Research Article |
Corresponding author: Mat Yunoh Siti-Munirah ( sitimunirahfrim1@gmail.com ) Academic editor: Michal Hroneš
© 2024 Mat Yunoh Siti-Munirah, Chin Hardy-Adrian, Sharipudin Mohamad-Shafiq, Zainuddin Irwan-Syah, Abd Halim Hamidi.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Siti-Munirah MY, Hardy-Adrian C, Mohamad-Shafiq S, Irwan-Syah Z, Hamidi AH (2024) Thismia malayana (Thismiaceae), a new mycoheterotrophic species from Peninsular Malaysia. PhytoKeys 242: 229-239. https://doi.org/10.3897/phytokeys.242.120967
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A new species of the mycoheterotrophic genus Thismia from Malaysia is described and illustrated. Thismia malayana introduced here was found in two localities: in the lowlands of Gunung Angsi Forest Reserve, Negeri Sembilan, and in the hilly dipterocarp forests of Gunung Benom in Tengku Hassanal Wildlife Reserve, Pahang. Thismia malayana falls into the section Thismia subsect. Odoardoa, as it has creeping vermiform roots and free equal tepals. It is characterised by the following taxonomically important features: a sepia-brown, urceolate-curved floral tube, free equal tepals with terminal appendages, prominent bright yellow annulus and bright violet-blue stamens each bearing five appendages (one pair of club-shaped inwards-pointing, one pair of acute outwards-pointing, and one central appendage). According to the categories and criteria of the IUCN Red List, T. malayana is provisionally classified as Vulnerable.
Negeri Sembilan, new species, Pahang, Thismia subsect. Odoardoa, vulnerable
The tropical rainforests of Southeast Asia together form the second largest area of tropical rainforests in the world. Also, the tropical lowland evergreen rainforest is the most species-rich forest formation in the region and structurally the most complex one, with species composition varying according to local soil and drainage conditions (
One of the most remarkable characteristics of Thismia is its mycoheterotrophic way of life. Unlike most plants, its species do not produce chlorophyll and are not capable of photosynthesis. A mycoheterotrophic plant is in fact a parasite of the mycorrhizal symbiosis, cheating it of the carbon resources that are shared in the mycorrhizal symbiosis, and this adaptation allows it to survive in the undergrowth of forests where the light availability is low (
Another Thismia species is described here that is new to science. It was first discovered in 2020 in the Tengku Hassanal Wildlife Reserve (WR) (formerly known as Krau Wildlife Reserve) in the state of Pahang in Malaysia. It was later found also in a forested area in Ulu Bendul Recreation Park (RP), a popular nature and recreation area in Negeri Sembilan, Malaysia. It is located near the town of Kuala Pilah, about 25 kilometres from Seremban. The Ulu Bendul RP is also part of the Gunung Angsi Forest Reserve (FR) and offers nature lovers, hikers and explorers the opportunity to immerse themselves in the beauty of the tropical rainforest and discover its rich flora and fauna as well as its contribution to wildlife conservation. The type material of the new species was collected in February 2023 at the edge of the Gunung Angsi main trail in the forest area of Ulu Bendul RP.
The specimens of the new species were collected from both localities (Map
Thismia malayana resembles T. chrysops but differs by the brown-whitish colour of the floral tube (vs. very dark sepia brown), glabrous surface of the tepal appendages (vs. finely ciliate), presence of transverse bars at inner surface of floral tube (vs. bars absent), supraconnective apex of each stamen with 5 appendages: one pair of club-shaped inwards-pointing, one pair of acute outwards-pointing, and one central appendage (vs. 7 appendages: one pair of club-shaped, one pair of acute and 3 central appendages).
Thismia malayana A flowering plant B flower, side view C flower, view from above D flower, longitudinal section E three stamens, outer view F tepal with terminal appendage, adaxial view G ovary, longitudinal section H style and stigma I involucral bract, adaxial view J leaf, adaxial view. All drawn by Mohamad Aidil Noordin from spirit material, Siti-Munirah FRI 101705 (A–C); FRI 101701 (D–J).
Malaysia. Peninsular Malaysia: Negeri Sembilan, Kuala Pilah Distr., Gunung Angsi FR, Ulu Bendul RP, a trail to Gunung Angsi., elevation ca. 206–208 m a.s.l., 9 February 2023. Siti-Munirah FRI 101705 (holotype KEP!, spirit collection, barcode no. SC12021]).
Thismia malayana A flowering plant A1 floral tube, inner surface A2 annulus and stamen filaments, view from inside B inflorescence with anthetic flower and several young fruits B1 style and stigma B2 annulus, top view C flower, side view D, E stamens, view from inside and from outside, E1 stamen supraconnectives: one pair of club-shaped inwards-pointing, one pair of acute outwards-pointing, and one central appendage F stamen supraconnectives, apical view G stamen tube, view from below H, H1 fruit after dehiscence, top view, H2 seeds I shoot base with roots. Photos by Siti-Munirah (A1–I) and Hardy-Adrian (A) from FRI 101701 (A), FRI 101702 (F, G, I), FRI 101703 (E1), FRI 101705 (B, B2, H, H1, H2) & FRI 101710 (A1, A2, B1, C, D, E). Images not to scale (see dimensions in description and Figs
Achlorophyllous herb, up to 10 cm tall, predominantly glabrous. Roots vermiform, unbranched, ca. 1 mm in diameter, light brown. Stem erect, up to ca. 6 cm long, 0.2 cm in diameter, pale brownish, bearing 1–4 flowers. Leaves 2–4, alternate, distant, triangular to narrowly triangular, scale-like, apex acute, margin slightly irregularly serrate (almost entire), 6 mm long, ca. 1 mm wide at base, pale brown. Involucral bracts 3, spirally/alternately arranged, similar to leaves but slightly larger, triangular to narrowly triangular, scale-like, apex acute, margin entire, 8 mm long, ca. 1.5–2.5 mm wide at base, pale brown or pale orange. Pedicel ca. 2 mm long at anthesis, elongating to ca. 5 cm long after anthesis, pale brown. Flowers terminal, asymmetrical, slightly zygomorphic, ca. 13 mm long (including ovary). Floral tube urceolate-curved, ca. 7 mm long, ca. 5 mm wide at middle, ca. 4 mm wide at base, sigmoidally bent in lower part; outer surface brown to whitish-sepia (whitish proximally & brown distally), with 12 longitudinal ribs orangish proximally & dark brown distally; inner surface reticulate, with whitish transverse bars, of similar color as outer surface. Tepals 6, free, triangular to ovate, apex acute, up to ca. 2.5 mm long, ca. 1.5–2.6 mm wide at base, dark brown, apically bearing a tentacle-like appendage; appendage narrowing towards apex, each equal in length up to ca. 6 mm long, 0.5 mm wide, whitish towards apex, becoming brownish with age. Annulus moderately raised, ring-shaped, ca. 5.4 mm in diameter, with ring width ca. 1.2 mm, orange, becoming bright yellow with age, aperture ca. 3.2 mm in diameter. Stamens 6, pendent from annulus; filaments free, ca. 1 mm long, curved downwards, yellowish to whitish; anther ca. 0.7 mm long; connectives and supraconnectives narrow at base (ca. 1.5 mm wide) and broad at apex (ca. 2 mm wide), with outer side bluish to violet; inner side bluish, violet, whitish to yellowish, flattened at inner surface, laterally connate to form a tube, ca. 4.5 mm long, supraconnective apex with one pair of club-shaped inwards-pointing, ca. 0.8–1 mm long and one pair of acute outwards-pointing ca. 0.3 mm long appendages, and one central appendage ca. 0.5–0.6 mm long; supraconnective bearing a skirt-like lateral appendage at outer side protruding towards inner side of floral tube, bearing trichomes at both sides; lateral appendage not exceeding the tip of the supraconnective appendages, margin lobed with translucent trichomes; interstaminal glands inserted on the line of fusion between supraconnectives at the level of attachment of lateral appendages, bluish (concolorous with supraconnectives). Ovary inferior, unilocular; placentas 3, free, column-like, arising from the bottom of the ovary; ovules numerous. Style ca. 0.74 mm long, dark blackish; stigma ca. 0.85 mm long, papillose, 3-lobed, with lobes ± rectangular and bifurcate at apex, dark blackish. Fruit dehiscent, cup-shaped, 6 mm in height, 6–8 mm in diameter, pale white to creamy. Seeds long oval, ca. 0.38–0.41 mm long, ca. 0.15–0.17 mm wide.
Malaysia. Peninsular Malaysia: Negeri Sembilan, Kuala Pilah District, Gunung Angsi FR, Ulu Bendul RP, elev. ca. 206–208 m, February 2023, Siti-Munirah, FRI 101701 (KEP), FRI 101702 (KEP), FRI 101703 (KEP), FRI 101704 (KEP) FRI 101709 (KEP), FRI 101710 (KEP), FRI 101711 (KEP); Pahang, Temerloh District, Tengku Hassanal WR, elev. ca. 200 m, 31 December 2020, Mohamad-Shafiq & Irwan-Syah, FRI 91126 (KEP).
Endemic to Peninsular Malaysia. Recorded in two localities: one in Gunung Angsi FR in Negeri Sembilan state and another in Tengku Hassanal WR in Pahang state (Fig.
Habitat (in situ) of Thismia malayana in Ulu Bendul RP in Gunung Angsi FR (A, B) and the Tengku Hassanal WR (C–E) A Thismia malayana at its habitat, which is located right next to the main trail to Gunung Angsi B Siti-Munirah showing the habitat of T. malayana C path to Lata Bujang and Gunung Benom D the plants growing on rotten wood E Mohamad-Shafiq observed a Thismia malayana in its habitat. Photos by Siti-Munirah (A, B) and Mohamad-Shafiq (C–E).
In medium-moist or mesic, shady areas of lowland dipterocarp forests at elevations of 200–450 m a.s.l. Flowering and fruiting usually from December to February but flowering also observed in June. According to the third and fourth author’s observations, T. malayana was only sighted and observed a few times a year, especially during the rainy season.
The specific epithet malayana is derived from Malaya, a name formerly used for Peninsular Malaysia. The epithet refers to the known region of the species distribution.
According to the IUCN standards (IUCN 2022), we propose to classify the preliminary conservation status of Thismia malayana as VU (Vulnerable). This particular species has only been found in two locations. One of the sites is located in a protected area (Tengku Hassanal WR), the other in a water catchment forest under the PRF class protection forest (Gunung Angsi FR), which also includes Ulu Bendul RP. Both habitats are therefore considered stable. However, the population of this species was detected near a hiking trail at both sites, which exposes this species to the risk of trampling due to its small size. During the survey conducted between 2022 and 2023, only less than 10 individuals were found. However, due to the limited time and area of the survey and also mycoheterotrophic nature of the species which remains hidden in the soil for most of its life, it was not possible to determine the estimated number of mature individuals in the population. Therefore, this species is classified as Vulnerable based on criterion D2.
According to the classifications of
Morphological comparison of T. malayana with T. chrysops (
Characteristics | T. malayana | T. chrysops | T. cornuta | T. inconspicua | T. kinabaluensis |
---|---|---|---|---|---|
Floral tube | |||||
Outer | |||||
colour | brown to whitish-sepia | very dark sepia brown | translucent-white | (light) brownish | brown or beige |
colour of longitudinal ribs | |||||
upper part | dark brown in | rose pink | pale pinkish | sepia-brown | light brown or beige streaks |
lower part | orangish | chocolate-brown | pale pinkish | both ribs and background gradually darkening toward the apex | of the same colour as the floral tube |
Inner | |||||
transverse bars | present | absent | absent | absent | present |
Annulus | |||||
colour | bright yellow | bright yellow | pinkish | sepia-brown on the outer margin, brownish-orange to light orange on the inner margin and grayish in between | with blue circle on the outer margin, orange to yellow on the inner margin |
Tepal | |||||
colour | dark brown | bright sienna, brown/ chocolate brown | white | sepia-brown | pale blue |
Appendages | |||||
colour | brown to whitish | bright sienna brown | white | sepia-brown | pale blue |
surface | glabrous | finely ciliate | glabrous | glabrous | glabrous |
Stamens | |||||
colour | bluish, violet, whitish, yellowish | unknown | translucent-white | translucent-white | translucent-white |
appendages of supraconnectives | 5 (2 club-shaped pointing centripetally, 2 acute pointing centrifugally and 1 central appendage) | several, (2 club-shaped and few shorter ones) | 2 club-shaped | 4 (2 club and 2 tooth-shaped) | 3 (1 filiform between 2 club-shaped) |
We thank the Jabatan Perhutanan Negeri Sembilan (JPNNS) and Jabatan Perhutanan Semenanjung Malaysia (JPSM) for permission to conduct a botanical collection, Jabatan Perlindungan Hidupan Liar dan Taman Negara (PERHILITAN) and Persatuan Pemandu Pelancong Mukim Ulu Cheka (PAMUC) for deposited specimen from Tengku Hassanal WR to Kepong Herbarium (KEP). We would like to thank the staff of Ulu Bendul RP for their assistance and Angan Atan for his help during the fieldwork. We would like to thank all reviewers, Michal Hroneš, Michal Sochor, Martin Dančák and Maxim Nuraliev for constructive comments on our manuscript. We thank Mohamad Aidil Noordin for the botanical drawings, Wendy SY Yong for the assistance in conservation status assessment and Mohd Faizal MT for the encouragement and great help in many ways to the first author in the preparation of the manuscript.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was conducted under the Flora of Peninsular Malaysia Project (FPM) at the Forest Research Institute Malaysia (FRIM), Kepong, funded by the Ministry of Natural Resources and Environmental Sustainability (NRES), under the 12th Malaysian Plan (SPPII No. P23085100018003). Special thanks to the Nagao Research Grant (NEF) for partially funding the Thismia research.
All authors contributed equally to this study and made a significant contribution to the overall result.
Mat Yunoh Siti-Munirah https://orcid.org/0000-0002-5062-9988
All of the data that support the findings of this study are available in the main text.