Friday, July 28, 2017

[Botany • 2017] Thismia brunneomitroides • A New Mycoheterotrophic Species (Thismiaceae) from southern Thailand


Thismia brunneomitroides  Suetsugu & Tsukaya

พิศวงกรุงชิง  DOI: 10.11646/phytotaxa.314.1.9 

Abstract

Here we describe a new species of the mycoheterotrophic genus Thismia (Thismiaceae), Thismia brunneomitroides, discovered during a botanical survey in Khao Luang National Park, Peninsular Thailand. Thismia brunneomitroides resembles Thismia brunneomitra from Brunei Darussalam in that both species possess inner tepal lobes that are connate to form a mitre with three projections at the apex and large lateral appendage of the connective. However, it differs in having ivory flowers with twelve pale orange to brownish orange vertical stripes on the perianth tube and slightly dentate lateral appendage of the connective which does not exceed apical part of the connective. Descriptions, illustrations and a key to the 13 species of Thismia in the Thai-Malay Peninsula are provided.

Keywords: mycoheterotrophy, taxonomy, Sarcosiphon, Monocots


FIGURE 1. Thismia brunneomitroides from the type locality. A. Flowering plant. 

Thismia brunneomitroides Suetsugu & Tsukaya, sp. nov.

 Type:—THAILAND, Nakhon Si Thammarat Province, Khao Luang National Park, along trail to Kung Ching Waterfall, in lowland evergreen forest,  elev. 285 m, 15 December 2015, Tagane S., Toyama H., Nagamasu H., Rueangruea S., Hemrat, C., Keiwbang W. T4968 (holotype BKF!–a spirit collection, isotype TNS!–a spirit collection).

Diagnostic characters:—Thismia brunneomitroides is most similar to Thismia brunneomitra Hroneš, Kobrlová & Dančák (2015: 173) from Brunei Darussalam in having inner tepal lobes connate to form a mitre with three projections at the apex and large lateral appendage of the connective. However, it differs from T. brunneomitra in having ivory flowers with twelve pale orange to brownish orange vertical stripes on the perianth tube (vs. brown to blackish flowers with twelve darker vertical stripes on the perianth tube) and slightly dentate lateral appendage of the connective which does not exceed apical part of the connective (vs. entire lateral appendage of the connective which exceeds whole apical part of the connective). 

Etymology:—The new species is named after the great morphological similarity to T. brunneomitra.

Habitat and Ecology:—Less than 10 individuals were found in shaded understory of lowland evergreen forest. No other mycoheterotrophic species were found in the locations in which the new Thismia were collected.


. Kenji Suetsugu, Hirokazu Tsukaya, Shuichiro Tagane, Somran Suddee, Sukid Rueangruea and Tetsukazu Yahara. 2017. Thismia brunneomitroides (Thismiaceae), A New Mycoheterotrophic Species from southern Thailand.
 Phytotaxa. 314(1); 103–109.  DOI: 10.11646/phytotaxa.314.1.9