Thursday, February 6, 2020

[Botany • 2018] Thismia breviappendiculata (Thismiaceae) • A New Mycoheterotrophic Plant from Southern Myanmar


Thismia breviappendiculata Nob. Tanaka

in Tanaka, Aung & Latt. 2018.  
Bull. Natl. Mus. Nat. Sci., Ser. B. 44(2)

Abstract 
Thismia breviappendiculata Nob. Tanaka (Thismiaceae) is described and illustrated. The new species was discovered in the bamboo forest on the limestone foothill, the Tanintharyi Nature Reserve, peninsular Myanmar. Description, photographic data including habitat, illustration and a key to the species of the genus presently recorded from Myanmar are provided. The new species is easily distinguished from the similar species, T. javanica J. J. Sm. and T. tentaculata K. Larsen & Aver. by very short appendage with claviform apex, white perianth lobes without any colored ridges. 

Key words: Myanmar, mycoheterotrophic, new species, Thismia, Thismiaceae.

Fig. 1. Thismia breviappendiculata Nob. Tanaka. 
A, habitat. B, two individuals growing in shade on wet leaf litter in the lowland bamboo forest in Tanintharyi Nature Reserve. C, side view of inflorescence. D, top view of inflorescence.

 

Thismia breviappendiculata Nob. Tanaka, sp. nov.  

Diagnosis: Thismia breviappendiculata is similar to T. javanica J.J.Sm. and T. tentaculata K. Larsen & Aver. in having the inner perianth lobes of isosceles triangle form tapering filiform appendage, but easily distinguished from the latters by very short appendage with claviform apex, white perianth lobes without any colored ridges.

 Habitat: — Thismia breviappendiculata grows on wet leaf litter in the lowland bamboo forest or secondary seasonal lowland forest. The plant prefers humid places in shade. (Fig. 1-A). 

Distribution: — Myanmar. Two populations were found in the reserved forests, Tanintharyi in Myanmar and the specimens were collected from the both of the places (Tanaka et al. 156 and 173). The species is likely to be common around the type locality, and further extension of surveys in this region may discover more populations. Its distribution range may share with peninsular Thailand. 

Etymology: The specific epithet is derived from very short appendage of perianth lobes.

Note: Sect. Thismia is classified into two subsections, Odoardoa Schltr. with equal perianth lobes in length and size and Brunonithismia Jonker with larger inner perianth lobes than outer ones (Schlechter, 1921; Jonker, 1938). This new species may be assignable to sect. Thismia subsect. Brunonithismia Jonker.


Nobuyuki Tanaka, Mu Mu Aung and Myo Myin Latt. 2018.   Thismia breviappendiculata (Thismiaceae), A New Mycoheterotrophic Plant from Southern Myanmar. Bull. Natl. Mus. Nat. Sci., Ser. B. 44(2); 67-72.