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| Thismia domei Siti-Munirah, T. terengganuensis Siti-Munirah
& Thismia javanica J.J.Sm
in Siti Munirah & Nikong, 2019.
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Abstract
Two new species of the mycoheterotrophic genus Thismia Griff. (Thismiaceae), Thismia domei Siti-Munirah and T. terengganuensis Siti-Munirah from Peninsular Malaysia, are described and illustrated. Thismia domei, characterized by its perianth lobes that are upright and curve inward, but are imperfectly connate, falls within section Odoardoa. Thismia terengganuensis is characterized by its mitre with three appendages on its apex, so falls within section Geomitra. Both new species are unique and totally different from other described species, T. domei by the trichomes on its outer perianth tube surface and T. terengganuensis by its mitre with slender appendages. Thismia javanica J.J.Sm, also from Terengganu, is a new record for Peninsular Malaysia.
Keywords: Thismia, taxonomy, mycoheterotrophy, new species, Telemong Forest Reserve, Terengganu, Peninsular Malaysia
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| Figure 2. Thismia domei Siti-Munirah A, B habit of two plants C leaf D bract E perianth lobes from top F top view of apical part of perianth tube with annulus G inner adaxial view of six pendulous stamens H stamen attached to perianth tube I a perianth lobe with perianth tube from side view J ovary with stigma and placenta (below). All from Dome Nikong FRI 91111. Drawn by M. Aidil. The drawing is based on spirit material. |
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| Figure 1. Thismia domei Siti-Munirah A habit (A1 roots A2 tip of filiform appendages), B top view of plant C perianth tube covered with trichomes (C1 trichome C2 white spots D top view of flower showing perianth lobes overlapping and appendages on the each lobes forming loose mitre E top perianth tube covered with apical part of flower tube and annulus F longitudinal section of flower (F1 base perianth tube and ovary) G perianth lobes from outside H perianth lobes from inside I pendulous stamen attached to the inner wall of perianth tube (abaxial view of stamens) J pendulous stamen attached to the inner wall of perianth tube (adaxial view of stamens) (J1 stamen from side view J2 three appendages at apical margin) K ovary showing stigma (K1 ovary). Photo credit: A, A1, B, C, C1, D, F, G, H, J, J1, J2, K Dome Nikong; A2, C2, E, F1, I, K1 Siti-Munirah MY. |
Thismia domei M.Y.Siti-Munirah, sp. nov.
Diagnosis: The whole plant is completely white translucent and the flower is strigose with white trichomes covering the outer surface of the perianth tube and ovary; the apex of the perianth tube is partially covered by the apical part of flower tube with a ring-like annulus and together with six perianth lobes are upright and curve inwards with a dorsal long appendage on each lobe.
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Distribution: Endemic in Peninsular Malaysia, Terengganu. Currently known only from the type collection.
Ecology: In lowland dipterocarp forest on wet, moist soil in shade at an altitude of 207 m. Flowering in November-December. This new species was encountered on bamboo leaf litter near an elephant trail. When mature T. domei produces an unpleasant smell like rotting fish.
Etymology: The species is named after Mr Dome Nikong, professional photographer and freelance researcher, who first discovered this species and the other new species described below as well as T. javanica.
Notes: Thismia domei, based on colour, is most like T. clavarioides K.Thiele (Thiele and Jordan 2002) and Thismia taiwanensis S.-Z. Yang, R. M. K. Saunders & C.-J. Hsu, (Yang et al. 2002). Both have completely white perianth lobes that are upright and curved inwards towards the perianth tube with an appendage on each lobe. However, T. domei differs from these species in that its perianth tube is fully covered with thick trichomes and it has six perianth lobes each with an appendage as opposed to being completely glabrous and T. taiwanensis from Taiwan has only three perianth lobes with appendages and the perianth of T. clavarioides forms a mitre from Australia. T. domei is unusual in its conspicuous cell inclusion white spot which appear to be aleurone grains.
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| Figure 3. Thismia domei. A, B habitat on leaf litter within a bamboo clump (plant indicated by red arrow) C habit of the flowering T. domei D Mr Dome Nikong showing T. domei at different stages of anthesis E habit of T. domei. Photo credit: Dome Nikong. |
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| Figure 4. Thismia terengganuensis Siti-Munirah A habit of flowering and fruiting plants B top view of plant C root and stems D perianth tube E perianth lobes (inner forming a mitre, outer curved) F ovary with pistil (stigma) G fruits with seeds H stamens attached to the inner wall of mouth of the perianth tube (adaxial view) I stamens deflexed (abaxial view). Photo credit: A–D, G Dome Nikong; E, F, H, I Siti-Munirah MY. |
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| Figure 5. Thismia terengganuensis Siti-Munirah A flower and fruit B habit of fruiting plant C leaf D bracts E stamens (adaxial view) F stamens (abaxial view) G ovary showing free central placentation H stigma. All from Dome Nikong FRI 91112. Drawn by M. Aidil. |
Thismia terengganuensis M.Y.Siti-Munirah, sp. nov.
Diagnosis: Thismia terengganuensis is unique in its perfect mitre with the long filiform appendages not seen in any other species of Thismia. It has a racemose sessile inflorescence with large bracts. Its flower parts are brownish with brown striae with inner perianth lobes forming a dark brown mitre with a white slender appendage attached at apex. The outer perianth lobes at interval appear like a wing. It has creeping vermiform brown roots.
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Distribution: Endemic in Peninsular Malaysia, Terengganu. Currently only known from the type locality.
Ecology: In lowland dipterocarp forest on wet, moist soil in shade at altitude 227 m. Flowering in November-December on forest floor under canopy of dense shrubs.
Etymology: The epithet refers to the state, Terengganu, where it was found.
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| Figure 6. Thismia terengganuensis A habitat B habit of a fading T. terengganuensis plant. Photo credit: Dome Nikong. |
Notes: Thismia terengganuensis is most similar to species in sect. Sarcosiphon and sect. Geomitra in the shape of the perianth tube and mitre but differs in all other morphological parts, e.g. in its slender filiform appendages on the apex of mitre and also its connectives that are blunt without any apical appendages.
New record:
Thismia javanica J.J. Sm., Ann. Jard. Bot. Btzg. 23: 32. 1910
Jonker, Fl. Malesiana 1,4: 23. 1948;
Larsen, Fl. Thailand 5,1: 125. 1987.
Specimen: Dome Nikong FRI 91114 (KEP!)
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| Figure 7. Thismia javanica from Terengganu A habit B flower C opened to show the inside of the perianth tube. Photo credit: Dome Nikong. |
Distribution: Indonesia, Malaysia and Thailand.
Notes: The specimens of Thismia javanica were found not far from the T. terengganuensis population. We believe that T. javanica has a wider distribution in Peninsular Malaysia based on photographs of a specimen from Langkawi, Kedah, by late Abd Ghani Hussain. Unfortunately, there are no specimen to verify this.
Mat Yunoh Siti Munirah and Dome Nikong. 2019. Thismia domei and T. terengganuensis (Thismiaceae), Two New Species, and T. javanica, A New Record from Terengganu, Peninsular Malaysia. PhytoKeys. 124: 123-137. DOI: 10.3897/phytokeys.124.34728
