Thismia bryndonii Tsukaya, Suetsugu & M.Suleiman, 2017

Tsukaya, Hirokazu, Suetsugu, Kenji & Suleiman, Monica, 2017, Thismia bryndonii (Thismiaceae), a new species from Maliau Basin, Sabah, Borneo, Phytotaxa 312 (1), pp. 135-138 : 135-137

Thismia bryndonii Tsukaya, Suetsugu & M.Suleiman , sp. nov. ( Fig. 1 ).

Type: — MALAYSIA. Sabah: Maliau Basin Conservation Area, along the Belian Trail , elev. ca. 260 m, 04°41’50”N, 116°54’27”E, 30 Sept 2016, Tsukaya, Suetsugu, & Suleiman TSS-14 (holotype: BORH; isotype: TI, a flower in the spirit collection) .

Thismia bryndonii is similar to T. mullerensis and T. lauriana in having a free perianth lobes equal in size and bifid stigmas, but differs in having two anther appendages and pale-orange streaks on the perianth tube with brown-orange transverse bars inside. Asymmetrical coloration of the perianth lobes is also unique to this species.

Small, achlorophyllous mycoheterotrophic herbs. Roots creeping, branched, ivory white. Stems simple, solitaryflowered, 1.5 cm tall, pale brownish white. Leaves and bracts reduced, up to 6 mm long, apex acute. Coloration of the perianth asymmetric, darker on one lobe. Flower perianth of 6 tepals fused to form a basal perianth tube, free apically; perianth tube actinomorphic, 9.0 mm long, 5.5 mm diameter, white with 12 thin, basally pale-orange streaks, leading down from each perianth lobe and from joints between the lobes. Brown-orange transverse bars throughout the perianth tube inside. Lobes triangular, 2 mm long, white or dark brown at the base, terminated by pale purplish brown tentacles 10–11 mm long. Annulus prominent, white. Filaments 6, flattened, borne on the thickened margin of the perianth tube, down-curved, free, ribbon-shaped, apically lobed, white, apically tinged with purple; stamen apically connate, forming an anther tube, 3.8 mm long; individual stamen bearing 2 anthers of 0.6 mm long; a round gland seen around the apex on the fused line between connectives; apex of stamen with 2 filiform appendages of 0.6 mm; style 0.7 mm; stigmas 3, bifid, dark purple, 1.3 mm long. Fruits not seen.

Notes:— In view of the classification of Jonker (1948), T. bryndonii appears to belong to sect. Euthismia Schlechter. (1921:31) in having a free inner perianth, spreading, creeping, and vermiform roots and belongs to subsect Odoardoa Schlechter (1921:31), in having perianth lobes equal in length and size. Only T. mullerensis Tsukaya & Okada (2005: 129) and T. lauriana Jarvie (1996: 259) share bifid stigmas in subsect. Odoardoa, and T. brydonii has two anther appendages. Thismia brydonii differs in having pale-orange streaks on the perianth tube with brown-orange transverse bars inside, differently sized perianth lobes (12–13 mm vs. 17 or 70 mm, respectively) and its slight asymmetric coloration of the perianth lobes, whereby one perianth lobe is darker than the other lobes. Asymmetry in the perianth tube is known in some species of Thismia , but T. brydonii is unique in having a symmetric perianth tube with asymmetric coloration.

Distribution: — This species was found in the understory of a dipterocarp forest and is only known from the type locality in the Maliau Basin, Sabah, Borneo.

Etymology:— The species name T. bryndonii was chosen in honour of our guide in the Maliau Basin Conservation Area, Bryndone Farone Bernard, who first discovered this new species on a botanical expedition.

Based on the observations, the following can be inserted into the key to species of Thismia in Flora Malesiana I, 4 ( Jonker 1948: 22) with modifications by Tsukaya et al. (2005), Chantanaorrapint (2012) and Dančak et al. (2013).

7. Stigmas bifid.

8. Anther appendages filiform, 2; perianth tube with longitudinal streaks and many transverse bars inside.

9. Perianth white with 12 pale-orange streaks and brown-orange transverse bars inside; lobes with tentacles 12–13 mm .............. ............................................................................................................................ T. bryndonii Tsukaya, Suetsugu et M.Suleiman

9. Perianth white with 12 brownish purple streaks and white transverse bars inside; lobes with tentacles ca. 17 mm ..................... ............................................................................................................................................... T. mullerensis Tsukaya et H.Okada

9. Perianth white with 12 white streaks and white transverse bars inside; lobes with tentacles ca. 70 mm ......... T. lauriana Jarvie

8. Anther appendages more than 3

10. Anther appendages 3

11. Transverse bars found only in the basal part of the perianth tube ................................................................... T. bifida M.Hotta

11. No transverse bars found in the perianth tube.................................................................................... T. filiformis Chantanaorr.

10. Anther appendages 4 12. Four filliform appendages; perianth lobes 7–18 mm ................................. T. hexagona Dančak, Hroneš, Kobrlová & Sochor

12. Two tooth-like appendages and two filiform appendages; perianth lobes 29–43 mm ................................................................ .............................................................................................. T. hexagona var. grandiflora Tsukaya, M.Suleiman & H.Okada

7. Stigmas not bifid...................................................................................................................... 13 (no. 10 in Tsukaya & Okada 2012)

Figures

FIGURE 1. Thismia bryndonii. A. Lateral view of the species flowers in its native habitat. Note the asymmetric coloration of the flower. B. Front view. C. Gross morphology of the whole plant with a flower opened to show the inside; scale in cm. D. Color and shape of stamens, pistil, and perianth tube in the living state. E. Stamens in their natural position. F. Stamens turned: g, gland; a, anther. G. Ovary and stigma. (E–G at the same magnification; scale bar, 2 mm.) Photographs (A, B) were taken in the Maliau Basin Conservation Area on 30 September 2016.