Monday, June 24, 2019

[Botany • 2019] Thismia submucronata (Thismiaceae) พิศวงตาปีศาจ • A New Species from Mainland Southeast Asia


Thismia submucronata Chantanaorr., Tetsana & Tripetch

in Chantanaorrapint, Tetsana, Tripetch & Suddee, 2019.
พิศวงตาปีศาจ ||  DOI: 10.6165/tai.2019.64.240

Abstract
Thismia submucronata is described and illustrated as a new species from Thailand. The new species is characterized by 1) vermiform roots, 2) inner perianth lobes forming a convex mitre with a mucro together with three foveae at apex, 3) the inner surface of perianth tube possessing an irregularly reticulate surface without transverse bars, 4) the presence of papillate hairs at the annulus surface and the outer surface of stamen filaments, and 5) the stamens positioned almost at apex of annulus. Morphological description, illustrations of the new species and a comparison with the related species are presented.

Keyword: Mycoheterotrophy, New species, Thailand, Thismia submucronata, Thismiaceae

  

Thismia submucronata (A–H): A: Plants with underground parts. B: Plants in natural habitat. C−D: Top view of mitre. E: Side view of flowers. F−G: Longitudinal section of flowers. H: Young fruit, showing ovary and stigma. 

Fig. 2. Thismia submucronata (A–H): A: Plants with underground parts. B: Plants in natural habitat. C−D: Top view of mitre. E: Side view of flowers. F−G: Longitudinal section of flowers. H: Young fruit, showing ovary and stigma.
T. angustimitra (I−J): I: Flowers. J: Longitudinal section of flower.
T. mirabilis (K–L): K: Top view of mitre. L: Longitudinal section of flower.
T. nigricans (M): M. longitudinal section of flower.
Photos A–E & H–M by S. Chantanaorrapint; 
F–G by P. Tripetch. 



Thismia submucronata Chantanaorr., Tetsana & Tripetch, sp. nov.

Diagnosis: Thismia submucronata is similar to T. mucronata, but differs in having three foveae together with a mucro at the apex of the mitre and outer surface of stamen filaments and both surfaces of annulus covered by papillate hairs.
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Fig. 1. Thismia submucronata: A & B.: Plants with flowers. C & D: Side view of flowers. E: Outer tepal. F: Longitudinal section of perianth tube with stamens. G: Inner view of three pendulous stamens. H. Stigma and style. I. Young fruit. A & C–I from the holotype Chantanaorrapint & Suwanmala 2732, B from Tetsana et al. 311 (BKF). All drawn by S. Chantanaorrapint.

Etymology: The specific epithet “submucronata” refers to the presence of a short mucro at the top of the mitre

Habitat, ecology and distribution: Thismia submucronata is known only from two localities: Phu Hin Rong Kla [Phitsanulok province] and Phu Suan Sai National Parks [Loei province]; however, it may also occur in other areas of Northern and Northeastern Thailand with similar climatic conditions and vegetation type. The new species grows amongst leaf litter, under shade of moist evergreen forest, near waterfall or streamside, at elevation of 1200−1300 m. Flowering and fruiting was observed from May to July.

 


Sahut Chantanaorrapint, Naiyana Tetsana, Petch Tripetch and Somran Suddee. 2019. Thismia submucronata (Thismiaceae), A New Species from Mainland Southeast Asia. Taiwania. 64(3); 240-244. DOI: 10.6165/tai.2019.64.240