Taiwania 67(4): 587‒590, 2022 DOI: 10.6165/tai.2022.67.587 587 Thottea beungongtanoeh (Aristolochiaceae), a new species from Aceh, northern Sumatra Wendy A. MUSTAQIM * , Zulfan ARICO Program Studi Biologi, Fakultas Teknik, Universitas Samudra, Jl. Prof. Dr. Syarief Thayeb, Meurandeh, Langsa Lama, Langsa, Aceh 24416, Indonesia. * Corresponding author’s email: wendyachmmadm@gmail.com (Manuscript received 21 July 2022; Accepted 31 October 2022; Online published 9 November 2022) ABSTRACT: A species new to science, Thottea beungongtanoeh Mustaqim (Aristolochiaceae), is described based on a specimen collected from a lowland mixed dipterocarp forest in the eastern part of Aceh Province, the northernmost province in Sumatra. This species differs from all previously described species in having 33-lobed style, the highest count for the genus. Morphological description, distribution, phenology, comparison with the similar species, and the photographs of the living plants are provided. KEY WORDS: Acehnese Language, cauliflory Indonesia, the lowland mixed dipterocarp forest, Thottea grandiflora, West Malesia. INTRODUCTION Thottea Rottb. (1783) (Aristolochiaceae) is an Indo- Malayan genus with 45 species known to science (Hou, 1984; Yao, 2013; Mustaqim and Putra, 2020; Le et al., 2021; POWO, 2022). One of its centres of distribution is in Sumatra represented by 10 species (Hou, 1984; Mustaqim and Putra, 2020). On this island, the taxonomic study of the genus is not yet complete. A few species are poorly known due to its limited number of specimens like T. beccarii Ding Hou (1981) and T. tapanuliensis Mustaqim (Mustaqim and Putra, 2020) or described based on incomplete materials like T. straatmanii Ding Hou (1984). During recent botanical surveys in the lowland mixed dipterocarp forests in eastern Aceh Province in 2022, one specimen of Thottea was collected from the forest floor of undulating terrain. It is unique among Thottea in having the 33-lobed style. Literature reviews (Hou, 1981, 1984; Phuphathanaphong, 1985; Kumar et al., 2000; Huang et al., 2003; Murugan, 2011; Yao, 2013, 2015; Sunil and Kumar, 2014; Mustaqim and Putra, 2020; Le et al., 2021) and examination of the types of other species as well as other specimens in various herbaria either directly or as images from ANDA, BO, FIPIA, and L (abbreviation follow Thiers, 2022), we concluded that the specimen belongs to a species new to science, and here we described it below. This finding increases the number of Thottea in Sumatra to 11. MATERIAL AND METHODS The plant specimen examined in this study was collected during fieldwork trips in June 2022. The flowering materials were preserved in spirit while the other parts were dried for herbarium specimens. The description was prepared using the plant glossaries in Beentje (2016) and Hou (1984). An assessment of conservation status was performed using IUCN (2012) and IUCN Standards and Petitions Subcommittee (2022). Distribution map was created with SimpleMappr (Shorthouse, 2010). TAXONOMIC TREATMENT Thottea beungongtanoeh Mustaqim, sp. nov. Fig. 1. Type: INDONESIA. Aceh Province, Aceh Timur Regency, Bireum Bayeun Subdistrict, Alue Nyamuk Village, 4°31'18.9"N 97°51'07.5"E, 80 m asl, 22 June 2022, Mustaqim & Arico RSG8 (Holotype: ANDA). Diagnosis: Thottea beungongtanoeh can be recognized from other species in the genus by the 33- lobed style. It is similar to T. grandiflora Rottb., besides having more numerous style lobes (33 vs 20), this species differs in having inflorescence close to ground level (vs not from the ground level) and tubular perianth tube (vs campanulate). Perennial subshrubs, to c. 1.5 m tall. Stem ascending to erect, with horizontal apex, scarcely branched, terete, pubescent; node swollen, constricted above nodes. Leaves alternate, distichous; lamina chartaceous; obovate, the lower 1–2 usually elliptic or narrowly elliptic and distinctly smaller, 15.2–21.5 × 6.3–10.6 cm, base cuneate, apex shortly acuminate, margin entire, adaxially green, scabrous, abaxially pale green, patent-pubescent, midvein slightly prominent adaxially, distinctly raised abaxially, lateral veins 7–9 on each side of the midrib; petioles 4–6 mm long, densely covered with patent hairs. Inflorescences 1–2 arising from near the base of the stem, close or at the same with ground level, solitary to 3- flowered; peduncle c. 2 cm long, patent-pubescent, rachis c. 1.5 cm long, patently pubescent; bracts beef red, elliptic, 5–7 × 3–3.5 mm, apex obtuse, adaxially patently pubescent, abaxially glabrous, persistent after anthesis. Pedicels and ovary c. 1.7 cm long, longitudinally ribbed, patently pubescent. Perianth burgundy, tube ellipsoid,