Thysananthus pancheri (Gottsche ex Steph.) Hürlimann (1989: 167)

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

publication ID	https://doi.org/ 10.11646/phytotaxa.193.1.1
persistent identifier	https://treatment.plazi.org/id/73083D48-FF81-BF0D-FF17-39CEFA3E944C
treatment provided by	Felipe
scientific name	Thysananthus pancheri (Gottsche ex Steph.) Hürlimann (1989: 167)
status

Treatment

11. Thysananthus pancheri (Gottsche ex Steph.) Hürlimann (1989: 167) View in CoL . Mastigolejeunea pancheri Gottsche ex Stephani (1912a: 771) . Type: NEW CALEDONIA. without location, without date, Pancher 591 (isotypes PC 3 packets!); Icon. Steph. nr. 7448.

Plants dioicous, with projecting growth, turning upwards and becoming ascending to erect, yellowish brown to reddish brown to blackish brown in herbarium specimens, up to 1.8 cm long × 1.9–4 mm wide. Stems rather rigid; ventral merophyte 7–9 cell rows wide; stem in cross section orbicular-subelliptic, 159–230 µm high × 159–176 µm wide, 9–10 cell layers high, composed of 25–33 epidermal cells surrounding 42–47 medullary cells, dorsal epidermal cells larger and somewhat thinner-walled than medulla and ventral epidermal cells. Leaves imbricate, when dry suberect and convolute, when moist strongly convex and ventrad, apical part turned to the ventral side, recurved; dorsal lobe asymmetrically broadly ovate, 1.1–1.6 × 0.9–1.2 mm, apex rounded or acute-apiculate, margin entire, dorsal base auriculate, auricle 50–82 × 25–75 µm; cells elongate-hexagonal with acute ends, vitta absent, marginal cells 7.5–12.5 × 10–15 µm, median cells 22.5–27.5 × 12.5–20 µm, basal cells 25–45 × 17.5–25 µm, trigones cordate, often coalesced, intermediate thickenings 0–1 per cell; oil bodies unknown. Lobules

SUKKHARAK rectangular, 0.6–0.7 × 0.3–0.4 mm, ± 1/2 × lobe length; appendage on surface of lobule base not developed; keel without appendage; lobule apex truncate to oblique, free margin shortly continuing into the ventral lobe margin or not, apex with one triangular to narrow elongate tooth, the tooth consisting of (1–)6–12 cells, being 1–4 cells wide at base and ending in a row of 1–3 cells. Underleaves imbricate, slightly squarrose, broadly obovate, 0.5–0.8 × 0.6–1.2 mm, 3–6 × stem width, apex broadly rounded to truncate, margin entire, 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 22.5–17.5 × 7.5–10 µm. Androecia terminal-intercalary on lateral branches, bracts, and bracteoles in 3–8 pairs, bracts hypostatic and epistatic, 0.5–0.8 × 0.4–0.6 mm, apex acute, margins entire; antheridia 2 per bract. Gynoecia with one lejeuneoid innovation forming a monochasial pattern; lobe ovate, 1.1–1.4 × 0.5–0.7 mm, apex apiculate, margin entire; lobules broadly ovate, 1/2 × lobe length, apex apiculate, margin entire; bracteoles obovate, 1–1.2 × 0.5–0.7 mm, apex truncate, margins entire, slightly recurved. Perianths oblong, 1.3–1.4 × 0.5–0.8 mm, keels in upper 1/3 with short to long, laciniate teeth, the teeth consisting of 4–11 cells, being 2–3 cells wide at base and ending in a row of 2–6 cells; beak 57–112 µm (6–8 cells) in length. Fig. 22 View FIGURE 22 .

Distribution and ecology:— Endemic to New Caledonia; 40–1100 m; on bark in Canariellum sp. , Leucopogon sp. , and Spermolepis sp. forests. Fig. 5E View FIGURE 5 .

Representative specimens:— New Caledonia. NORTH: Oua Tilou, Baumann-Bodenheim 12421a (G, GOET); Mt. Ignambi, Hürlimann 2864 (GOET, U); Nehoue, Kee 36864 (PC); Pinjen, Kee 30858 (NICH).— SOUTH: Mt. Koghis, 1913, Franc s.n. (JE); Rivière Bleue, Hürlimann 10864 (GOET), 2665a (G, GOET); Rivière Blanche, Baumann-Bodenheim 13949 (G, GOET); Boulari valley, Hürlimann 2304a (G, GOET), 2303 (G, GOET, PC, U); ramp north-western of Mt. Quitchambo, Hürlimann 9343 (G, GOET); Mtge. des Sources, Hürlimann 2206 (G, PC, U), Kee 44013 (PC); Quinné valley of Mt. Dzumac, Hürlimann 2624 (G, GOET, PC, U), 2463 (GOET, PC, U); north-western of Mt. Natégou, Hürlimann 2279, 2292 (G, GOET, U), 2289a (GOET, PC, U); Kouébuni, Hürlimann 2250 (GOET, U), 2249, 2255, 2256 (G, GOET, U), 2252 (G, U), 2260b (GOET, U); Kouvelée Mts., Hürlimann 2453 (GOET, U); Koéalagoguamba, Hürlimann 2584a (G, GOET, U); “Marais Kiki”, Baumann-Bodenheim 6307c (GOET); summit of Oua Tilou, Baumann-Bodenheim 12424 (GOET); “southern woodland”, Guillaumin & Baumann-Bodenheim 11713a (GOET), 11703, 11704 (G, GOET, U); Rivière Voh, Guillaumin & Baumann-Bodenheim 12165 (G, GOET); Yaté, Mckee 42653 (PC), Hürlimann 2014 (GOET, U), 2279 (U); Pic Pembai, 1909, Le Rat s.n. (L).

Taxonomic notes:— Thysananthus pancheri may be confused with T. gottschei but the latter species has epidermal cells as large as medullary cells, spathulate underleaves and a toothed female involucre. Thysananthus pancheri is also rather similar to Mastigolejeunea calcarata , which occurs in northern Australia and in the central Pacific region but is not yet known from New Caledonia (see Thiers & Gradstein, 1989, for description). These two species can be separated by the different shape of their leaf lobules, which are broader and shorter rectangular in T. pancheri , being 0.3–0.4 mm wide and 1.5–2 × longer than wide (0.2–0.3 mm wide and 2–2.5 × longer than wide in M. calcarata ). In addition, the perianth keels in T. pancheri are ciliate and the male bracts are hypostatic or epistatic, whereas M. calcarata has smooth perianth keels and the male bracts are always epistatic.

Incongruence between plastid and ITS data and the larger plant size in one sample of Thysananthus pancheri led to the first report of a hybrid in Lejeuneaceae , and the first one in liverworts inferred from phylogenetic data ( Sukkharak et al. 2011b; Fig. 6 View FIGURE 6 ). In the cpDNA phylogeny ( Fig. 7A View FIGURE 7 ) T. pancheri sample 2 is sister to T. pancheri sample 1, and both samples are placed in a well-supported clade with T. anguiformis in the cpDNA phylogeny. In contrast, in the nuclear ITS tree ( Fig. 7B View FIGURE 7 ) T. pancheri sample 2 is sister to the T. appendiculatus-T. discretus clade with significant support. The plastid phylogeny concurs with the current species circumscription, whereas the ITS phylogeny is probably the deviating one as T. pancheri is morphologically well separated from T. appendiculatus and T. discretus . However, further analyses including chromosome counts and measurements of DNA contents are necessary to test the hybridization hypothesis and to determine possible polyploidy of T. pancheri sample 2.