REINWARDTIA Vol. 21. No. 1. pp: 19‒23 DOI: 10.55981/reinwardtia.v21i1.4306 19 NEPENTHES HARAUENSIS, A NEW SPECIES OF NEPENTHACEAE FROM WEST SUMATRA Received January 23, 2022; accepted April 18, 2022 HERNAWATI Faculty of Forestry, Muhammadiyah University of West Sumatra, Jln. Pasir Kandang No. 4, Pasie Nan Tigo, Koto Tangah, Padang, 25172, Indonesia. E-mail: sinanalep@hotmail.com ROBI SATRIA Harau Nursery, Lembah Harau, Payakumbuh, 26271, Indonesia. E-mail: harauorchids4523@gmail.com CH’IEN C. LEE Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia. E-mail: chien@chienclee.com ABSTRACT HERNAWATI, SATRIA, R. & LEE, C. C. 2022. Nepenthes harauensis, a new species of Nepenthaceae from West Sumatra. Reinwardtia 21(1): 19‒23. — A new species of Nepenthes (Nepenthaceae) from the Harau region of West Sumatra is described as Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee. This species shares specific characteristics with both N. bongso and N. singalana but is unique in its thickly coriaceous and petiolate leaves, which are elliptic-oblong and have a distinctly peltate tendril insertion. Key words: Har au, Nepenthaceae, Nepenthes, Sumatr a. ABSTRAK HERNAWATI, SATRIA, R. & LEE, C. C. 2022. Nepenthes harauensis, jenis baru Nepenthaceae dari Sumatra Barat. Reinwardtia 21(1): 19‒23. — Jenis baru Nepenthes (Nepenthaceae) dari kawasan Harau Sumatra Barat dipertelakan sebagai Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee. Jenis ini mempunyai kemiripan karakter morfologi dengan N. bongso dan N. singalana tetapi memiliki keunikan dalam tekstur daun yang tebal dan kaku, berbentuk jorong yang melonjong, mempunyai tangkai daun dan memiliki sisipan sulur yang jelas menyerupai perisai. Kata kunci: Har au, Nepenthaceae, Nepenthes, Sumatr a. INTRODUCTION Nepenthes (Nepenthaceae) belongs to the group of carnivorous pitcher plants and is one of the groups with the highest number of species consisting of at least 160–180 species worldwide (Murphy et al., 2020). The island of Sumatra has long been recognized as one of the most diverse regions for the genus Nepenthes. Following Clarke’s 2001 regional monograph, which listed 29 Nepenthes species for the island, eight additional taxa, all endemic, have been described: N. izumiae (Clarke et al., 2003), N. rigidifolia (Akhriadi et al., 2004), N. jamban and N. lingulata (Lee et al., 2006), N. flava (Wistuba et al., 2007), N. naga (Akhriadi et al., 2009), N. putaiguneung (Metusala et al., 2020), and N. longiptera (Victoriano, 2021). The steady rate of these discoveries is likely due to increased exploration of previously inaccessible regions of Sumatra. It suggests that the full diversity of Nepenthes on the island is far from being fully resolved. In 2015, Robi Satria made the first observations of an unidentified Nepenthes species in Harau, West Sumatra. Researchers from the Nepenthes- Team Padang (NP-Team Padang) visited the same locality in 2016 but found only a few individual plants that did not have pitchers. In July and September 2021, NP-Team Padang conducted repeat visits to this site and eventually successfully procured complete specimens of this Nepenthes that possessed both upper and lower pitchers. Upon detailed examination and comparisons with other Sumatran Nepenthes, it was clear that this represented a distinct taxon described herein as a new species. MATERIALS AND METHODS The fieldwork was carried out in July and September 2021 in Harau, West Sumatra. The locality and population distribution can be seen in Fig. 1. Morphological characters of N. harauensis were photographed and noted from the living plant in the wild. Measurements were made using a ruler and a Vernier calliper. Herbarium specimens were prepared and deposited at Herbarium Universitas Andalas (ANDA). The morphological characters http://dx.doi.org/10.14203/reinwardtia.v19i1.3850 mailto:chien@chienclee.com REINWARDTIA 20 [VOL.21 of N. harauensis were then compared with the collection of specimens of N. bongso, N. ovata, and N. singalana stored in the Herbarium of Andalas University (ANDA) Padang. RESULTS AND DISCUSSION Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee spec. nov. — TYPE: INDONESIA, West Sumatra, Lima Puluh Kota, Harau, growing terrestrially on shady sandstone clift, 1,100–1,400 m asl, flowering and fruiting, 22 September 2021, Nepenthes-Team Padang (Hernawati, Havid, Ihsan), NPT 220921-1 (holotype ANDA!, isotype BO!). Fig. 2. Nepenthes harauensis has several morphological characteristics similar to N. bongso, but the pitcher shape is more like the N. singalana. The most prominent distinguishing character is the thick and stiff coriaceous leaf structure, the peltate tendril insertion, and the sheath-like petiole, which clasps the stem for ¾– ½ of its circumference. Terrestrial climber up to 3 m tall. Rosette not found. Short shoots cylindrical 0.8–1.0 cm with congested leaves (2 per cm of the stem), internodes obscured. Climbing stem angular 0.5 cm, internodes 4.0–6.9 cm long. Leaves of short shoots thickly and stiffly coriaceous, petiolate; petiole 2.0–5.9 cm long, sheath-like, clasping stem for ¾ circumference; lamina elliptic to oblong, 9.5–15.9 × 5.2–6.7 cm, apex obtuse to truncate, gradually attenuate to the base; midrib flattened above and raised beneath, longitudinal veins 2 on each midrib, inconspicuous, pinnate veins inconspicuous; tendrils 27.0–49.5 cm long, peltate, ca. 0.4 cm from the apex. Leaves of climbing stem same as those of short shoots but petiole 3.0–4.0 cm long, clasping stem for ½ circumference and not decurrent; lamina elliptic to oblong or slightly spathulate, 8.5–10.0 × 3.5–4.0 cm; tendrils sub-apical close to the apex, 12.0–29.0 cm long with 2–3 curls in the middle. Lower pitchers originating abruptly from the tendril, ovoid 1/3– 1/2 in the lower half (6.1–9.0 × 3.7–5.2 cm), constricting to the hip, then cylindrical toward the mouth (8.5–12.8 × 2.7–3.9 cm); inner surface pale green on the glandular zone, pale green with dark red blotches on the waxy portion extending from the constriction of the hip to the top of the pitchers; two fringed wings present on the front of the pitcher, 2.9–4.4 × 0.1–0.2 cm, run from the mouth to the bottom, with fringed elements 0.2– 0.5 cm long; mouth ovate, oblique throughout, elongated into a short neck (≤ 2 cm) toward the lid; peristome more or less cylindrical, narrow at the front (≤ 0.6 cm), widening toward the rear (≤ 1.4 cm), ribs distinct, ≤ 0.1 cm apart, raised ≤ 0.1 cm, inner margin ending in teeth ca. 0.2 cm long; lid cordate to orbicular 4.1–5.1 × 3.6–5.1 cm, apex obtuse, with rounded protrusions, ca. 0.2 cm thickness on the lower surface, spaced ca. 0.4 cm from the lid tip, glands more or less evenly distributed across the undersurface although larger, and more densely packed along the midrib; spur simple ≤ 0.2 cm long. Upper pitchers originating laterally from the tendril, narrowly ovoid in the lower third (4.3–6.0 × 2.4–2.7 cm), constricting to Fig. 1. Distribution of Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee HERNAWATI et al.: Nepenthes harauensis, a new species of Nepenthaceae from West Sumatra 2022] 21 the hip, then cylindrical and widening toward the mouth (8.2–10.7 × 1.2–3.2 cm); inner surface same as that of the lower pitcher but the red blotches in the waxy zone are fewer and smaller; wings reduced to ribs; mouth ovate, oblique throughout, elongated into a short neck (≤ 1 cm), peristome same of those lower pitcher, but narrower (≤ 0.2 cm at the front and ≤ 0.5 cm at the rear) with three small lobes on each side, teeth ≤ 0.1 cm long; lid same of those lower pitcher, but smaller (3.7–4.8 × 2.8–4.0 cm); spur simple ≤ 0.7 cm long. Male inflorescence a raceme, peduncle to 11.0–13.0 cm long, rachis 10.0–12.0 cm, pedicels 0.8–1.1 cm long, each bearing a single flower with a filiform bracteole 0.5 × 0.1 cm, spaced ca. 0.3 cm from the base of the pedicel, tepal broad ovate 0.5–0.6 × 0.3 cm, pale green, staminal column ≤ 0.3 cm long. Female inflorescence is similar to the male but with a longer peduncle (19.5 cm long). Fruits cap- sule 1.1–1.6 × 0.2–0.4 cm. Indumentum, all parts of the plant are glabrous. Colour of living specimens: stem and midrib pale green, occasionally purplish red; leaves light green above, pale green below; lower pitcher reddish- green with dark red blotches to dark red; upper pitcher pale green; peristome dark red on a lower pitcher and pale green with the dark red stripe on the upper pitcher; inflorescence pale green. Distribution. Nepenthes harauensis is only known from the type locality in Harau, West Sumatra, Indonesia. Habitat. Gr owing ter r estr ially on shady cliffs of the stunted forest of the sandstone hills around Harau. Numerous canyons in Harau are formed among flat-topped sandstone outcrops with near- vertical walls. Tropical lowland evergreen rain forests grow at the bases and summit of the outcrops. Vegetation and open areas which result Table 1. Morphological characters of N. harauensis, N. bongso, N. ovata, and N. singalana Characters N. harauensis N. bongso N. ovata N. singalana Stem Cylindrical to angular Cylindrical to angular Cylindrical Cylindrical, occasionally angular Internode Obscured on the short shoots; 4.0–6.9 cm long on the climbing stems ≤ 15 cm long on the climbing stems ≤ 15 cm long on the climbing stems ≤ 15 cm long on the climbing stems Leaves Stiffly coriaceous, petiolate, clasping the stem, lamina elliptic to oblong Coriaceous, sessile, lamina spathulate to lanceolate Coriaceous, sessile to broadly sub-petiolate, lamina lanceolate- spathulate Thinly coriaceous, sessile, lamina lanceolate to lanceolate-spathulate Tendril insertion Peltate/sub-apical Sub-apical Apical Apical Longitudinal veins 2 on each side of the midrib 2–5 on each side of the midrib 3 on each side of the midrib 3–6 on each side of the midrib Lower pitcher Ovoid then cylindrical on the upper part Broadly ovoid throughout Broadly ovoid throughout Narrowly ovoid then cylindrical on the upper part Peristome Cylindrical, widening toward the rear Cylindrical or flattened expanded toward the rear Flattened expanded toward the rear Cylindrical, widening to the rear, expanded to the inside Lid Cordate to orbicular with a simple thickened bump near the apex Cordate to orbicular with a simple, bifid, or grossly appendage near the apex Ovate with a pro- nounced appendage near the basal part Slightly cordate to orbicular, no appendage Upper pitcher Narrowly ovoid cylindrical and widening above Infundibular Cylindrical then infundibular above Narrowly ovoid and cylindrical above Inflorescence 1-flowered 1-2 flowered 1-flowered 1-flowered REINWARDTIA 22 [VOL.21 from their structure provide important habitat for several Nepenthes species, including N. adnata, N. albomarginata, N. eustachya, N. longifolia, and N. tenuis. Nepenthes harauensis generally grows on cliffs above an altitude of 1,100 m asl. Etymology. The specific name refers to the place “Harau,” a sub-district of Lima Puluh Kota Regency. Conservation status. Based on observations, there are at least six populations in the type locality with an estimated number of young plants <100 individuals. Despite having many individuals, this species rarely produces pitchers, especially the upper pitchers. Habitats of N. harauensis are located in protected forest areas, so at this time, deforestation is not a serious threat to this species. Illegal collection by plant collectors can be a potential threat if there is no early management of the species. Further observations are still needed to assess the conservation status of N. harauensis. Notes. This species is most readily distinguished from all other Sumatran Nepenthes by its unique combination of morphological characters. Particularly unusual are the strongly petiolate leaves, a feature not seen in any other Sumatran montane Nepenthes. The peltate tendril insertion is also unusual in the genus Nepenthes. In Sumatra, it is only shared with N. rigidifolia and N. bongso. Based on the characteristics of the pitchers, N. harauensis is appeared to be most closely allied to N. bongso, N. ovata, and N. singalana, none of which occur in the Harau region. From N. bongso and N. ovata, it can be distinguished in having its pitchers either abruptly cylindrical or slightly expanded in their upper half (vs being ovoid or infundibular throughout). From N. singalana, it differs in having a distinctly rounded, thickened protrusion on the undersurface of the apex of the lid. Moreover, a peristome that does not expand on its inner edge. These differences are outlined in Table 1. Fig. 2. Nepenthes harauensis Hernawati, R.Satria & Chi.C.Lee. A. Population of N. harauensis in the habitat. B. Habit of the short shoots. C. Leaf apex showing peltate tendril insertion. D. Lower pitcher. E. Upper pitcher. F. Male inflorescence. G. Fruits. H. Glandular zone on the lid. From Nepenthes-Team Padang (Hernawati, Havid, Ihsan) NPT 220921-1. Photos by Robi Satria and Havid Ramadhan. HERNAWATI et al.: Nepenthes harauensis, a new species of Nepenthaceae from West Sumatra 2022] 23 Although hybridization is a frequent occurrence among Nepenthes, the possibility of a hybrid origin for N. harauensis is unlikely, given that there are no putative parental species in the Harau region that could contribute morphological features that are distinct for this species. With the addition of N. harauensis, 11 Nepenthes species have now been recorded within the Harau region of West Sumatra, making it one of the most diverse localities for this genus. Although most of endemic Nepenthes species from Sumatra are restricted to the upper montane mossy forest of the Barisan Mountains, typically above 2,000 m, the highest peak within Harau reaches only 1,460 m. Despite this considerably lower elevation, the stunted forest of the sandstone hills around Harau may mimic certain habitat conditions of higher mountains, making it possible for montane Nepenthes to occur at lower altitudes. The presence of N. inermis evidences this, a species typically restricted to higher summits, found to grow near N. harauensis. Other specimens examined. INDONESIA, Sumatra, West Sumatra, Lima Puluh Kota, Harau, 1,100–1,400 m asl., 06 July 2021, Nepenthes- Team Padang (Hernawati, Havid, Ihsan), NPT 060721-1 (ANDA). ACKNOWLEDGEMENTS We would like to thank the curator of the Anda- las University Herbarium (ANDA) for handling and storing the specimens. Thanks to WWF EFN Russel E Train Education for Nature Program for Research Grants. The first author would like to thank Prof. Ervizal A. M. Zuhud, Prof. Lilik Budi Prasetyo, and Dr. Rinekso Soekmadi as the research supervisors. We also thank the local people who have helped with the fieldwork. REFERENCES AKHRIADI, P., HERNAWATI & TAMIN, R. 2004. A new species of Nepenthes (Nepenthaceae) from Sumatra. Reinwardtia 12(2): 141–144. AKHRIADI, P., HERNAWATI, PRIMALDHI, A. & HAMBALI, M. 2009. Nepenthes naga, a new species of Nepenthaceae from Bukit Barisan of Sumatra. Reinwardtia 12(5): 339– 342. CLARKE, C. 2001. Nepenthes of Sumatra & Peninsular Malaysia. Natural History Publication (Borneo). Kota Kinabalu. Sabah. CLARKE, C., DAVIS, T. & TAMIN, R. 2003. Nepenthes izumiae (Nepenthaceae): A new species from Sumatra. Blumea 48: 179–182. LEE, C. C., HERNAWATI & AKHRIADI, P. 2006. Two new species of Nepenthes (Nepenthaceae) from North Sumatra. Blumea 51: 561–568. METUSALA, M., AL FARISHY, D. D. & JEBB, M. 2020. Nepenthes putaiguneung (Nepenthaceae), a new species from the highland of Sumatra, Indonesia. Phytotaxa 454(4): 285–292. MURPHY, B., FOREST, F., BARRACLOUGH, T., ROSINDELL, J., BELLOT, S., COWAN, S., GOLOS, M., JEBB, M. & CHEEK, M. 2020. A phylogenomic analysis of Nepenthes (Nepenthaceae). Molecular Phylogenetics and Evolution 144: article 106668. VICTORIANO, M. 2021. A new species of Nepenthes (Nepenthaceae) and its natural hybrids from Aceh, Sumatra, Indonesia. Reinwardtia 20(1): 17–26. WISTUBA, A., NERZ, J. & FLEISCHMANN, A. 2007. Nepenthes flava, a new species of Nepenthaceae from northern part of Sumatra. Blumea 52: 159–162. REINWARDTIA 24 [VOL.21