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| Thismia sitimeriamiae Siti-Munirah, Dome & Thorogood in Siti-Munirah, Dome & Thorogood, 2021. |
Abstract
We describe an extraordinary new species in the genus Thismia from the Terengganu State of Malaysia in the Malay Peninsula. The new species, which we name Thismia sitimeriamiae, is distinct from all other Thismia species known to science, most notably in its unique mitre configuration formed by the inner tepals and its floral surface morphology characterised by conspicuous orange trichomes. We discuss our findings in the context of underestimated species diversity in the genus Thismia and implications for their conservation. We recommend assigning T. sitimeriamiae the conservation status as Critically Endangered (CR) according to IUCN criteria.
Keywords: conservation, forestry, mycoheterotrophy, species diversity, taxonomy
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| Figure 2. Illustration of Thismia sitimeriamiae Siti-Munirah, Dome & Thorogood A cross section of perianth showing pendulous stamens (above) and slender pistil (beneath) B pistil C aerial view of flower showing mitre and portions of apical part of floral tube and outer tepals D fruit E stamen (showing outer side of connective) F flower, lateral view G habit, showing inflorescence (flower) and roots. All illustrated from FRI 91118 (excluding D, in situ). |
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| Figure 1. Thismia sitimeriamiae Siti-Munirah, Dome & Thorogood A the habitat in Gunung Sarut, in the State of Terengganu (PM) B the habit of flowering specimen C a fruiting specimen (in situ). |
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| Figure 3. Thismia sitimeriamiae Siti-Munirah, Dome & Thorogood A habit with roots B flower, view from below C aerial view of floral tube (mitre removed) D flower, aerial view E mitre, lateral view F ovary and pistil, lateral view G flower, lateral view H mitre, lateral view I stellate trichomes on the outer surface of floral tube. All from FRI 91118 (A–F) and a plant photographed in situ (G–I). Images not to scale (see dimensions in description and Figure 2). |
Thismia sitimeriamiae Siti-Munirah, Dome & Thorogood, sp. nov.
Diagnosis: Thismia sitimeriamiae has a unique combination of morphological traits, by which it differs from all its congeners including its orange colour, its surface characteristics and its floral architecture: the flower is strigose with pale orange simple and stellate trichomes covering the outer surface of the floral tube, mitre and ovary; the upper surface of the annulus is covered by very short trichomes; the outer tepals are reduced and inconspicuous and the inner tepals are curved upwards, connate, forming an umbrella/parasol-like mitre with a flattish apex.
Distribution: Endemic to Terengganu, Peninsular Malaysia. Currently known only from the type locality (Map 1).
Ecology: Lowland dipterocarp forest on moist soil in shade at an elevation of 209 m a.s.l. Flowering and fruiting from December to February.
Etymology: Thismia sitimeriamiae is dedicated to Siti Meriam, the mother of the second author (Dome Nikong), in honour of her unparalleled support for the conservation activities pursued by Dome Nikong and her help in maintaining his plant collections.
Mat Yunoh Siti-Munirah, Nikong Dome and Chris J. Thorogood. 2021. Thismia sitimeriamiae (Thismiaceae), An Extraordinary New Species from Terengganu, Peninsular Malaysia. PhytoKeys. 179: 75-89. DOI: 10.3897/phytokeys.179.68300
