J Hattori Bot. Lab. No. 83 : 251-255 (Nov. 1997)

LEIOMELA (, MUSCI), A NEW GENUS FOR ARGENTINA

CELINA M. MATTERl I

ABSTRACT. Leiomela (Bartramiaceae), is a new genus for Argentinian flora. Leiomela bar­ tramioides (Hook.) Par. is recorded for the first time from the Misiones Province (NE Argentina). Complete description and illustration of the species are provided.

While studying a small collection of from the Misiones Province, in northeast­ ern Argentina, an epiphytic specimen attracted my attention because of its perigonial leaves that bore a long capillary hair. It proved to be the widespread species Leiomela bar­ tramioides (Hook.) Par. Being a taxon not yet recorded for Southern South America, it is appropriate to give some information on this peculiar genus. Leiomela is a small genus of the Bartramiaceae with almost a dozen species of pantropical distribution, from Mexico, the Caribbean Islands, Central and South America to central Africa, with one species recorded from western Java. The genus has not been re­ vised worldwide and it possibly includes several synonyms, especially species in the neo­ tropical moss flora. Recently Griffin and Buck (1989) suggested a subdivision of the family Bartramiaceae into three subfamilies. Following their scheme the presently known genera of Bartrami­ aceae from Chile and Argentina are and Leiomela within the Bartramioideae, the sole genus in the Conostomoideae, and and in the Breutelioideae. Bartramidula cygnea Mont., the only regional representative of the genus (Matteri, 1984) was transferred to Philonotis as P cygnea (Mont.) Griffin & Buck. In the Bartramioideae, Leiomela is easily separable from Bartramia primarily by sporophytic characters: the immersed capsules, the reticulate plus the gymnosto­ mous condition of some species. Although it is generally thought that Bartramia has a hyalodermis in the stem, some species such as B. halleriana and B. stricta lack it as is the case in leiomela. However, the extraordinary length of perigonial and perichaetial leaves, being 3 to 6 times longer than stem leaves, together with the immersed capsules are diag­ nostic for the genus. Moreover, its ornamentation is unique within the family (Grif­ fin, 1981 ). leiomela bartramioides was first described in the genus leucodon by Hooker (1837) from material collected by W. Jameson in Ecuador. It was subsequently redescribed several times under different generic and specific names until Paris, in the second edition of his Index Bryologicus (1905), arrived at its current generic disposition. The species occurs in the neotropics from Mexico to subtropical South America (Griffin & Hegewald, 1986; Her­ mann, 1976; Menzel, 1986; Yano, 1981 ), and central Africa and Reunion Island (Bizot,

1 Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Av. A. Gallardo 470, 1405 Buenos Aires, Argentina. 252 1. Hattori Bot. Lab. No. 83 I 9 9 7

1968; De Sloover, 1975). Now it is reported from northeastem Argentina, at the southeast­ em comer of the Misiones Province in the tree-fem district of Martinez-Crovetto (1963). Its distribution pattern is described as a southern amphiatlantic

Leiomela bartramioides (Hook.) Par. Figs. I, 2 Ind. Bryol. ed. 2, 3: 132, 1905. Leucodon bartramioides Hook., Icon. Pl. rar., 1: 71, 1837. medium sized, stems 2-3 cm high, single or with a few subfloral branches, in loose, light-green tufts; medium and lower parts of stem with felt-like tomentum formed by densely papillose rhizoids; axillary hairs filiform, 6-12 cells long; stem cross section an­ gled, with 1-2 rows of thick-walled epidermal cells, enlarged thin-walled cortical cells and a small central strand. Stem leaves crowded, erect-spreading to tlexuose, linear subulate, with a slightly differentiated base, 4-5 mm longX0.3-0.4 mm wide at base; margins mostly plane, slightly revolute at middle part, coarsely serrulate almost to base; costa excurrent, 50 µm wide at base, papillose and prominent at back; median leaf cells oblong, 9- 12 X 5- 6 µm, coarsely prorulose, prorulae single or bifid, upper basal cells longer and prorulose, 35- 50X6-7 µm, lower basal cells smooth. Dioicous. Perichaetia and perigonia terminal, secondarily lateralized by develop­ ment of 1-2 subfloral branches; perichaetial leaves with long setaceous lamina, 10-15 mm long, from a short oblong sheathing base to 1 mm long; margins strongly toothed through­ out, upper teeth inflated; costa excurrent; upper lamina! cells elongate, slightly prorulose, lower lamina} cells and upper basal cells shorter, densely prorulose; perigonial leaves simi­ lar to perichaetial but much longer, (I 0)21 (30) mm and with an oval and very concave base encompassing antheridia and many filiform paraphyses. Seta less than I mm long, capsule hidden amongst perichaetial leaves, immersed, erect, smooth, oval-oblong, 2- 2.5 X 1.5 mm, operculum flat with a small apiculus in the middle; peristome double, inserted well below the rim, exostome teeth widely separated, 220-240 µm long, smooth to rugose, irregularly perforated, occasionally paired at apex; endostome rudimentary. Spores subspherical, retic­ ulate, light brown, (20)26(32) µm in diam., under SEM lumina of reticulum are of different shapes and sizes with verruca-like processes widely scattered over the reticulum.

The specimen was found with few sporophytes, between 0-300 m, growing on bark of trees, intermixed with Hymenodon aeruginosum (Hook. f. & Wils.) C. Muell., another small epiphytic moss. Leiomela bartramioides appears to be an uncommon species in the region and it is not cited from the neighboring Brazilian lands of Santa Catarina and Rio Grande do Sul. The Argentinian locality seems to be so far the southernmost record of the species in South America. Specimens examined. ARGENTINA. Prov. Misiones. Depto. Gurarani. Predio Guarani, 26°54- 59'8, 54°12- 18'W, Schinini et al. (CTES 28815, NY). PERU . Prov. Urubamba, Depto. Cuzco, Machu Picchu, Aguas Calientes, P. & E. Hegewald 8669 (U). ECUADOR. Prov. Carchi, Road Tulcan-Maldona- C. M. MATTERJ: Leiomela, a new genus for Argentina 253

SOµm F

Fig. l. Leiome/a bartramioides. A, . B, part of stem cross-section. C, perigonial leaf. D, stem leaves. E, median lamina! cells. F, apex of stem leaf. G, median cross section of stem leaf. From CTES 28815. 254 J. Hattori Bot. Lab. No. 83 I 9 9 7

Fig. 2. Leiomela bartramioides. A, B, spore. C, D, teeth of exostome. Scanning elec­ tron micrographs from CTES 28815 . C. M . MATTERJ : Leiomela, a new genus for Argentina 255 do, km 30, 048'N, 77°56'W. Frahm et al. 295 (BA).

ACKNOWLEDGEMENTS I wish to thank J.-P. Frahm for help in the recognition of the genus and W.R. Buck for his kind advise and correction of the first version of this paper. Thanks are also due to the Curator of the herbarium CTES for allowing me to study the moss collections.

LITERATURE CITED Bartram, E. B. 1949. Mosses of Guatemala. Fieldiana, Bot. 25 : 1-442. Bizot, M. 1968. Mousses recoltees par Mr. Gillis Een dans Jes Iles Maurice et de La Reunion. Svensk Bot. Tidskrif62(3): 471-481. De Sloover, J. L. 1975. Note de bryologie africaine V. - Anaco/ia, Leiomela, Cyathophorel/a. Bull. Jard. Bot. Nat. Belg. 45 : 313- 32 1. Griffin, III, D. 1981. Spore ornamentation in Leiomela (Musci, Bartramiaceae). Cryptog., Bryol. Lichenol., 2, I: 101 - 106. Griffin, III, D. & E. Hegewald, 1986. A collection of Bartramiaceae from Peru. J. Hattori Bot. Lab. 60: 159- 165. Griffin, III, D. & W. R. Buck, 1989. Taxonomic and phylogenetic studies on the Bartramiaceae. Bry- ologist 92(3): 368- 380. Hermann, F. J. 1976. Recopilaci6n de los musgos de Bolivia. Bryologist 79: 125- 171. Hooker, W. J. 1837. Icones plantarum rariorum, I: tab. 71 , fig. 1- 8. Martinez-Crovetto, R. 1963. Esquema fitogeografico de la Provincia de Misiones (Republica Argenti­ na). Bonplandia 1(3): 171 - 223. Matteri, C. M. 1984. Sinopsis de !as especies Andino-patag6nicas, Antarticas y Subantarticas de los generos Bartramia, Bartramidula y Conostomum (Bartramiaceae, Musci). Darwiniana 25(1-4): 143- 162. Menzel, M. 1986. Studies on Peruvian Bryophytes I. A recent collection of mosses from the forests and some general distributional notes. Willdenowia 16: 259- 268. Menzel, M. & W. Schultze-Motel, 1987. Studies on Peruvian bryophytes III. Analysis of the distribu­ tion patterns ofMusci. Mem. New York Bot. Gard. 45 : 371 - 387. Paris, E. G. 1905. Index Bryologicus, ed. 2, 3: 1-400. Sharp, A. J., H. Crum & P. M. Eckel (eds.). 1994. The moss flora of Mexico. Mem. New York Bot. Gard. 69: 1- 1113. Yano, 0 . 1981 . A checklist of Brazilian mosses. J. Hattori Bot. Lab. 50: 279-456.