Scaphochlamys calcicola Poulsen & Searle (2005: 29)

Hin, Ooi Im, Kalu, Meekiong & Yeng, Wong Sin, 2017, A review of Scaphochlamys (Zingiberaceae) from Borneo, with description of eleven new species, Phytotaxa 317 (4), pp. 231-279 : 246-248

8. Scaphochlamys calcicola Poulsen & Searle (2005: 29) . ≡ Borneocola calcicola (A.D. Poulsen & R.J. Searle) Sam in Sam et al. (2016: 46). Type:—MALAYSIAN BORNEO. Sarawak: Kuching Division, Bau area, Gunung Tai Ton, 1°24’N; 110°8’E, 50 m, in a recently deforested limestone gorge, 20 June 2003, A.D. Poulsen, Jugah & K. Clausager 2022 (holo SAR!, iso AAU, E, K!, L!), Figure 8

Terrestrial, perennial, rhizomatous herbs, to 30–60 cm tall. Rhizome horizontally creeping above the ground, robust, c. 7 mm in diameter when dried, sometimes forking, with well-developed anchoring roots (not stilted). Elements 2–20 cm apart, distinctly 1-foliate; petiole (measured from the base of the shoot because the ligule is often hard to establish) 10–39 cm long, canaliculate, leafless sheath 3–5, the longest to 18 cm, cream at base, flushed green towards apex, becoming brown and papery with age, shredding, these completely hide the much shorter leaf sheath and ligule of the leaf; leaf sheath to 3 cm long, margin thin and densely ciliate terminating in an obscure ligule; ligule to 5 mm (when fresh), bilobed, membranous; lamina 15–37 × 9–18 cm, slightly asymmetric, broadly elliptic to lanceolate, margin plicate, base rounded to slightly cordate and attenuate; apex distinctly acuminate to c. 1 cm, adaxial surface plain green, abaxial surface villose (up to 1 mm long, appressed, white hairs, scattered throughout the abaxial surface but most dense near and on the sides of the midrib), very pale green. Inflorescence derived from near the leaf base inside the leafless sheaths, 7–10 cm long, bilaterally flattened, 1.5–2.0 × 0.5–0.6 cm deep, tapering towards a pointed apex, with 8–13 bracts arranged distichously and 0.3–0.7 cm apart on an elongated spike; peduncle to 1.5 cm, slender, glabrous, hidden at base of the leaf; bract 2.5–3.2 × 0.9 cm near the base, held stiffly upright, boat-shaped, apex acute, edges involute and overlapping, pale green, outer surface glabrous or covered in short spiky pubescent, each bract subtending 2–3 flowers; bracteole 2.0– 3.3 cm (first; second and third decreasing in size), 2-keeled, first bracteole generally longer and opposite to the bract, wrapped tightly around the flower(s), slit to the base, edges overlapping, covered in short spiky pubescent; calyx with ovary 12–13 mm long, fissure c. 4 mm, with rounded to acute, irregularly tridentate apex with a scattering of short spiky hairs, otherwise glabrous; floral tube 2.4–4 cm long, glabrous; corolla lobes 1.5 × 0.5 cm, linear, apex mucronate and hooded, white; staminodes 1.2 × 0.3–0.4 cm, oblong, apex obtuse, papillose; labellum 1.4–1.7 × 0.9–1.1 cm, spathulate, apex bilobed, indented 3–4 mm, white with pale yellow-green median band, lobes overlapping; stamen 11–12 mm; filament 5–7 × 2 mm, anther thecae 4–5 × 1.5 mm, not spurred, dehiscing for their entire length; crest rounded, to 2 mm; stigma 1 mm across, club-shaped with two dorsal knobs, ostiole ciliate, forward-facing; ovary 2 mm, glabrous, epigynous glands 4–5.5 mm, bilobed, needle-shaped. Fruit and seeds not seen.

Distribution & ecology: — Endemic to Borneo in lowland forest. So far only documented from Bau, southwest Sarawak, where it is exclusive on forested Karst limestones ( Poulsen & Searle 2005).

Additional specimens examined:— MALAYSIAN BORNEO. Sarawak: Kuching Division , Bau, Seromah, 01°22’37.2”N, 110°11’33.9”E, 34 m, 12 January 2014, I.H. Ooi & K. Jeland OIH81 (SAR) ; Gunung Tai Ton , 30 October 2002, G. Connie et al. SBC 3749 (SING) .

Conservation status:—The conservation status of this species is Vulnerable (VU) meeting criteria B.1.a., B.1.b.(v), B.2.a., B.2.b.(v), D.1., and D.2. Although locally common within limestone areas in Bau, the habitat could be easily destroyed by quarrying activities. Since S. calcicola is an obligate limestone mesophyte in deep litter humus pockets, the species is justified to be under the category VU.

Discussion:—This species is the only Scaphochlamys species in Borneo with distichously arranged inflorescence and therefore its inclusion in Scaphochlamys was slightly doubtful ( Poulsen & Searle 2005). In this study, its placement in Scaphochlamys is confirmed by the observation of acroscopic flowering sequence. Poulsen & Searle (2005) stated the species is unique in having spurless anthers. However, spurless anthers were also found in many other Bornean Scaphochlamys species.

Figures

FIGURE 8. Scaphochlamys calcicola. A. plant in habitat, note lamina abaxial surface. B. plant in habitat, note lamina adaxial surface. C. inflorescence, note distichous arrangement. D. young infructescence. E. infructescence, artificially opened to show fruit. F. flower, front view. G. flower, side view. All from OIH81.