll. s.n. (BM000801016). — Silhouette, 2.VIII.1908, Gardiner s.n. (BM000801018).

DESCRIPTION

Plants terrestrial. Rhizome “horizontal, c. 20 mm thick” ( Christensen 1912: 413). Fronds anadromous, up to c. 820 mm long; stipe castaneous, adaxially sulcate along the entire length, up to 320 mm long and 6 mm in diameter, proximally densely scaled, sparsely scaled to glabrous higher up, the scales ferrugineous, chartaceous, broadly attached, narrowly lanceolate to subulate, up to 14 × 2 mm, entire to denticulate, irregularly glandular along the margins, the apex terminates in a short series of oblong cells; lamina anadromous, broadly ovate, up to 500 mm long (clearly longer, but material incomplete) and 900 mm wide, to 4-pinnate, with up to 9 (perhaps more) petiolated pinna pairs; rachis castaneous, adaxially shallowly sulcate, narrowly winged towards the apex, initially sparsely set with filiform scales and few-celled hairs bearing one or more glandular cells near the base, glabrous later; pinnae petiolate, the petiole up to 18 mm long, alternate, proximally widely spaced, somewhat overlapping, the basal pair longest, up to 3-pinnate, up to 440 × 215 mm, inconspicu- ously basiscopically developed or not, proximally inaequilaterally triangular, symmetrically lanceolate higher up, with up to 11 petiolated pinnule pairs; pinna-rachis castaneous, adaxially shallowly sulcate, narrowly winged towards the apex, initially sparsely set with hairs and glands similar to those on the rachis, glabrous later; pinnules petiolate, the petiole up to 6 mm long, distal pinnules becoming increasingly more broadly attached and basiscopically decurrent, proximally widely spaced, more closely spaced distally, mostly slightly overlapping, up to 2-pinnate, acroscopic pinnule on basal pinnae up to 132 × 58 mm, basiscopic pinnule on basal pinnae ovate, lanceolate, or oblong-acuminate, up to 115 × 48 mm; pinnule-rachis shallowly sulcate adaxially, the sulcus confluent with that of the pinna-rachis, initially sparsely set with glands and hairs similar to those on the pinna-rachis, glabrous later; segments petiolate, the petiole up to 2 mm long, distal segments becoming increasingly more broadly attached and basiscopically decurrent along the costa, firmly herbaceous, mostly somewhat overlapping, up to 1-pinnate, acroscopic segment on basal pinnule up to 33 × 16 mm, basiscopic segment on basal pinnule up to 29 × 18 mm, ovate to narrowly lanceolate, oblong and falcate towards the apex; costa narrowly winged for most of the length, sparsely set with glands and hairs bearing one or more glandular cells near the base; ultimate segments sessile, becoming increasingly more broadly attached towards the segment apex, the basal ultimate segments inaequilaterally elliptic to oblong, up to 11 × 6 mm, trapeziform to falcate higher up, obtusely dentate, glabrous adaxially, abaxially sparsely set with glands (56-)68(-90) mm long and hairs bearing one or more glandular cells near the base.Venation anadromous, evident, pinnately branched in ultimate segments, ending in teeth near the margin. Stomata mostly of the polocytic type, (38-)48(-58) mm long. Sori 2-seriate on larger ultimate segments, medial on anadromous vein branches; indusium castaneous, chartaceous, up to 1.2 mm in diameter, reniform, entire or with scattered glands, glandular and haired adaxially, the hairs often bearing a gland near the base. Sporangium stalk simple or haired, apical cell of hair pyriform and gland-like, capsule with (13-)14(-17) indurated annulus cells, epistomium (3-)4(-5)-celled, hypostomium (3-)4(-5)-celled. Spores 64 per sporangium, brown, with narrow to broad reticulate ridges, exospore (22-)47(-52) × (24-)26(-30) mm.

REMARKS

Baker (1874: 500) cited three collections, Ward s.n., Neville s.n. and Horne 177, when he described Nephrodium wardii . Tardieu-Blot (1960: 180) cites the Ward s.n. and Neville s.n. collections from the BM and the Horne 177 collection from K. The Ward s.n. collection (BM000801014) was made at Mahé, Seychelles. The sheet contains three immature fronds and a label in the hand of Baker reading “ Lastrea 27-from Mahé-Seychelles-elev 1800 ft Swinburn Ward Esq Febr/69”, “ Lastrea ” and the date appear to have been added later as it is in a darker ink. This sheet conforms to the protologue and it may serve as one of the syntypes .

Two further sheets at BM under this name have labels in the hand of Baker.The first, BM000801015, formed part of the Sir H. & Lady Barkly Herbarium. The label reads “ Lastrea Seychelles W. Nevill. I be-

lieve this to be new. It is certainly nothing in the

Synopsis and would come in near N. amplum page 285(.) Baker 29/1/68(.) We have not received any Seychelles ferns from W. Nevill. ” This specimen is viewed as one of the syntypes .

The second sheet, BM000801016, also formed part of the Sir H. & Lady Barkly Herbarium. This sheet contains two different elements, the frond on the left has a typed label reading “Seychelles- John Horne”. A further label on brown paper in the hand of Baker gives “ Lastrea Wardii Baker MSS ”. This material belongs to a Lastreopsis species. At the right bottom corner of this sheet are two labels, the upper one on white paper and the lower one on brown paper. The upper label reads “ Lastrea 27 Seychelles (.) I cannot make this out from the specimen sent. It is certainly a Lastrea (.) Baker 29/1/68”. The label on brown paper reads “7-Reduit(.) Acrophorus sp : unnamed Baker-Mahé, Seychelles (.) This is appearing to be the Microlepia ? 27 Seychelles which Captain Beddome states to be a Lastrea . Letter of 15/3/67(.) May this not be the same as W Nevill’s Lastrea- A-while M Baker says is new and nearest N. amplum? It has a close resemblance.” The frond fragment above these labels is that of D. wardii . Since there is no clear indication as to who the collector of the material is, it cannot be considered as one of the syntypes.

As a result of the distinct features of this species, Tardieu-Blot (1956b: 176) transferred it to Polystichopsis (J.Sm.) Holttum , a name now considered synonymous with Arachniodes Blume ( Kramer et al. 1990: 112) .

DIAGNOSTIC FEATURES AND RELATIONSHIPS Dryopteris wardii is characterised by the near glabrous 4-pinnate fronds. Scales occur on the upper part of the stipe and lamina, and are mostly subulate and terminate in a short series of oblong cells. Hairs occurring on the lamina axes and veins are often branched and generally bear one or more glands near the base. The sporangium stalk is also haired, but the terminal cell is pyriform and glandular. In Dryopteris species where the sporangium stalk is haired, the apical cell is eglandular. The indusium, which bears hairs and glands on the laminae are also characteristic ( Fig. 26C ).

DISTRIBUTION AND HABITAT

Dryopteris wardii is known from the Seychelles only, where it is restricted to Silhouette (4°30’S, 55°15’E) and Mahé (4°45’S, 55°30’E) islands ( Fig. 29 ). Little is known about the ecology of the species, except that one of the collections was made at c. 550 m on Mahé. No recent collections of the species appear to have been made .

PUTATIVE HYBRID

Figures

FIG. 28. — Indumentum and indusium of Dryopteris wardii (Baker) Kuntze: A, stipe scale; B, indusium;C, section of indusium showing gland and hairof lamina; D, hair from abaxial lamina surface.Gardiner s.n. (BM000801018). Scale bars: A, B, 1 mm; C, D, 0.1 mm.

FIG. 26. — Indumentum of Dryopteris kilemensis (Kuhn) Kuntze:A, C, stipe scales; B, rachis scale; D, pinna-rachis scale; E, scale from abaxial lamina surface; F, G, hairs from abaxial lamina surface. Roux 2927 (NBG).2009. Scale bars: A-E, 1 mm; F, G, 0.2 mm.

FIG. 29. — Distribution of Dryopteris wardii (Baker) Kuntze in the Seychelles islands group.