A new species of Taxithelium (Sematophyllaceae) from Seram, Indonesia PAULO E. A. S. CAˆMARA CAPES Fellow, Missouri Botanical Garden, P.O. Box 299, Saint Louis, MO 631160299, U.S.A.; Biology Department, University of Missouri at Saint Louis, One University Boulevard, Saint Louis, MO 63121 U.S.A. Departamento de Botaˆnica, Universidade de Brası´lia, UnB. Campus Darcy Ribeiro, Caixa Postal 04457, Brası´lia, DF, 70910-970, Brazil e-mail:
[email protected] ABSTRACT. During a revision of the genus Taxithelium, a new species was found from the island of Seram, Indonesia. The presence of collenchymatous exothecial cells, a resemblance to Radulina, but being a much smaller plant, lacking any papillae on the seta and having the alar cells much less developed and neither inflated nor colored associate it with Taxithelium. Multivartiate analyses support its infrageneric distinctiveness. KEYWORDS. Taxithelium, Seram, Indonesia, Sematophyllaceae.
¤ Taxithelium Mitt., a genus of pleurocarpous mosses (sensu La Farge-England 1996) traditionally associated with Sematophyllaceae, is probably one of the most widespread moss genera in the tropics, mostly between 30uN and 20uS, but with most species occurring in Southeast Asia, especially the Malesian region (Damanhuri & Longton 1996; Ramsay et al. 2002). The main character that defines Taxithelium is the presence of multiple papillae disposed in series on the lumina of leaf cells (hence, Tax- ‘‘taso’’ 5 arranged and thelion 5 nipple), a rare character in the Hypnales that has been described only twice in the Sematophyllaceae (in Taxithelium and in Radulina). Other characters that are useful in recognizing the genus are the usually complanate branches with leaves having an alar region usually not nearly as well developed as in most Sematophyllaceae. Taxithelium has not been revised for Southeast Asia and there is no worldwide treatment for the
¤
¤ genus but ongoing studies suggested that the genus is monophyletic and originated in Southeast Asia. During a taxonomic revision of the genus (Caˆmara, unpublished), two subgenera were recognized based on morphological and molecular data. Within one of the groups only two species are reported to the New World and ten to the Old World plus one quite distinct plant that has been found to be a new species from Seram, Indonesia.
MORPHOMETRIC ANALYSIS Species recognition is not based here solely on morphometric data, but also by the presence of unique discrete morphological characters (see notes below), morphometric data is presented here as further evidence of morphological distinctiveness. Methods. In order to quantitatively compare the distinctiveness of the newly found taxon, I sampled 100 herbarium specimens (including types) from across the extent of geographic and morphological variation encompassed by all species (except the New
The Bryologist 112(3), pp. 589–592 Copyright E2009 by The American Bryological and Lichenological Society, Inc.
0007-2745/09/$0.55/0
590
THE BRYOLOGIST
112(3): 2009
Figure 1. Scatter plot. Dashed line represent specimens of T. damanhurianum. All other taxa are the remaining Taxithelium species from the Old World.
World ones) plus the new species. Measurements were taken and analyses were performed using SPSS (version 16.0 for Macintosh). Eleven morphological quantitative characters were selected for study: 1) leaf length, 2) leaf width, 3) leaf cell length, 4) leaf cell width, 5) perichaetial leaf length, 6) perichaetial leaf width, 7) perichaetial leaf cell length, 8) perichaetial leaf cell width, 9) seta length, 10) rhizoid length and 11) spore diameter. Results. A total of 72.6% of the variation was explained by three components. Component 1 explains 39.1% of the variation, and mostly reflects variation in perichaetial leaf length, seta length and perichaetial leaf cell width. Component 2 represents 19.2% of the variation and reflects variation mostly in leaf width, perichaeteial leaf cell length and leaf cell length. Component 3 represents 14.2% of the
variation and reflects variation mostly on leaf cell length, leaf length and seta length. The new species (number 10) is recognized as distinct in the analyses (Fig. 1).
THE NEW SPECIES Taxithelium damanhurianum P. S. Caˆmara sp. nov. Figs. 2, 3 A Taxithelium muscicola in planta minore, cellulis exothecii collenchymatosis differt. TYPE: INDONESIA. SERAM: Manusela National Park, Sawai, Akiyama C-9329 (holotype HYO!; isotypes NY!, L!). Description. Plants small, forming goldenyellow mats. Stems creeping, branches longascending. Rhizoids evenly distributed along the
Caˆmara: A new Indonesian Taxithelium
591
Figure 2. Taxithelium damanhurianum. A. Alar cells. B. Branch leaf. C. Leaf margin cells. D. Perichaetial alar region. E. Perichaetial leaf. B and E scale a; A, C, D, scale b. Drawn from Akiyama C-9329 (NY).
Figure 3. Collenchymatous exothecial cells in T. damanhurianum (4003).
stem. Stem and branch leaves similar, erectspreading, concave, 0.52–0.88 3 0.10–0.20 mm, linear-lanceolate, long acuminate; margins serrulate; costae absent; laminal cells linear, 70–74 3 ca. 2 mm, seriately papillose over the lumina, thick-walled, basal cells sometimes smooth; alar cells well differentiated, consisting of 1–2 rows, 1 of inflated, vesiculose and concolorous cells, supra alar cells not inflated. Asexual propagula absent. Autoicous. Perigonia lateral; paraphyses present; antheridia 3–5; leaves lanceolate to oblong, concave; costae absent; laminal cells fusiform, lax, usually pluripapillose; alar cells not differentiated. Perichaetia lateral; paraphyses present; archegonia 3–5; leaves 0.4–0.6 3 0.14– 0.25 mm, ovate, narrowly acuminate; margins entire; costae absent; laminal cells fusiform at midleaf, quadrate at base, 40–46 3 ca. 2 mm, thick-walled, smooth at base, pluripapillose at apex; alar cells well developed. Setae elongate, slender, smooth, 7–10 mm long. Capsules inclined, asymmetric, ovoid, constricted below mouth when deoperculate, 0.5– 0.8 mm long; exothecial cells quadrate, strongly collenchymatous; annulus not differentiated; operculum not seen; peristome double, hypnoid,
exostome teeth narrowly triangular, with ziz-zag median line, cross-striolate below, papillose above, trabeculate at back; endostome with a high basal membrane, segments keeled, papillose, broad, perforate, as long as the teeth; cilia single, narrow, nodulose. Spores spherical, smooth, 16–20 mm in diameter. Calyptrae not seen. Etymology. The epithet damanhurianum refers to Prof. Ahmad Damanhuri Mohamed, the first to study Taxithelium worldwide and a great collector in Malaysia. Notes. A remarkable feature in this species is the presence of strongly collenchymatous exothecial cells (Fig. 3), which have not previously been reported in the genus (even though slightly collenchymatous cells are present in some New World species of Taxithelium). This character, along the relatively well-developed alar cells, resembles Radulina, but T. damanhurianum is a much smaller plant, also T. damanhurianum lacks any papillae on the seta (Radulina has distally papillose setae), and the alar cells are much less developed and neither inflated nor colored like the ones found in Radulina. Unfortunately, only a few collections (only 3
592
THE BRYOLOGIST
112(3): 2009
All specimens studied here were labeled and been previously reported as Taxithelium levieri (Akiyama 1993). This is probably due to the fact that both species are usually found associated together in the same packet. The new species is restricted to the island of Seram, Indonesia (Fig. 4), where it is epiphyllous and occurs at 100–650 m. Additional specimens examined. INDONESIA. SERAM: Manusela National Park, Akiyama C-9409, C9923 (HYO!, NY!, L!).
Figure 4. Distribution map for T. damanhurianum.
vouchers out of 6000 studied) of this plant are known and it was impossible to obtain DNA from the specimens. As this species would fit into Taxithelium, and to avoid describing a new genus, I consider this odd plant to be a new species of Taxithelium, at least until further evidence is gathered. As new collections and fresh material become available, a molecular analysis may solve this question. Among the species from Southeast Asia, the one that most resembles T. damanhurianum is T. muscicola (Broth.) B.C. Tan, H.P. Ramsay & W.B. Schofield, but the former is much smaller and narrower. The spores are also different, in T. muscicola they are finely papillose and smaller, and only 12–16 mm in diameter while in T. damanhurianum they are smooth and 16–20 mm in diameter. Although the plants of T. damanhurianum are smaller it has larger spores. Also, as said, the presence of collenchymatous exothecial cells is also a unique feature in T. damanhurianum From all the remaining species, besides the presence of collenchymatous exothecial cells T. damanhurianum can also be distinguished by the presence of relatively well-developed alar cells and smaller perichaetial leaves.
ACKNOWLEDGMENTS This study was funded by the Missouri Botanical Garden, CAPES (Brazilian government), and the Stephen M. Doyle Memorial Fellowship. I thank Bob Magill, Bruce Allen, Steve Churchill, Bill Buck, Peter Stevens, Ben Tan and Toby Kellogg for helping with the manuscript. I am very thankful to Dr. Akiyama for providing loans and helpful comments. Michael Stech is acknowledged for helping with the loans in Leiden.
LITERATURE CITED Akiyama, H. 1993. Taxonomic studies of mosses of Seram and Ambon (Mollucas, East Malesia) collected by IndonesiaJapanese botanical expedition, VII. Lembophyllaceae, Splachnaceae, Myuriaceae, Neckeraceae, Brachytheciaceae, Amblystegiaceae and Sematophyllaceae, with additions to previous reports on Dicranaceae and Pterobryaceae. Journal of the Faculty of Science, University of Tokyo, Botany III, 15(3): 219–254. Damanhuri, A. & R. E. Longton. 1996. Towards a revision of the moss genus Taxithelium (Sematophyllaceae). Anales del Instituto de Biologı´a, Universidad Auto´noma de Me´xico, Serie Bota´nica 67: 35–58. La Farge-England, C. 1996. Growth form, branching pattern, and perichaetial position in mosses: cladocarpy and pleurocarpy redefined. The Bryologist 99: 170–186. Ramsay, H. P., W. B. Schofield & B. C. Tan. 2002. The genus Taxithelium (Bryopsida, Sematophyllaceae) in Australia. Australian Systematic Botany 15: 583–596.
ms. received May 30, 2008; accepted February 26, 2009.
