Monday, October 15, 2018

[Botany • 2018] Thismia kelabitiana (Thismiaceae) • A New Unique Fairy Lantern from Borneo Potentially Threatened by Commercial Logging

Thismia kelabitiana Dančák, Hroneš & Sochor

in Dančák, Hroneš, Sochor & Sochorová, 2018.
Pa’Umor Fairy Lantern  ||  DOI:  10.1371/journal.pone.0203443 

Thismia kelabitiana, a new unique species from the Sarawak state of Malaysia in the island of Borneo is described and illustrated. This new species is not similar to any species of Thismia described so far especially by having a unique form of mitre and outer perianth lobes deeply divided into 8–10 acute lobes and forming striking fringe around perianth tube opening. The species appears to be critically endangered due to ongoing logging activities in the region. It may potentially become a surrogate species for lower montane forests of the region and thus help protect them against further destruction.

Fig 1. Thismia kelabitiana. A, Plant with flower bud. B, Plant with young flower. C, Plant with mature flower. D, Whole plant with root system. E, Detail of mitre and perianth opening. Photos Michal Sochor. 

Fig 3. Thismia kelabitiana. A, Habit of flowering plant. B, Side view of flower. C, Inner view of stamens. D, Style with stigma. E, Outer view of stamens. Drawn by Kateřina Janošíková.

Fig 2. Thismia kelabitiana. A, Outer view of stamens showing the lateral appendages and apical parts of connectives. B, Young capsule with persistent stigma. C, Inner view of stamens showing ribbed connectives. D, Seeds inside mature capsule. Photos Michal Sochor. 


Thismia kelabitiana Dančák, Hroneš & Sochor, sp. nov. 

Type. MALAYSIA, Sarawak: Kelabit Highlands, Pa'Umor village, Anak Kadi Ridge, 4.4 km SSE of the village. Elevation 1195 m a.s.l., 13 January 2017. M. Sochor, M. Hroneš, M. Dančák, Z. Egertová & J.R. Pasan BOR1/17 (holotype SAR [in spirit and herbarium specimen, accession number Sochor/BOR-1/17], isotype OL [35272]).

Diagnosis. Thismia kelabitiana differs significantly from all congeneric species by the combination of the following traits, e.g., flowers large (up to 2.8 × 1.8 cm), outer perianth lobes deeply divided into 8–10 acute lobes and forming striking fringe around perianth tube opening, mitre relatively small and flat elevated by three long filiform pillars, connectives with prominent longitudinal rib and three appendices on apical margin.

Fig 4. Habitat of Thismia kelabitiana. Ravine of a small stream in lower montane tropical rain forest. Photo Michal Sochor.

Habitat and ecology. The species occurs in lower montane primary tropical rainforest at an altitude around 1200 m a. s. l. It was found in humid stream ravines as well as in relatively drier open forest sites (Fig 4). A variety of other mycoheterotrophic species were abundant at the type locality, including Aphyllorchis pallida, Burmannia lutescens agg., B. championii, Cystorchis aphylla, Gymnosiphon aphyllus agg., Epirixanthes kinabaluensis, Exacum tenue, Platanthera saprophytica, Sciaphila arfakiana, S. cf. nana, S. tenella, Thismia cornuta, T. minutissima ined., T. aff. nigra and T. viridistriata. Herbaceous vegetation was otherwise sparse. Thismia kelabitiana seems not to prefer any particular environmental conditions at the locality as it occurs in various aspects of slopes with various inclinations either in rugged ravines or relatively flat terrain in various distances from a stream.

Distribution. The species is known only from the type locality and the other, 600 m distant locality, where plants have only been photographed. Both localities are found on a ridge south-east from Pa’Umor village in the Bario district of Sarawak (Malaysia).

Etymology. The specific epithet reflects the geographical origin of the species in the Kelabit Highlands, the land of the Kelabit people.

Common name. Pa’Umor Fairy Lantern. There is no widely accepted generic common name for the genus Thismia. The recent wave of interest as well as potential conservational employment, nevertheless, calls for this name. Sometimes the name Fairy Lantern is used [Thiele & Jordan, 2012, Lưu et al., 2014] which has originally belonged to Thismia rodwayi (either in singular or plural form as Fairy Lanterns). Since the name has already been used for a few other Thismia species, we follow this approach. We suggest calling Thismia kelabitiana Pa’Umor Fairy Lantern. The name is derived from Pa’Umor village community in whose forest the species occurs.

Martin Dančák, Michal Hroneš, Michal Sochor and Zuzana Sochorová. 2018. Thismia kelabitiana (Thismiaceae), A New Unique Fairy Lantern from Borneo Potentially Threatened by Commercial Logging.  PLoS ONE. 13(10): e0203443.  DOI:  10.1371/journal.pone.0203443