Thysananthus comosus Lindenberg ex Lehmann (1844: 25)

Sukkharak, Phiangphak, 2015, A systematic monograph of the genus Thysananthus (Lejeuneaceae, Marchantiophyta), Phytotaxa 193 (1), pp. 448-450 : 448-450

5. Thysananthus comosus Lindenberg ex Lehmann (1844: 25) . Lejeunea comosa (Lindenb. ex Lehmann) Mitten (1861: 109) . Lectotype (designated by Verdoorn 1934a): MALAYSIA. Penang: Pulo Penang, 1824, Wallich s.n. (lectotype W; isolectotypes BM!, U!).

Lejeunea (subg. Thysanolejeunea) dissoptera Spruce (1884: 108) . Thysananthus dissopterus (Spruce) Stephani (1890: 4) . Type: “ Guiana ”, ex hb. Hooker (holotype MANCH; isotypes BM, G, fide Gradstein, 1994, GOET!).

Plants dioicous, with projecting growth, turning upwards and becoming ascending to erect, pale green, becoming dark brown in the older portion in the field, reddish brown in herbarium specimens, up to 2.8 cm long × 2 mm wide. Stems rather rigid; ventral merophyte 8–9 cell rows wide; stem in cross section orbicular, 167–180 µm high × 130–148 µm wide, 8–12 cell layers high, composed of 25–27 epidermal cells surrounding 49–55 medullary cells, epidermal cells as large as medullary cells. Leaves imbricate, when dry suberect and convolute, when moist weakly convex, apical part plane, not recurved; dorsal lobe asymmetrically ovate, 0.9–1 × 0.7–0.9 mm, apex obliquely mucronate, margins entire or serrate (Schiffner s.n.), dorsal base auriculate, auricle 112–137 × 75–88 µm, ventral margin incurved 1/2 × leaf length; cells elongate-hexagonal with acute ends, vitta absent, marginal cells 10–20 × 7.5–15 µm, median cells 22.5–30 × 10–15 µm, basal cells 32.5–40 × 15–22.5 µm, trigones cordate, often

26 • Phytotaxa 193 (1) © 2015 Magnolia Press

SUKKHARAK coalesced, intermediate thickenings 0–1 per cell; oil bodies 2–4(–5) per cell. Lobules oblong, 0.3–0.4 × 0.1–0.2 mm, 1/4–1/3 × lobe length; appendage on surface of lobule base not developed; keel without appendage; lobule apex oblique, free margin continuing into the ventral lobe margin, apex entire or with 1–2 triangular teeth, the first tooth consisting of 3 cells, being 2 cells wide at base, apex of one cell; the second tooth consisting of 3 cells, being 2 cells wide at base, apex of one cell, often absent. Underleaves imbricate, flat, broadly obovate, 0.5–0.6 × 0.6–0.7 mm, 4–5 × stem width, apex truncate, plane, margins entire to serrate, bases cuneate, underleaf bases adnate with leaves on one side, on left-hand side for right branches and right-hand side for left branches; cells 17–22 × 7.5–10 µm. Androecia terminal-intercalary on lateral branches, bracts and bracteoles in 4–7 pairs (15–21 in Wood 1380), bracts hypostatic, 0.8–0.9 × 0.6–0.7 mm, apex mucronate, margins entire; antheridia 2 per bract. Gynoecia with one lejeuneoid innovation forming a monochasial pattern; lobe ovate, 1.1–1.3 × 0.7–1 mm, apex apiculate, margin in upper 1/3 with triangular teeth, the teeth consisting of 3–5 cells, being 2–3 cells wide at base and ending in a row of 1–2 cells; lobules broadly ovate, 1/2 × lobe length, apex apiculate to obscurely bifid, margin with triangular teeth, the teeth consisting of 5–6 cells, being 2–3 cells wide at base and ending in row of 2–3 cells; bracteoles spathulate, 1.1–1.2 × 0.7–0.8 mm, apex emarginate, margin with triangular teeth, the teeth consisting of 5–9 cells, being 2–3 cells wide at base and ending in a row of 2–3 cells, margins recurved. Perianths obovate, 0.9–1 × 1.3–1.4 mm long, keels in upper 1/2 with numerous laciniate teeth, the teeth consisting of 5–9 cells, being 2–3 cells wide at base and ending in a row of 3–6 cells; beak 25 × 30 µm (4–5 cells) in length. Fig. 13 .

Additional illustrations:— Fulford (1941, p. 41, Figs. 41–51).

Distribution and ecology:— Indomalesia; sea level up to 500 m; on bark of living and fallen trees in mangrove forests, lowland rain forests (secondary forest), and also on rock in coastal forests. Fig. 5G .

Representative specimens:— Seychelles. MAHÉ ISLAND: Beau Vallon, Dans Iles cliff walk, Norkett 18167 (BM); forest above Le Niol reservoir, Norkett 16584 (BM, JE).— PRASLIN ISLAND: Grand’ Anse, Vallée de Mai Nature Reserve, Norkett 18426 (BM, JE), Pócs 9358/B (EGR, GOET).

India. ANDAMAN AND NICOBAR ISLANDS: Andaman Islands, Port Blair, 1893, Man s.n., ex hb. Levier 740 (G); Nicobar Island , Katschall , 10 February 1975, Kurz s.n. (W 3 packets) . Thailand. NAKHON SI THAMMARAT: Mt. Khao Luang , 24 February 2009, Chantanaorrapint s.n. ( PSU) ; Mt. Khao Nan Yai , Sukkharak 334 ( BCU) .— PANG NGA: Khao Luk National Park , Porn-Sook-Sawang 15 ( BCU) ; Sri Pang Nga National Park , Chantanaorrapint 2121 ( PSU) ; mangrove forest site 3, Boonkerd 5 ( BCU) ; mangrove forest site 6, Thaithong 1130 ( BCU) .— PHUKET: 8° N 98°20' E, Touw 11201 (L).— SONGKLA: Ton Nga Chang, 17 August 2009, Inuthai s.n. ( PSU) . Vietnam. KHÀNH HÒA: Nha trang, 11 April 1958, Tixier s.n. ( PC) . Malaysia. JOHOR: Kota Tinggi, Sinclair 10898 ( BM) ; Kampung Selai , Mohamed & Sabda 8 ( KLU) .— KEDAH: Ulu Muda Forest Reserve , Kien-Thai 3126 ( KLU) .— PENANG: without location, without date, Hooker s.n. (G) .— PERAK: 4°51' N 100°44' E, Mohamed & Kien-Thai 4851 ( KLU) ; Pangkor Island, Sukkharak 730 ( BKF, GOET) .— SABAH: Kalabakan , Wood 1380 (L) .— SARAWAK: Banting , “Beccari 1867” ( PC) .— SELANGOR: Kajang , Mohamed 1711 ( KLU) . Singapore. Boekit Timah, November 1893, Schiffner s.n., Hep. Sel. Crit. Verdoorn 280 ( BR, C, G 2 packets, PC, SING) .

Indonesia. KALIMANTAN: Kapuas river, Winkler 3282/a ( GOET); East Kalimantan, along Bongan river , Meijer B 1197c (L) .— JAVA: Bogor ("Buitenzorg"), 1893–1894, Schiffner s.n., Hep. Sel. Crit. Verdoorn 281 ( BR, C, G 2 packets, GOET, L 2 packets, PC, S, SING, U) .— SUMATRA: West Sumatra, Padang, without date, Pieper s.n. (S), Schild 117 (W); Mentawei Island , van Borssum Waalkes 2698 (L 2 packets); Talang Betutu, “Lutingh” z.s.12/1 (L) .

Philippines. BUKIDNON: Impalutao B. F. D. reforestation project, Onraedt 85.P.11043 ( BR) .— ZAMBALES: without location, Curran & Merritt 8192 (G); without location, Cuming 1488, 2110 ( BM) . Federated States of Micronesia. POHNPEI: Mt. Nanlaut, 28 June 1949, Glassman s.n. (G) . Papua New Guinea. EAST NEW BRITAIN: Nakanai Mts., Streimann 40422 ( JE, NICH) .— MILNE BAY: near Mita, “February, 1895”, Micholitz s.n. (G) .— MOROBE: Labutali village, Bellamy 178 ( U) .

Taxonomic notes:— Thysananthus comosus is morphologically most similar to T. gottschei , from which it differs mainly by the leaves, which are weakly convex when moist (strongly convex in T. gottschei ) and underleaves, which are flat obovate and truncate (slightly squarrose, broadly spathulate and rounded in T. gottschei ).

Thysananthus comosus was described by Lindenberg in 1844 based on two specimens, one from Asia (“Pulo Penang”) and one from South America (“ Guiana ”). Spruce (1884) considered the two specimens different and named the South American plant Lejeunea dissoptera (= T. dissopterus ). Fulford (1941), however, considered T. dissopterus as a synonym of T. comosus . Gradstein (1994) found that the two specimens are identical except that

Thysananthus ( Lejeuneaceae , Marchantiophyta) Phytotaxa 193 (1) © 2015 Magnolia Press • 27 the material from Pulo Penang is male whereas the plants from Guiana are female; he proposed that T. comosus be excluded from the neotropical flora. I have found both male and female plants in the type collection from Pulo Penang and agree with Gradstein. Reasons for the exclusion were that if T. comosus occurs in the Guianas, which have been well collected in recent times, it should have been rediscovered. In addition, there is no duplicate of the Brazilian specimen (“Janiai”) in the Spruce herbarium and the locality of this specimen is obscure ( Gradstein 1994).

Thysananthus comosus varies in the dentation of leaves and underleaves, which is entire to strongly serrate, and the number of leaf lobule teeth as seen in T. amazonicus . Molecular analysis has resolved the species as polyphyletic ( Sukkharak et al. 2011b).

Figures

FIGURE 5. Distribution of Thysananthus species. A. Thysananthus amazonicus (Spruce) Schiffn. B. Thysananthus spathulistipus (Reinwardt, Blume & Nees) Lindenb. C. Thysananthus convolutus Lindenb. D. Thysananthus mollis Steph., E. Thysananthus pancheri (Steph.) Hürl. F. Thysananthus anguiformis (Hook.f. & Taylor) Taylor ex Gottsche, Lindenb. & Nees G. Thysananthus comosus Lindenb. H. Thysananthus fruticosus (Lindenb. & Gottsche) Schiffn. I. Thysananthus aculeatus Herzog. J. Thysananthus appendiculatus Steph. K. Thysananthus montanus Gradst., X.-L. He & Piippo. L. Thysananthus retusus (Reinw., Blume & Nees) B.M.Thiers & Gradst. M. Thysananthus gottschei (Jack & Steph.) Steph. N. Thysananthus ciliaris comb. nov. O. Thysananthus discretus Sukkharak & Gradst.

FIGURE 13. Thysananthus comosus Lindenb. A. Portion of shoot, ventral view. B–C. Leaves, ventral view. D–E. Underleaves, ventral view. F. Female bracts, ventral view. G. Female bracteole, ventral view. H. Perianth, dorsal view. I. Perianth, ventral view. J. Leaf apex. K. Margin cells of leaf lobe. L. Median cells of leaf lobe. M. Basal cells of leaf lobe. N.–P. Leaf lobule apices. Q. Cross section of stem. R. Oil bodies (A, C, E–Q from the lectotype, B, D from Schiffner s.n. (GOET), R from Sukkharak 730 (BKF, GOET)).