The genus Colura section Gamolepis (Lejeuneaceae, Marchantiophyta) in Malesian region, with the description of Colura sigmoidea Author Sangrattanaprasert, Jiroat Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand Author Chantanaorrapint, Sahut Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand Author Zhu, Rui-Liang text Phytotaxa 2019 2019-01-04 387 1 40 54 http://dx.doi.org/10.11646/phytotaxa.387.1.3 journal article 10.11646/phytotaxa.387.1.3 1179-3163 13725577 Colura verdoornii Herzog & Jovet-Ast, Rev. Bryol. Lichénol. 22: 288. 1953 . ( Fig. 6 ) Type: — MALAYSIA . Johore : Ophir Mountain, Fr. Verdoorn b2 ( holotype : JE !). Plants pale green, ca. 6 mm long; shoots 2–3 mm wide; irregularly pinnately branched, branches of Lejeunea - type . Stems 90–100 μm in diameter, in transverse section consisting of 7 cortical cells (24–40 × 20–30 μm) and 3 medullary cells (20–26 × 15–20 μm); ventral merophyte of stem 2 cells wide. Rhizoids numerous, fasciculate at base of underleaves. Leaves imbricate, spreading from stem at 60°–80° (–90°) angle. Lobes 0.96–1.4 mm long, 0.54–0.96 mm wide; dorsal margin entire to crenulate. Lobe cells thin-walled, trigones large, intermediate thickenings very distinct; marginal cells subquadrate to slightly rectangular, 22–30 × 20–28 μm; median cells hexagonal to slightly rectangular, 34–40 × 26–34 μm; basal cells rectangular to hexagonal, 24–48 × 14–20 μm. Cuticle smooth. Oil bodies 15–35 per cell, homogenous to very finely segmented, ellipsoid, 3–6.4 × 2.4–3.2 μm. Lobules narrowly tubular, flaring toward sac, 1.3–1.8 mm long. Lobule sacs elliptic to ovate, strongly inflated, 0.5–0.6 mm long, 0.24–0.3 mm wide, sac surface mamillose, apex acute, ending in apical crest consisting of (1–) 3–5 cells, rarely entire. Valves intermediate-type, elliptic, oblique at base, 76–100 × 54–70 μm, composed of one circle of 16–24 hyaline marginal and 14–27 median cells with one basal median cell, basal median cell adnate with a hinge cell not forming a sigmoid curve in outline. Hyaline papillae spherical to bulbous, 12–14 μm in diameter. Valve frames outline semicircular with uniseriate cells, ca. 100 μm wide. Underleaves distant, deeply bilobed, sinus obtuse; lobes lanceolate, 160–200 × 40–60 μm, 7–9 cells long, 3–4 cells wide at base; margin entire. Asexual reproduction by discoid gemmae, occurring on lobule sacs; gemma cells subquadrate to isodiametric, consisting of 26–29 cells. Dioicous . Androecia terminal or intermediate on main stems and lateral branches; male bracts in 3–5 pairs, hemisphere, apical keels crenulate with one projecting cell row, free margin entire, hypostatic; bract lobes oblong to semicircular, 304–400 × 160–320 μm; bract lobules oblong to semicircular, 320–344 × 160–176 μm, antheridia 2 per bract; male bracteoles bilobed, 50–70 × 70–90 μm. Gynoecia terminal on lateral branches with 1 pycnolejeunoid innovation; female bracts obovate to oblong, 760–1000 × 320–440 μm, apical keels entire, rarely crenulate with one projecting cell row; bract lobules narrowly oblong, 700–800 × 40–96 μm; female bracteoles subquadrate to semicircular, ca. 100 × 80 μm, apex obtuse to emarginate. Perianths oblong, 1.3–1.84 mm long, 0.4–0.6 mm wide, with 3–5 keels; keels short, entire to mamillose; beak 1–2 cells long. Sporophytes . Setae articulate, 9–11 cells long; in transverse section with 4 inner and 12 outer cells. Capsules slightly spherical, 320–370 μm in diameter, splitting to ± 3/4 of its length into four erect valves after dehiscence; capsule valve 344–400 × 216–240 μm; wall 2–3 stratose, hyaline. Outer layer of capsule valve apex formed by 1 quadrate cell; cell of upper half of valve slightly rhombic, large, thin-walled; hinge butterfly-shaped, hinge cells rectangular to subquadrate, smaller than cells of upper half, thin-walled; margin formed by 1 row of rectangular cells. Inner layer of capsule valve cells in centre rectangular, walls with nodular thickenings; marginal cells of upper half quadrate to rectangular, walls nodulose, formed by 2 rows, marginal cells of lower half rectangular, walls smooth; basal cells subquadrate with smooth walls. Elaters of 2 types : marginal and additional; marginal elaters 22 per capsule, each valve contains 4 or 5 upper marginal elaters and 2 or no lower marginal elaters; upper marginal elaters attached to upper half of valve margin by one end, 256–328 μm long, 12–24 μm wide, hyaline, with irregular thickening, end attached to valve margin rounded, not expanded, free end dilated; lower marginal elaters attached to valve at both ends (near and parallel to basal margin), 186–216 μm long, 14–20 μm wide, hyaline, with irregular to annular thickenings, upper end narrowly tapered, lower end obtuse; additional elaters 4 per capsules (1 per each valve), 240–304 μm long, 8–14 μm wide, hyaline, with irregular thickening, attached along their whole length to median part of valve. Spores green, irregular-oblong or elongate-rectangular in shape, 46–100 × 26–30 μm; spore surface covered with irregular lamellae; sporelings Lejeunea - type . Habitat and ecology: — Colura verdoornii usually grows on living leaves in lowland to montane rain forests at altitude between 500 and 1800 m ; however, it is often found on twigs at the summit of the mountain as well. Distribution: — Indonesia , Malaysia ( Jovet-Ast, 1953 , 1958 ), new to Thailand . Selected specimens examined: — INDONESIA . East Kalimantan : Kutai peak of Balikpapan , 1000 m , 18 July 1952 , W . Merjer B 2618 d ( L ) ; West Java : Cianjur regency, Cipanas District , Cibodas Botanical Garden , ca. 1275 m , 9–10 August 2015 , Sangrattanaprasert 383/15 B ( PSU ) . MALAYSIA . Pahang : Fraser’s Hill , 1400 m , 18 March 1952 , Henderson s.n. ( L ), 8–11 April 2014 , Sangrattanaprasert 79/14 , 80/14 B ( PSU ) ; Genting Highland , Gohtong Jaya , road to the resort area, 820 m , 9 September 2006 , Cheah 48 , 53 ( KLU ) . THAILAND . Nakhon Si Thammarat : Khao Nan National Park , 10–12 August 2007 , Sukkharak & Seelanan 485 , 487 , 513 , 519 ( BCU ) ; Khao Luang National Park , 08°32ʹ31.95ʺ N , 099°44ʹ13.98ʺE , 1682–1800 m , 20–23 April 2015 , Sangrattanaprasert 373/15 ( PSU ) ; Phatthalung : Kong Ra , Khao Loan , 07°26ʹ45.33ʺN , 99°52ʹ31.64ʺE , 942 m , 28 May 2017 , Chantanaorrapint & Suwanmala 1079 B , 1100 B ( PSU ) ; Songkhla : Tone Nga Chang Waterfall , 06°56ʹ43.91ʺN , 100°13ʹ16.43ʺE , 500 m , 4 October 2014 , Sangrattanaprasert 204/14 B ( PSU ), 836 m , 1 February 2015 , Sangrattanaprasert 260/15 B ( PSU ) ; Surat Thani : Ko Pha-ngan , Khao Rha , 09°45ʹ38.96ʺN , 100°01ʹ13.96ʺE , 600 m , 3 June 2014 , Sangrattanaprasert 151/14 B ( PSU ) ; Trang : Khao Chedyod , 07°19ʹ18.80ʺ N , 99°54ʹ40.48ʺE , 1040–1070 m , 2 May 2014 , Sangrattanaprasert 120/14 E ( PSU ) ; Yala : Ban Chulabhorn Pattana 10, 05°49ʹ04.40ʺN , 101°01ʹ50.20ʺE , 570 m , 15 June 2013 , Chantanaorrapint & Promma 2549 C ( PSU ) . Taxonomic note: — Colura verdoornii shows extreme variations in leaf lobe shapes and sizes. It is easily recognized by the presence of apical crest on lobule-sac apices, small lobule sacs 1/3 as long as lobule length, and hexagonal to slightly rectangular shape of leaf cells. Colura verdoornii may be confused with C . valida , particularly viewed under the hand lens. The latter, however, differs from the former in the lack of laminar crest on the apex of lobule-sac, large ovate-elliptic valves consisting of 44–56 cells, and underleaf lobes 12–16 cells long and 6–9 cells wide.