Polystichum kalambatitrense Tardieu

Roux, Jacobus P., 2001, A review of the fern genus Polystichum (Pteropsida: Dryopteridaceae) in Madagascar and the Mascarene region, Adansonia (3) 23 (2), pp. 265-287 : 272-275

3. Polystichum kalambatitrense Tardieu

Notul. Syst. (Paris) 15: 165 (1956); Tardieu, in Humbert, Fl. Madag. , fam. 5: 320 (1958). — Type: Humbert 11914, Madagascar, massif du Kalambatitra, Mt. Analasitendrika, 1650-1800 m (holo-, P!).

Plants terrestrial. Rhizome decumbent, to 10 mm in diameter, beset with roots, closely spaced persistent stipe bases and paleae, the paleae ferrugineous, membranous to chartaceous, broadly attached, lanceolate to narrowly ovate, cordate, the margins closely beset with short straight or curved outgrowths, the apex terminates in a long flagelliform cell, to 10 × 4 mm. Fronds crowded, 4 or 5 per plant, suberect to arching, to 1.11 m long; stipe proximally castaneous, stramineous higher up, adaxially sulcate, to 455 mm long, to 5 mm in diameter, moderately beset with conspicuously larger and smaller paleae, the larger paleae ferrugineous, membranous, broadly attached, ovate to broadly ovate, cordate to cordate-imbricate, the margins closely beset with small curved outgrowths, the apex terminates in a long flagelliform cell, to 17 × 8 mm, the smaller paleae ferrugineous to castaneous, membranous, sessile or short-stalked, narrowly lanceolate to narrowly ovate, cordate-imbricate, the margins proximally closely beset with long, simple or branched, flagelliform outgrowths, distally the outgrowths become more widely spaced and rigid, pointing basally or apically, the apex terminates in a long acicular or flagelliform cell, or a small thin-walled cell, to 6.8 × 0.9 mm; lamina 1-pinnate, with up to 28 pairs of stalked pinnae, herbaceous to coriaceous, ovate-lanceolate, to 650 × 230 mm; rachis stramineous, adaxially sulcate, moderately to densely paleated, the paleae ferrugineous to castaneous, membranous, broadly attached or short-stalked, lanceolate to narrowly triangular, cordate or cordate-imbricate, the margins proximally closely beset with long, simple or branched flagelliform outgrowths, distally the outgrowths are shorter, more widely spaced and curved or straight, the apex terminates in a long flagelliform cell, to 8 × 2 mm; pinnae opposite to alternate, proximally widely spaced, more closely spaced distally but never overlapping, linear-attenuate to narrowly oblongattenuate, proximally short-stalked, broadly attached towards the lamina apex, inaequilaterally truncate, with or without an acroscopic auricle, the auricle obtuse, often incised near to the costa, then broadly elliptic, the margins proximally subentire, serrate to serrate-dentate distally, or obtusely lobed, the lobes serrate-dentate, dull green adaxially, slightly paler abaxially, to 135 mm long, to 18 mm wide, adaxially sparsely beset with taeniform paleae along the costa, to 8.5 mm long; abaxially sparsely paleated largely along the costa, the paleae ferrugineous to stramineous, membranous, short-stalked, narrowly triangular; narrowly trullate or narrowly triangular-hastate, cordate, proximally with a few short, rigid outgrowths or with a few long flagelliform outgrowths, to 5.5 mm long; costa flexuose distally, sulcate adaxially, pronounced abaxially. Venation free, evident abaxially and adaxially. Sori circular, to 2 mm in diameter, terminal or near-terminal on abbreviated vein branches, near the costa on smaller pinnae; sporangium with 11(-13-)13-indurated annulus cells; indu- sium ferrugineous to castaneous, persistent, repand or unequally lobed, maximum radius 0.36(-0.43-) 0.58 mm; spores brown, the perispore forms a close reticulum of inflated ridges, the ridges crested, the ridges and areas between echinulate, minutely perforated. Chromosome number unknown. — Figs. 3H, I , 4.

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MATERIAL EXAMINED. — MADAGASCAR: Humbert 11914, massif du Kalambatitra, Mt. Analasitendrika , 1650-1800 m ( P), type ; Humbert 12158, massif de l’Ivakoany, 1250-1550 m ( BR, P) .

DIAGNOSTIC FEATURES AND RELATIONSHIPS. — TARDIEU - B LOT (1956a) suggested that Polystichum kalambatitrense was closely related to P. falcinellum (Sw.) C. Presl from Madeira and P. macleae (Baker) Diels from South Africa. Although P. falcinellum is a species with 1-pinnate fronds, there appears to be no affinity between these taxa as it differs markedly from P. kalambatitrense in indusium and paleae morphology. Polystichum kalambatitrense appears to be related to P. macleae because of the similarity in the size and morphology of the indusia and paleae. Unlike P. macleae , where some proximal marginal outgrowths of the paleae terminate in a small thin-walled cell, the marginal outgrowths in P. kalambatitrense terminate either in an acicular cell or a long flagelliform cell. In P. kalambatitrense the stipe paleae rarely terminate in a thin-walled cell whereas in P. macleae they regularly do so. The epidermal cell length and the guard cell length are larger for P. kalambatitrense (50(-56.8-)70 µm) than for P. macleae (32(-46.03-)60 µm).

VARIATION. — Polystichum kalambatitrense shows some variation in pinna morphology. In some plants the acroscopic auricle on the proximal pinnae is incised near the costa whereas in others the pinnae are barely acroscopically developed. The pinna margins also vary from entire to proximally slightly repand to serrate, or obtusely lobed with the margins of the distal lobes serratedentate.

DISTRIBUTION AND ECOLOGY. — Polystichum kalambatitrense is endemic to Madagascar and

appears to be restricted to the southern part of the central mountain range. The species is confined to forests along the Kalambatitra mountain range, where on Mount Analatsitendrika it grows at elevations between 1650 and 1800 m. To the south, on the l’Ivakoany mountain range, the species grow at elevations between 1250 and 1550 m.

Figures

Fig. 3. — Stipe and lamina paleae in Polystichum species. — Polystichum ammifolium: A, stipe palea, Boivin 822 (B); B, lamina palea (adaxial surface), Rakolomalala s.n. (P); C, basal part of B showing the cellular structure. — Polystichum crinulosum: D, stipe palea, s.coll. s.n. (P); E, apex of D showing the cellular structure; F, rachis palea, s.coll. s.n. (P); G, apex of F showing the cellular structure. — Polystichum kalambatitrense: H, stipe palea. Humbert 12158 (P); I, lamina palea (abaxial surface), Humbert 11914 (P). — Polystichum luctuosum: J, stipe palea. Roux 2268 (NBG); K, lamina palea (abaxial surface), McDonell 34 (BM).

Fig. 4. — Polystichum kalambatitrense: A, basal part of the lamina; B, rhizome; C, abaxial surface of a fertile pinna. Humbert 11914 (P).