 |
| Thismia ornata Dančák, Hroneš & Sochor
in Dančák, Hroneš & Sochor, 2020.
DOI: 10.3372/wi.50.50106
|
Abstract
Thismia ornata and T. coronata (Thismiaceae), two new species from Sarawak (Malaysian Borneo) are described and illustrated. Thismia ornata belongs to T. sect. Thismia subsect. Odoardoa and occurs at several localities in western Sarawak around the city of Kuching. This species has been misidentified as T. aseroe until now, although the two species differ considerably. The species is assigned a preliminary conservation status of VU according to IUCN criteria. Thismia coronata belongs to T. sect. Sarcosiphon and has been found at only one site near the village of Long Tuyo in Lawas district of northern Sarawak. It is related to T. goodii and T. kelabitiana. The species is assigned a preliminary conservation status of CR.
KEYWORDS: Borneo, Malesia, mycoheterotrophy, new species, Sarawak, Thismia, Thismia aseroe, Thismiaceae, Tropical rain forest
 |
| Fig. 1. Thismia ornata – A: habit of flowering plant; B: flower bud; C: detail of flower, apical view; D: stigma; E: inner view of stamens,; F: seed; G: outer view of stamens and inside of floral tube.
– From Sochor & al. BOR 51/19 (A, C–E, G), BOR54/19 (B), BOR 56/19 (F).
– Drawn by Kateřina Janošíková.
|
 |
| Fig. 3. Distribution of Thismia ornata (yellow circles) and T. coronata (red circle). |
 |
| Fig. 2. Thismia ornata – A, B: overall appearance; C: detail of flower, apical view; D: ovary, stigma and inner surface of floral tube (background grid spacing = 1 mm); E: seeds; F: inner view of stamens; G: lateral view of connective after cutting off neighbouring connective; H: outer view of stamen.
– From Sochor & al. BOR53/19 (A), BOR51/19 (B–D, F–H) and BOR56/19 (E).
|
Thismia ornata Dančák, Hroneš & Sochor, sp. nov.
Diagnosis — Thismia ornata differs from the most similar known species, T. filiformis Chantanaorr., by flower size (to c. 10 cm in diam. vs to c. 3 cm including tepal appendages), inner surface of floral tube (with very fine bright orange reticulum inside vs lacking any reticulum), length of tepal appendages (to 35 mm vs to 8 mm), appendages on apical margin of connective (five of three different shapes vs three of two different shapes) and shape of lateral appendage (with small horn-shaped projection arising from each side of the lateral appendage vs lacking any horn-shaped projections).
Distribution — Thismia ornata occurs in western Sarawak in a number of locations surrounding Kuching, including Kubah National Park, Santubong National Park, Dered Krian National Park and Fairy Cave Nature Reserve (Fig. 3).
Habitat — Thismia ornata inhabits a wide range of tropical lowland rain forest habitats with an altitudinal range from 40 m to c. 300 m a.s.l. It is known from rather dry limestone outcrops, lowland mixed dipterocarp forests, riverine forests including forests with some anthropogenic disturbance.
Conservation status — Thismia ornata is endemic to Borneo. Most, if not all, known populations occur within national parks and other protected areas. While the extent of occurrence (EOO) is c. 270 km2, its minimal area of occupancy (AOO) could be estimated to be 30 km2. It is known from several populations, which represent three locations (sensu IUCN 2012). Thismia ornata is therefore assigned a preliminary conservation status of VU (D1+2) according to the IUCN Red List categories and criteria (IUCN 2012).
Etymology — The specific epithet is the feminine form of the Latin adjective ornatus (ornate or decorated), which-reflects the colourful flowers and very fine bright orange reticulum inside the floral tube that resembles lace.
 |
| Fig. 5. Thismia coronata – A: lateral view of flower; B: apical view of flower; C: habit of flowering plant; D: stigma; E: outer view of stamens; F: inner view of stamens.
– From Sochor & al. BOR11/19 (A–H). – Drawn by Kateřina Janošíková.
|
 |
| Fig. 6. Thismia coronata – A: flower prior to anthesis; B, C, D: overall appearance; E: apical view of flower; F: stigma; G: roots; H: outer bottom view of stamen.
– Finest grid spacing in D and G = 1 mm.
– From Sochor & al. BOR11/19 (A–H).
|
Thismia coronata Hroneš, Dančák & Sochor, sp. nov.
Diagnosis — Thismia coronata differs from T. kelabitiana by the shape of outer tepals (entire with a single tooth in the middle vs deeply divided into several acute lobes), mitre apex (without tetrahedral depressions on upper surface vs with tetrahedral depressions on upper surface), smaller size of flower (1.8–2.3 cm vs 2.6–2.8 cm long) and flower colour (dark yellow to orange across whole flower vs white floral tube and bright yellow upper parts).
Distribution — Thismia coronata is known only from the type locality and its close surroundings in the Paya Maga mountain range in northern Sarawak (Fig. 3). At least 40 individuals were recorded at the locality.
Habitat — Thismia coronata occurs in lower montane primary tropical rainforest at an altitude around 1300 m a.s.l. It was found in relatively humid forest with dense understorey (Fig 7C). A variety of other mycoheterotrophic species were abundant at the type locality and surroundings, including Burmannia lutescens Becc. agg. (Burmanniaceae), Cystorchis aphylla Ridl. (Orchidaceae), Epirixanthes kinabaluensis T. Wendt, E. pallida T. Wendt (both Polygalaceae), Exacum tenue (Blume) Klack. (Gentianaceae), Lecanorchis multiflora J. J. Sm. (Orchidaceae), Sciaphila arfakiana Becc., Sciaphila sp. (both Triuridaceae) and Thismia viridistriata Sochor, Hroneš & Dančák. Herbaceous vegetation was otherwise sparse.
Conservation status — Thismia coronata is endemic to Borneo and the only known population occurs outside national parks and other protected areas. The number of mature individuals observed is fewer than 50. The extent of occurrence cannot be estimated because the species is known only from the type locality and its area of occupancy (AOO) is estimated to be only 4 km2. Thismia coronata is therefore assigned a preliminary status of CR (B2ab(iii); D) according to the IUCN Red List categories and criteria (IUCN 2012).
Etymology — The specific epithet is the feminine form of the Latin adjective coronatus (crowned), which reflects the shape and colour of the tepals resembling a royal crown.
Martin Dančák, Michal Hroneš and Michal Sochor. 2020. Thismia ornata and T. coronata (Thismiaceae), Two New Species from Sarawak, Borneo. Willdenowia. 50(1); 65–76. DOI: 10.3372/wi.50.50106
