identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
F613211E82055AD09E17E1AA6B42E48D.text	F613211E82055AD09E17E1AA6B42E48D.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Radula rheophila Promma & Chantanaorr. A - C. Portions 2026	<div><p>Radula rheophila Promma &amp; Chantanaorr. sp. nov.</p><p>Figs 2, 3</p><p>Type material.</p><p>Thailand. • Songkhla: Ton Nga Chang Wildlife Sanctuary, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.218216&amp;materialsCitation.latitude=6.944895" title="Search Plazi for locations around (long 100.218216/lat 6.944895)">Ton Nga Chang Waterfall, lowland evergreen forest</a>, 6°56.6937'N, 100°13.093'E, 483 m elev., on wet rocks along stream, 11 Feb 2018, S. Chantanaorrapint 3045 (holotype: PSU!; isotypes: BKF!, HSNU!) .</p><p>Diagnosis.</p><p>Radula rheophila resembles R. novae-hollandiae Hampe in lobule shape but differs in having ovate to broadly ovate leaf lobes with a broadly obtuse to rounded apex and entire margin.</p><p>Description.</p><p>Plants yellowish-green to bright green when fresh, yellowish-brown in dry condition. Shoots up to 15 mm long, 1.56–2.30 mm wide; irregularly and densely pinnately branched, obliquely spreading; microphyllous and amentulose branches absent. Stems 156.5–280.0 µm diameter in transverse section, 8–14 cell rows across, with 40–80 rows of medullar cells, 24–30 rows of cortical cells, cortical cells as large as the medullary cells, 10–36 µm wide; cell walls pale brown to yellowish-brown, exterior cortical wall heavily and evenly thickened, interior cortical cell wall and medullary cell wall thin medially and thickened at the angles by concave trigones that make the cells circular in outline. Rhizoids brown, rhizoid-initial area convex. Leaf lobes loosely imbricate to slightly remote, widely spreading, ovate to broadly ovate, 0.75–1.10 mm long, 0.66–0.91 mm wide, apex broadly obtuse to rounded, margin entire, dorsal base strongly arched and slightly covering the stem to covering the stem ca. 1 / 2 of the stem-width in dorsal view. Leaf lobe marginal cells 7.5–17.5 × 12.5–17.5 µm, median cells 14.5–28.0 × 16.5–24.3 µm, basal cells 17.5–34.5 × 16.0–36.5 µm, thin-walled with indistinct or minute trigones; cuticle smooth. Oil bodies 2–3 per cell, grayish brown, ovoid or ellipsoidal, 10.9–16.4 × 7.0–9.3 µm, finely botryoidal. Leaf lobules remote, longitudinally rectangular or ligulate when large, broadly transversely rhombic or rectangular when small, 1 / 3–2 / 5 of the lobe-length, 375–678 mm long, 260–388 mm wide, apex obtuse or rarely emarginate, free exterior margin straight, or slightly sinuate, parallel or slightly inclined towards stem, free antical margin obliquely straight then arched to lobule free interior margin, free interior margin arched and slightly covering the stem to ca. 1 / 2 of the stem-width, line of insertions longitudinal with the stem, nearly straight or slightly arched, carinal region not or slightly inflated, keel straight to slightly sinuate, extending at angles of 40–50 ° with the stem, sinus wide or none. Slime papillae of leaf lobule usually 3, one situated on the lobule-apex, rounded to ovoid and sunken into a distinct notch, the other two near the base of the free interior margin of leaf lobule (on margin above the top of the stem insertion) at intervals, obovoid or short pyriform (sometimes nearly rounded). Asexual reproduction not seen. Sexuality dioicous (androecia not seen)?. Gynoecia terminal on main shoots and lateral branches, with 1–2 subfloral innovations; bracts in 2 or 2.5 pairs, often one below the subfloral innovations, subsymmetrical, or sometimes asymmetrical, imbricate, bract-lobe oblong-elliptic (upper) or ovate (lower), 1204–1264 µm long, 715–837 µm wide, apex rounded, slightly incurved, margin entire, bract-lobules ovate, one-thirds (lowest) to two-thirds (upper) the lobe area, apex obtuse to rounded, sometimes recurved, margin entire, keel slightly arched; perianths not seen. Sporophytes not seen.</p><p>Etymology.</p><p>The specific epithet “ rheophila ” derives from the Greek rheo- meaning “ flowing ” and - phila meaning “ loving, ” referring to the species’ affinity for habitats associated with running water.</p><p>Habitat and ecology.</p><p>Radula rheophila typically grows on wet rocks, roots, and soil along streamside in lowland evergreen forest, at elevations ranging from 75 to 490 m (Fig. 4 A). The species prefers constantly moist and shaded microhabitats, often in association with other liverworts and mosses.</p><p>Distribution.</p><p>Radula rheophila is currently known from Thailand and Brunei. However, it may also occur in other areas in southern Thailand and Peninsular Malaysia as well, where similar ecological conditions prevail.</p><p>Additional specimens examined.</p><p>Thailand. • Songkhla: Ton Nga Chang Wildlife Sanctuary, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.21912&amp;materialsCitation.latitude=6.9450583" title="Search Plazi for locations around (long 100.21912/lat 6.9450583)">Ton Nga Chang Waterfall</a>, 6°56.7035'N, 100°13.147'E, 490 m elev., 21 Mar 2014, S. Chantanaorrapint &amp; C. Promma 3503 (HSNU, PSU: B 01415) , S. Chantanaorrapint &amp; C. Promma 3504 (HSNU, PSU: B 01416); S. Chantanaorrapint &amp; C. Promma 3875 (PSU); • 6°56.6937'N, 100°13.093'E, 483 m elev., 11 Feb 2018, S. Chantanaorrapint 3044 (HSNU, PSU); • 6°56.7243'N, 100°13.2778'E, 466 m elev., 21 Oct 2025, C. Promma et al. 2025 1021-10; • 6°56.7293'N, 100°13.2707'E, 463 m elev., 21 Oct 2025, C. Promma et al. 2025 1021-11 (PSU); • 6°56.7295'N, 100°13.2758'E, 465 m elev., 21 Oct 2025, C. Promma et al. 2025 1021-12 (PSU); • 6°56.6947'N, 100°13.0895'E, 478 m elev., 21 Oct 2025, C. Promma et al. 2025 1021-24 (PSU) . Brunei Darussalam. • Temburong: <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=115.158325&amp;materialsCitation.latitude=4.5477467" title="Search Plazi for locations around (long 115.158325/lat 4.5477467)">Kuala Belalong Field Studies Centre of University Brunei Darussalam, the opposite river</a>, 4°32.8648'N, 115°9.4995'E, 78 m elev., 16 Dec 2015, C. Promma 20151216-1 (HSNU) .</p></div>	https://treatment.plazi.org/id/F613211E82055AD09E17E1AA6B42E48D	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Promma, Chatchaba;Zhu, Rui-Liang;Chantanaorrapint, Sahut	Promma, Chatchaba, Zhu, Rui-Liang, Chantanaorrapint, Sahut (2026): Radula rheophila, a new species of Radula (Radulaceae) from Thailand and Brunei Darussalam. PhytoKeys 271: 205-218, DOI: 10.3897/phytokeys.271.181229
