Thysananthus convolutus var. laceratus (Steph.) Sukkharak. A. Portion, 2015

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

6b. Thysananthus convolutus var. laceratus (Steph.) , comb. nov.

Basionym: Thysananthus laceratus Stephani (1912a: 796) . Type: MALAYSIA. Sabah: “Brit. N Borneo, Ulu Moanat Labuh river ”, 1 September 1902, Elton s.n. (holotype G!); Icon. Steph. nr. 10190 .

Keel with appendages on one side where leaves and underleaves are free and opposite to adnate ones, always curved towards the stems. Underleaf apex strongly recurved. Perianth keels in upper 1/3 with numerous laciniate teeth, the teeth consisting of 4–8 cells, being 2–3 cells wide at base and ending in a row of 2–6 cells. Fig. 15 .

Distribution and ecology:— Borneo; without ecological information.

Representative specimens:—Malaysia. SARAWAK: Mt. Dulit, Richards 2357 (BM). Indonesia. KALIMANTAN: Nunukan, Meijer B4874 (NICH).

Taxonomic notes:— The distinguishing characters of this variety are (1) presence of an appendage on the keel, on the side where leaves and underleaves are free and opposite to the adnate ones (appendages always curved towards the stems), (2) strongly recurved underleaf apex, and (3) obovate perianths with 3–6 cells long teeth.

Figures

FIGURE 15. Thysananthus convolutus var. laceratus (Steph.) Sukkharak. A. Portion of shoot, ventral view. B. Leaves, ventral view. C. Underleaves, ventral view. D. Female bracts, ventral view: a = appendage. E. Female bracteole, ventral view. F. Perianth, dorsal view. G. Perianth, ventral view. H. Leaf apex. I. Margin cells of leaf lobe. J. Median cells of leaf lobe. K. Basal cells of leaf lobe. L. Leaf lobule apices. M. Leaf lobule base. N. Cross section of stem. (All from the lectotype).