Nepenthes malayensis
Synonymy
Nepenthes malayensis in Kew Bull. 75(4) article no. 63: 3. 2020 [The specific epithet malayensis is derived from the word Malaya — the classical name for Peninsular Malaysia — signifying that the species was discovered in Peninsular Malaysia and currently acknowledged to be endemic to the eastern part of this regionB]. sec. Amin Asyraf Tamizi, Mohd Norfaizal Ghazalli, Dome Nikong, Edward Entalai Besi, Muhamad Ikhwanuddin Mat-Esa, Anuar Rasyidi Mohd-Nordin, A. Latiff & Mohamad Alias Shakri 2020
- Type: "Malaysia, Terengganu, East Coast Range (Banjaran Pantai Timur), Amin Asyraf, Mohd Norfaizal, Dome, Edward & Muhamad Ikhwanuddin MDI 12422 (holotype MDI!; isotypes K!, KEP!)"1
- 1. Amin Asyraf Tamizi, Mohd Norfaizal Ghazalli, Dome Nikong, Edward Entalai Besi, Muhamad Ikhwanuddin Mat-Esa, Anuar Rasyidi Mohd-Nordin, A. Latiff & Mohamad Alias Shakri 2020: Nepenthes malayensis (Nepenthaceae), a new species of carnivorous pitcher plant from Peninsular Malaysia. – Kew Bull. 75(4) article no. 63. http://doi.org/10.1007/s12225-020-09918-z
Description
Facultative lithophytic climber that can grow up to 1.5 – 1.8 m tall, with the base of the plant anchored on organic matter accumulated on top of granite-type boulders. Climbing stems broadly angular and broadly cylindrical towards the shoot, 0.5 – 0.7 cm diam.; internodes 8 – (9.5) – 10.8 cm. Leaves thickly coriaceous, sessile, linear to oblong-lanceolate, 21 – (23) – 25 cm long and 4 – (5.2) – 5.6 cm wide, apex retuse, base clasping stem for about ½ of its circumference; longitudinal veins 2 – 4 on each side of the midrib; unicellular trichomes present on the abaxial side of the midrib (Fig. 8C); lamina margin curving towards the abaxial epidermis, slightly wavy on the adaxial surface and several blunt projections on the abaxial epidermis surface (Fig. 8E); midrib with light pinkish hue on the upper adaxial and abaxial surface of lamina blades. Lower pitchers lower ½ – 1/3 slightly ovoid, contracting above hip, hip located anywhere from ½ to ¾ away from peristome, upper part slightly ovoid or sometimes cylindrical, contracting slightly below peristome; 9 – 11 cm long and 4 – 5 cm wide; coriaceous in texture; arising abruptly from the tendril, frequently attached at the side of the pitcher; tendrils 15 – 16 cm long without coil formation; with two fringed wings, 5 – 6 mm wide, with unicellular hair elements (3 – 4 mm long); mouth sub-ovate to ovate; peristome loosely cylindrical, 2 – 4 mm wide; teeth absent; lid broadly cordate to orbiculate, with a midline groove at the centre, 3.5 cm long and 4.3 cm wide, base cordate, underside hairs absent; nectar glands observed only on the lower surface of the lid, ~85 – 110 glands scattered in an ovate shape 1.5 – 2.8 cm wide, getting larger and denser towards the base of the lid, observed as a red-black dot formation, dimorphic (mixture of circular and oval glands), 10 – 50 μm diam. (Fig. 9); spur sometimes branched when it is ≤ 3 mm long; pitchers green-yellowish throughout or sparsely blotched with red specks in matured pitchers, heavily overlain with red blotches/reticulation on the inner surface of pitcher from peristome to hip level, peristome green-yellowish and striped with red bands; lid green-yellow in colour. Upper pitchers lower 1/3 broadly infundibular or ovoid, constricted above hip, upper part broadly cylindrical or slightly ovoid, contracting immediately below peristome; 17 – 22.5 cm long and 7 – 8 cm wide; arising gradually from the tendril part; tendrils with coil in the middle, 17 – (19) – 20 cm long; wings absent and reduced to ribs; peristome 6 – 8 mm wide, loosely cylindrical at the front, slightly expanded and angular at lateral sides; spur semi erect, unbranched, simple, 0.6 – 1.1 cm long; lid broadly orbiculate to rounded, 4.3 × 5.5 cm, base cordate; all other parts similar to those of the lower pitchers; peristome dark reddish to brownish throughout with striking green-yellowish bands, lid light green-yellow in colour. Male inflorescence (only known from a photograph) pedicels long, double-flowered; four tepals, tepals broad ovate without nectar glands; all parts of the inflorescence and tepals yellowish-brown; bracteole absent. Female inflorescence currently unknown and not observed during sampling. Indumentum present mostly on the stems as simple unicellular brownish hairs, less than 1 mm long. Colour of the dried specimen light brown (lamina, stem and pitcher)A
Notes
A male inflorescence of Nepenthes malayensis is documented here but the female part remains undescribed. However, the floral features do not always present a barrier in declaring new Nepenthes species as seen in three recently described taxa from the Philippines: N. justinae Gronem., Wistuba, Mey & V.B.Amoroso (unknown male inflorescence), N. cornuta Marwinski, Coritico, Wistuba, Micheler, Gronem., Gieray & V.B.Amoroso (unknown female inflorescence) and N. talaandig Gronem., Coritico, Wistuba, Micheler, Marwinski, Gieray & V.B.Amoroso (unknown female inflorescence) (Gronemeyer et al. 2014, 2016). The current description of lower pitchers of N. malayensis is limited to relatively small specimens since larger pitchers were not readily available during our visit to the habitat. Still, the lower pitchers were growing on the same mature stems that were producing large upper pitchers; hence, their characters are just as reliable to be used for identification. As stated, the new species was observed in highland habitat that experiences high humidity and temperature drop (at night) down to ~12°C. Despite this, our preliminary investigation showed that plants grown ex situ under lowland conditions were able to produce pitchers that do not indicate any morphological differences as compared to plants observed in situ, except for having less prominent peristomal bands.
The presence of peristome teeth and bristles underneath the lid in Nepenthes macfarlanei make it a much more distant taxon than N. sanguinea to N. malayensis. Nepenthes sanguinea shares some morphological similarities with the new species such as angular stem, peristome lacking teeth, orbiculate lid, lid underside lacking hairs and hip positioned at ½ – 1/3 from the base of the pitcher; hence, it was used primarily in this work for comparison over N. macfarlanei, N. ramispina and N. gracillima.
Phylogeny of all peninsular Nepenthes using ITS sequences separated them into two major groups as depicted in Fig. 6, which is consistent with Bunawan et al. (2017). As expected, N. malayensis was positioned under the highland and intermediate highland (H/IH) clade and together with N. benstonei they formed a basal group to four defined highland taxa namely N. sanguinea, N. macfarlanei, N. gracilis and N. gracillima. Nepenthes alba Ridl. is shown in the figure as the second basal taxon to the H/IH clade after N. albomarginata T.Lobb ex Lindl. even though the former species is considered a taxon limited to elevations higher than 1500 m a.s.l. (Ridley 1908; Clarke & Lee 2012). This reflects the resolution of a certain taxon for highland vs intermediate highland is relatively poor for the peninsular H/IH clade when using ITS. Nevertheless, our ex situ living specimens kept under lowland conditions suggest that N. malayensis is an intermediate highland taxon and a rather resilient plant. This will further aid us in formulating future plans to step up conservation for this rare species.
As a conclusion, analyses of morphology and leaf anatomy of Nepenthes malayensis have established this highly endangered pitcher plant as a new species from Peninsular Malaysia and this is further resolved through phylogenetic inference. The new documentation of such an iconic plant is considered very important to ensure the survival of the species and it is hoped that this discovery will instigate more conservation efforts in the area to further preserve the N. malayensis population from potential disturbances.A
The presence of peristome teeth and bristles underneath the lid in Nepenthes macfarlanei make it a much more distant taxon than N. sanguinea to N. malayensis. Nepenthes sanguinea shares some morphological similarities with the new species such as angular stem, peristome lacking teeth, orbiculate lid, lid underside lacking hairs and hip positioned at ½ – 1/3 from the base of the pitcher; hence, it was used primarily in this work for comparison over N. macfarlanei, N. ramispina and N. gracillima.
Phylogeny of all peninsular Nepenthes using ITS sequences separated them into two major groups as depicted in Fig. 6, which is consistent with Bunawan et al. (2017). As expected, N. malayensis was positioned under the highland and intermediate highland (H/IH) clade and together with N. benstonei they formed a basal group to four defined highland taxa namely N. sanguinea, N. macfarlanei, N. gracilis and N. gracillima. Nepenthes alba Ridl. is shown in the figure as the second basal taxon to the H/IH clade after N. albomarginata T.Lobb ex Lindl. even though the former species is considered a taxon limited to elevations higher than 1500 m a.s.l. (Ridley 1908; Clarke & Lee 2012). This reflects the resolution of a certain taxon for highland vs intermediate highland is relatively poor for the peninsular H/IH clade when using ITS. Nevertheless, our ex situ living specimens kept under lowland conditions suggest that N. malayensis is an intermediate highland taxon and a rather resilient plant. This will further aid us in formulating future plans to step up conservation for this rare species.
As a conclusion, analyses of morphology and leaf anatomy of Nepenthes malayensis have established this highly endangered pitcher plant as a new species from Peninsular Malaysia and this is further resolved through phylogenetic inference. The new documentation of such an iconic plant is considered very important to ensure the survival of the species and it is hoped that this discovery will instigate more conservation efforts in the area to further preserve the N. malayensis population from potential disturbances.A
Conservation
The new species is currently known only from a single population of five mature clumps and a few plantlets. The type collection and observed individuals indicated that the new species is not abundant compared to other sympatric species as it depends on rock formations to grow and fully establish. Other occurrences of the species in different areas, or localities, are currently unknown, but it is postulated that this species may only be found confined to this original habitat (<6.0km2). Hence, the new species is treated as endemic to Terengganu and Critically Endangered (CR) under criterion D according to the IUCN Red List Categories and Criteria (IUCN 2012). The area had experienced logging in the past which has regenerated. This could be the likely cause of the diminished population size and scattered individuals.A
Distribution (General)
Only known from Peninsular Malaysia: Terengganu, East Coast Range (Banjaran Pantai Timur).A
Habitat
Lower boundary of cloud forest, 800 – 1000 m a.s.l., mildly disturbed forest. The species grows vigorously on rock formations near hill slopes and is classified as a facultative lithophyte as mature plants (five individual clumps) were observed growing on accumulated organic mass (tree fibrous roots, accumulation of dead leaves and mosses) on top of granite boulders, and three smaller plants growing on arboreal mosses as epiphytes. Not a single plant was observed to be growing on the ground/soil. Plants grow well in both exposed and partially shaded areas and trap insects, the remains of which were observed in pitcher sediments. The species is presently known from a single population within a small area with mature individual clumps growing apart from each other depending on the location of the boulders. Other sympatric species occurring in the area included N. ampullaria Jack, N. gracilis Korth., N. cf. benstonei, N. macfarlanei and an array of different Nepenthes nothotaxa (natural hybrids). A few individuals that resemble N. malayensis were also observed; however, the plants had an elliptical lid (instead of broad ovate) and green reddish pitchers heavily overlain with speckles. These could be the hybrids of the new species with N. macfarlaneiA
Bibliography
A. Amin Asyraf Tamizi, Mohd Norfaizal Ghazalli, Dome Nikong, Edward Entalai Besi, Muhamad Ikhwanuddin Mat-Esa, Anuar Rasyidi Mohd-Nordin, A. Latiff & Mohamad Alias Shakri 2020: Nepenthes malayensis (Nepenthaceae), a new species of carnivorous pitcher plant from Peninsular Malaysia. – Kew Bull. 75(4) article no. 63. http://doi.org/10.1007/s12225-020-09918-z