Polystichum dracomontanum Schelpe


Cite taxon page as 'WFO (2020): Polystichum dracomontanum Schelpe. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-0001110875. Accessed on: 10 Jul 2020'

Diagnostic Description

Polystichum dracomontanum may be confused with P. monticola, which occurs in the same region and often in similar habitats. It can, however, be separated from it in the decumbent rhizome that produces slender stoloniferous branches, in the stipe that becomes near glabrous with age, and in the ovate lamina. Other diagnostic features are the entire rhizome paleae that evidently always terminate in a short thin-walled cell, in contrast to the often acicular apical cell in P. monticola. Paleae from the stipe, rachis, pinna-rachis and abaxial lamina surface appear to terminate more often in a thin-walled cell in contrast to those of P. monticola, where the apical cell appears to be largely acicular. The adaxial surface of the pinnules is largely glabrous but a few filiform paleae may occur proximally along the costa. These paleae always terminate in an acicular apical cell. Paleae from the abaxial surface of the pinnules largely terminate in an acicular apex, but paleae terminating in a short thin-walled cell are not unknown. The smaller paleae in P. dracomontanum are stramineous and membranous. The coriaceous lamina and somewhat revolute pinnule margins are also diagnostic. Micromorphological characters separating P. dracomontanum from other taxa are the small, almost square, adaxial epidermal cells with almost straight anticlinal walls and the almost circular stomata that are visible at a x 12 magnification.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
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    Morphology

    Terrestrial. Rhizome ascending to procumbent, with brown scales. Fronds erect to slightly arching, 2-pinnate to sometimes 3-pinnatifid, lamina lanceolate to narrowly ovate, ± 340 x 140 mm, glabrous, glossy, very dark green adaxially, matt, light green abaxially; pinnules thickly coriaceous, margins crenate, sharply serrate or aristate; rachis with red-brown, sparse, hair-like and larger scales; stipe pale green also with both hair-like and larger scales, becoming denser basally. Sporangia in circular sori with peltate, membranous indusium, 1-2 mm in diameter.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 1
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    Plants terrestrial or epilithic. Rhizome decumbent, stoloniferous, to 10 mm in diameter, densely set with roots, persistent stipe bases, and paleµ; paleµ ferrugineous, broadly attached, chartaceous, linear-attenuate, entire, the apex terminating in a small thin-walled cell, to 28 x 2 mm. Fronds closely spaced, 5-7 per plant, erect or arching, to 1.15 m long: stipe proximally castaneous, stramineous distally, adaxially sulcate, to 540 mm long x 6 mm in diameter, initially densely paleated, becoming glabrous with age, proximally with paleµ similar to those on the rhizome, the paleµ distally of two types; larger paleµ broadly attached, ferrugineous to castaneous throughout or stramineous to ferrugineous with a castaneous central region or apex, chartaceous, narrowly ovate to ovate, cordate, the margins with short, straight or curved projections, the apex often flagelliform, terminating in a thin-walled cell, to 25 x 6 mm; smaller paleµ ferrugineous to stramineous, membranous, narrowly ovate to lanceolate, cordate to cordate-imbricate, the margins closely set with short and/or long, straight or curved, often branched outgrowths, the apex flagelliform, acicular or terminating in an oblong to clavate thin-walled cell, to 11.5 x 1.8 mm: lamina 2-pinnate to 2-pinnate-pinnatifid, with up to 24 free pinna pairs, ovate, to 610 mm long: rachis stramineous to greenish, adaxialy sulcate, initially densely paleated; paleµ short-stalked, membranous, narrowly lanceolate to narrowly ovate, cordate to cordate-imbricate, the margins proximally with long and/or short, straight or curved, often branched outgrowths, the apex acicular or flagelliform and terminating in a thin-walled cell, to 7.3 x 1.6 mm: pinnµ proximally short-stalked, 1-pinnate to 1-pinnate-pinnatifid, with up to 18 free pinnule pairs, proximally widely spaced, often slightly reduced, distally often overlapping, ovate to narrowly ovate, to 105 mm long: pinna-rachis stramineous, adaxially sulcate, initially densely paleated; paleµ stramineous, membranous, narrowly oblong to narrowly triangular, cordate to cordate-imbricate, the margins proximally with long and/ or short, curved, often branched outgrowths, the apex acicular, to 9.75 x 2 mm: pinnules opposite to alternate, firmly herbaceous to coriaceous, dark green adaxially, paler abaxially, proximally widely spaced to imbricate, asymmetric, ovate to ovate-rhomboid, often somewhat falcate, acroscopically auricled, serrate to doubly-serrate, sharp-tipped to strongly aristate, the margins somewhat revolute, the proximal acroscopic pinnule usually slightly longer than the next, to 22 mm long; adaxially glabrous or with a few stramineous, membranous, filiform, acicular paleµ along proximal part of the costa, to 9.5 mm long, abaxially sparsely paleated; paleµ short-stalked, stramineous, membranous, filiform, narrowly oblong to narrowly triangular, cordate, the margins proximally with short and/ or long, straight or curved outgrowths, the apex terminating in an acicular cell or with a thin-walled cell, to 8 mm long. Venation immersed or raised. Sori circular, c. 2 mm in diameter, terminal or near-terminal on abbreviated vein branches, uniseriate, discrete to confluent at maturity: sporangium with 10-(13)-21 indurated annulus cells; stalk eglandular: indusium ferrugineous to stramineous, chartaceous, persistent, peltate, circular, with or without central processes, repand to weakly erose, the maximum radius 0.63-(0.81)-1.09 mm. Spores 64 per sporangium, brown, the perispore globose or folded to form inflated or narrow reticulate ridges, minutely and sparsely perforated, the ridges and areas between echinate to echinulate, the exospore 25-(54.24)-70 x 28-(41.04)-58 µm.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
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    Rhizome creeping, c. 6 mm in diameter, set with linear, brown, subentire rhizome-scales, forming tufted erect plants at intervals. Fronds rigidly erect; stipe darkened towards base, set with linear, ferrugineous scales c. 25 mm long basally and, above them, atrocastaneous, ovate-lanceolate scales with pale margins; lamina thickly coriaceous, broadly lanceolate, c. 340 x 140 mm, 2-pinnate, rarely 3-pinnatifid, acute apically, truncate basally; pinnae sharply serrate or biserrate with acuminate apices; pinnules falcate, auriculate, with blunt or sharp aristae, subglabrous above, set with narrow scales along veins below becoming glabrous with age; venation obscure; rhachis and secondary rhachises set with sublinear scales in sulca and with pale, ovate-attenuate, very fimbriate scales below, becoming glabrous with age. Indusium brown, nitid, erose to subentire, usually with central processes, c. 1-2 mm in diameter.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 3
    • ]. 

    Habitat

    Mesic Grassland. Forest margins and montane grassland.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 1
    • ]. 

    It occurs at elevations ranging from 1675 to 2745 m. Within this distribution the species is restricted to two vegetation types as defined by Acocks (1988). Along the high Drakensberg escarpment it occurs in Themeda-Festuca Alpine Veld that receives an annual precipitation of 600-1900 mm. Polystichum dracomontanum occurs in grasslands and scrub forests associated with this vegetation type. To the north, along the escarpment between the Free State and KwaZulu-Natal, dominated by the Clarens Sandstone formation, the species occurs in sheltered forests of the Highland Sourveld type. Precipitation in this region measures between 750 and 1500 mm. The habitat includes streambanks, boulder bases, screes and scrub, and rarely also forests. Polystichum dracomontanum prefers moist cool slopes in shaded gullies and kloofs where it often forms large stands. At certain sites the species is subjected to regular veld fires, but this appears to have no adverse effect on plants.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
    • ]. 

    1600 and 3000 m altitude. Forming large colonies on open slopes.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 3
    • ]. 

    Distribution

    Polystichum dracomontanum is largely confined to the northern Drakensberg Escarpment between Lesotho and KwaZulu-Natal where it occurs on both the lower Clarens Sandstone and the upper basalt formations. The species also occurs further northwards along the escarpment between the Free State and KwaZulu-Natal. Isolated populations have also been reported from the Mafeteng District in southeastern Lesotho.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 2
    • ]. 

    The Natal Drakensberg.

  • Provided by: [B].e-Flora of South Africa
    • Source: [
    • 3
    • ]. 

      Bibliography

    • 1 Klopper, RR. 2017. Pteridophyta. In: E Retief & NL Meyer (eds), Plants of the Free State: Inventory and identification guide. Strelitzia 38: 114 - 143. South African National Biodiversity Institute, Pretoria.
    • 2 Roux, JP. 2000. The genus Polystichum (Dryopteridaceae) in Africa. Bull. Nat. Hist. Mus. London, Bot. 30(2): 33 - 79. Permission was granted to SANBI by The Bulletin of Natural History Museum, Natural History Museum London. This material may not be reproduced or transferred to any other publication without written permission from the copyright holder.
    • 3 Schelpe, EACLE; Anthony, NC. 1986. Pteridophyta. In: O.A. Leistner (ed.). Fl. S. Africa : 1 - 278.

     Information From

    Dryopteridaceae
    World Flora Online Data. 2017.
    • A CC0 1.0 Universal (CC0 1.0).
    e-Flora of South Africa
    e-Flora of South Africa. v1.21. 2018. South African National Biodiversity Institute. http://ipt.sanbi.org.za/iptsanbi/resource?r=flora_descriptions&v=1.21
    • B All Rights Reserved
    World Flora Online consortium
    http://www.worldfloraonline.org/organisation/WFO
    World Flora Online Data. 2018.
    • C CC0 1.0 Universal (CC0 1.0).