Didymodon hegewaldiorum (Pottiaceae), a new species from the Tropical Andes

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1 Journal of Bryology (2008) 30: Didymodon hegewaldiorum (Pottiaceae), a new species from the Tropical Andes JUAN A. JIMÉNEZ and MARIA J. CANO Universidad de Murcia, Spain SUMMARY Didymodon hegewaldiorum J.A.Jiménez & M.J.Cano, is described as a new Neotropical species from dry puna of Peru and Bolivia. It differs most saliently from other species of Didymodon Hedw. in its stems with hyalodermis and without sclerodermis, ovate to ovate-lanceolate and appressed leaves when dry, bistratose leaf lamina, plane margins throughout, and a short and straight peristome. Drawings, LM and SEM photographs of the most important characters are given, and possible confusion with other taxa, such as Didymodon australasiae (Hook. & Grev.) R.H.Zander, D. fuscus (Müll Hal.) J.A.Jiménez & M.J.Cano, D. minusculus (R.S.Williams) R.H.Zander and D. rigidulus var. subulatus (Thér. & E.B.Bartram ex E.B.Bartram) R.H.Zander, is discussed. KEYWORDS: Bolivia, Didymodon, Peru, Pottiaceae, South America, taxonomy. INTRODUCTION In the 1970s, Eberhard and Pirkko Hegewald made a large collection of bryophytes from 16 departments in Peru (Hegewald & Hegewald, 1977, 1985). Of the about 3814 specimens collected, only a small proportion were determined. On the basis of these collections, they published the two cited works, where 167 species of mosses were recorded as new to Peru. This Peruvian collection together with the rest of the Hegewald s herbarium was acquired by the Missouri Botanical Garden in Despite that taxonomic and floristic research on the mosses of the Tropical Andes has increased in the last years, the knowledge of its moss flora is still relatively poor. The most recent checklist for Peru was provided by Menzel (1992), who reported a total of 889 species. According to Churchill, Griffin & Lewis (1995), the moss flora of Peru is the least known of the Andean countries. However, the number of mosses known from Peru is steadily increasing as specific groups in Peru are studied and additional collections are made. An example of this are the numerous papers published recently about different members of the family Pottiaceae (Cano, 2008; Cano & Gallego, 2008; Cano et al., 2008a,b; Gallego, Cano & Guerra, 2006; Jiménez, 2007; Jiménez & Cano, 2008). During a postdoctoral stay at MO focused on the taxonomic revision of the genus Didymodon for South America, the first author had the opportunity to study numerous specimens of Pottiaceae collected by the Hegewalds. Among them, several specimens labelled as Barbula sp. and Didymodon sp., and belonging to a small and distinctive species of Didymodon were found. Later, this species was also collected by us during field trips in Peru and Bolivia. We studied the types of the American taxa and compared these specimens with the relevant literature (Allen, 2002; Jiménez, 2006; Jiménez et al., 2005; Li, Crosby & He, 2001; Magill, 1981; Zander, 1993, 2007). A detailed studied of these specimens revealed that it did not match the concept of any of the species known in the genus, and consequently we here describe the new species D. hegewaldiorum. Didymodon hegewaldiorum J.A. Jiménez & M.J. Cano sp. nov. (Figs 1, 2) Caulidia erecta, centrali filo distincto atque hyalodermide praedita, sclerodermide autem destituta. Phyllidia exsiccatione adpressa, ovata vel ovato-lanceolata, dimidia superiore parte laminari bistrata et apice cucullato saepe obtusa, rubro-aurantiaca si addatur KOH; marginibus planis, dimidia superiore parte bistratis; mediis atque superioribus laminaribus cellulis rotundatis, quadratis vel hexagonalibus, papillosis; nervo, sectione transverse peracta, eurycystes monostratas manifestanti, apicem plerumque non attingenti raro percurrenti. Dioicus. Peristoma dentibus 32 praeditum, brevibus, rectis papillosisque. # British Bryological Society 2008 Received 13 January Revision accepted 11 March 2008 DOI: / X300589

2 122 J. A. JIMÉNEZ AND M. J. CANO Figure 1. Didymodon hegewaldiorum. (a) habit, dry; (b e) leaves; (f) leaf apex; (g) axillary hair; (h) upper lamina cells; (i) basal lamina cells; (j m) transverse sections of a leaf from basal to apical part; (n) transverse section of stem; (o) peristome. All from the holotype. Scale bars: (a) 1 mm; (b e) 20 mm; (f) 50 mm; (g and h) 20 mm; (i) 40 mm; (j m) 30 mm; (n) 25 mm; (o) 60 mm.

3 DIDYMODON HEGEWALDIORUM SP. NOV. FROM THE NEOTROPICS 123 Figure 2. Didymodon hegewaldiorum: (a) leaf; (b) dorsal surface of leaf apex; (c) ventral surface of leaf apex; (d) upper lamina cells. All from the holotype. Type: PERU. JUNÍN: Jauja, La Oroya, Laguna Mesapata bei Canchayllo, 28 April 1973, Hegewald & Hegewald 5385 (holotype: MO). Plants to 1.5 cm high, growing in dense turfs, red to brown-reddish, seldom brown-green. Stems erect, simple or branched, with hyalodermis, central strand differentiated, sclerodermis absent; axillary hairs filiform, 3 6 cells long, with one brown basal cell and hyaline upper ones. Rhizoidal tubers absent. Leaves appressed when dry, erect-patent to patent when moist, ovate or ovate-lanceolate, mm; lamina completely or irregularly bistratose in upper middle part of leaf, red-orange with KOH; apex obtuse, often cucullate; margins entire, plane, bistratose above mid-leaf. Costa mm wide at base, ending below apex, occasionally percurrent; ventral cells of costa in upper middle part of leaf quadrate or subquadrate, papillose; dorsal cells of costa in upper middle part of leaf quadrate or subquadrate, smooth or papillose; transverse section semicircular to elliptical; with 3 4 guide cells in one layer, 0 1 layer of ventral stereids, one layer of dorsal stereids, without hydroids, ventral surface cells slightly bulging, papillose, dorsal surface cells differentiated, smooth or papillose. Upper and middle lamina cells rounded, subquadrate or hexagonal, often transversely elongate near lower leaf margins, mm, with 1 2 low, simple or bifurcate papillae per cell, thick-walled; basal cells quadrate to rectangular, mm, not differentiated, smooth, evenly thick-walled. Gemmae absent. Dioicous. Perichaetia terminal; perichaetial leaves similar to vegetative leaves. Seta cm long, brownreddish, spirally twisted to left throughout. Capsule erect, ellipsoidal, mm, brown. Annulus persistent, composed of 1 2 rows of vesiculose cells. Peristome of 32 filiform teeth, papillose, straight, mm long, brown-yellowish. Operculum rostrate, mm long. Calyptra cucullate, smooth, 1.4 mm long. Spores mm in diameter, slightly papillose, brown-yellowish. Etymology: This moss is named to honor the collectors, Eberhard and Pirkko Hegewald. Non-type specimens examined. BOLIVIA. ORURO: pr. Lequepalca, Cano et al (MUB). PERU. APURÍMAC: Andahuaylas, Hegewald & Hegewald 5788 (MO). CUZCO: Canchis, Cerro Chuaña, Hegewald & Hegewald 8621 (MO). JUNÍN: Abra de la Viuda, Cano & Guerra 2039b (MUB). Jauja, La Oroya, Hegewald & Hegewald 5341a (MO). Jauja, Südlich Canchayllo, Hegewald & Hegewald 5849 (MO). HABITAT AND DISTRIBUTION Didymodon hegewaldiorum occurs in dry Puna of Peru and Bolivia, on soil and rocks between 3750 and 4175 m. This new moss seems to be an endemic of the Central Andes although it is probably widely distributed in the Tropical Andes. Owing to its small size and similar appearance to other species of Didymodon, especially D. australasiae

4 124 J. A. JIMÉNEZ AND M. J. CANO (Hook. & Grev.) R.H.Zander, with which it can grow, it may easily be confused or even completely overlooked. DIFFERENTIATION Didymodon hegewaldiorum is characterized by its stems with hyalodermis and without sclerodermis, ovate to ovatelanceolate leaves that are appressed when dry, a bistratose leaf lamina above mid-leaf, plane margins throughout, a costa that usually ends below the apex, and a short and straight peristome of 32 teeth. Didymodon hegewaldiorum is closely related to D. australasiae, sharing such distinctive characteristics as the shape of the leaves with a cucullate apex, plane and bistratose leaf margins above midleaf, and shape and size of the leaf lamina cells. However, D. australasiae has leaves crisped, twisted, or incurved when dry and basal lamina cells differentiated, hyaline, with very thin walls, while in the new species the leaves are appressed when dry, and the basal lamina cells are not differentiated and thick-walled. Didymodon rigidulus var. subulatus (Thér. & E.B.Bartram ex E.B.Bartram) R.H.Zander, a species known from southern United States and Mexico (Zander, 2007) as well as Bolivia and Peru (Churchill & Fuentes, 2005; Churchill, Griffin & Muñoz, 2000) resembles D. hegewaldiorum in the bistratose lamina. It differs from D. hegewaldiorum in having its costa excurrent in a subula and smooth leaf lamina cells. The other two South American species with bistratose lamina that may be confused with the new species are Didymodon minusculus (R.S.Williams) R.H.Zander and D. fuscus (Müll Hal.) J.A.Jiménez & M.J.Cano. The former is a Peruvian endemic that additionally resembles D. hegewaldiorum in several characteristics, such as the small size of the plants, orientation of dry leaves, leaf shape, and the papillosity of the lamina cells. Nevertheless, D. minusculus can be separated from D. hegewaldiorum by its recurved leaf margins, the presence of a well developed sclerodermis, the absence of a stem hyalodermis, and a costa without ventral stereids and guide cells in 1 2 layers. Didymodon fuscus, is endemic to Argentina and Chile (Jiménez & Cano, 2006), and is similar to D. hegewaldiorum in the colour of the plants and lamina with KOH, shape and size of the leaf cells, and in having a bistratose leaf lamina. This species is easily distinguished by its acute leaf apices, recurved leaf margins, smooth lamina cells, and a costa without ventral stereids and guide cells in three layers. ACKNOWLEDGEMENTS The first author is grateful to Richard Zander and Bruce Allen for help during his stay at the Missouri Botanical Garden. We thank several institutions and persons for assistance during our field studies: in Bolivia, Herbario Nacional de La Paz; and Peru, Universidad de San Marcos of Lima, (A. Cano). Thanks also to Manuel Laínz for the Latin diagnosis and Juan Guerra for uncompromising support. Financial support was provided by the Spanish Ministerio de Educación y Ciencia (Projects CGL , CGL /BOS co-financied by FEDER), Fundación SÉNECA (Project 02979/PI/05), and the Juan de la Cierva Program. TAXONOMIC ADDITIONS AND CHANGES: Didymodon hegewaldiorum J.A.Jiménez & M.J.Cano, sp. nov. REFERENCES Allen B Moss flora of Central America, Part 2. Encalyptaceae- Orthotrichaceae. Monographs in Systematic Botany from the Missouri Botanical Garden 90: Cano MJ Taxonomic revision of Hennediella Paris (Pottiaceae, Bryophyta). Bryophytorum Bibliotheca, in press. Cano MJ, Gallego MT The genus Tortula (Pottiaceae, Bryophyta) in South America. Botanical Journal of the Linnean Society 156: Cano MJ, Gallego MT, Jiménez JA, Guerra J. 2008a. Aloina obliquifolia (Pottiaceae, Bryophyta) new to South America, and new reports of Aloina in the Neotropics. Cryptogamie, Bryologie 29: Cano MJ, Jiménez JA, Churchill SP, Guerra J. 2008b. New records of Pottiaceae (Bryophyta) for South America. Cryptogamie, Bryologie 29: Churchill SP, Fuentes AC Additions, combinations and synonyms for the Bolivian moss flora. Tropical Bryology 26: Churchill SP, Griffin III D, Lewis M Moss diversity of the Tropical Andes. In: Biodiversity and Conservation of Neotropical Montane Forests. Bronx, NY: New York Botanical Garden, pp Churchill SP, Griffin III D, Muñoz J A checklist of the mosses of the tropical Andean countries. Ruizia 17: Gallego MT, Cano MJ, Guerra J Syntrichia ammonsiana (Pottiaceae), new to South America. The Bryologist 109: Hegewald E, Hegewald P Eine Moossammlung aus Peru I. Nova Hedwigia 28: Hegewald E, Hegewald P Eine Moossammlung aus Peru III. Nova Hedwigia 41: Jiménez JA Taxonomic revision of the genus Didymodon Hedw. (Pottiaceae, Bryophyta) in Europe, North Africa and Southwest and Central Asia. Journal of the Hattori Botanical Laboratory 100: Jiménez JA Bryoerythophyllum berthoanus comb. nov. and B. sharpii (Bryophyta, Pottiaceae) in South America. Journal of Bryology 29: Jiménez JA, Cano MJ Two new combinations in Didymodon (Pottiaceae) from South America. The Bryologist 109: Jiménez JA, Cano MJ A new species of Didymodon Hedw. (Pottiaceae, Bryophyta) from Peru. Botanical Journal of the Linnean Society 156: Jiménez JA, Ros RM, Cano MJ, Guerra J A new evaluation of the genus Trichostomopsis (Pottiaceae, Bryophyta). Botanical Journal of the Linnean Society 147: Li X-J, Crosby MR, He S Moss flora of China. English version. Vol. 2. Fissidentaceae Ptychomitriaceae. Beijing/St Louis, MO: Science Press/Missouri Botanical Garden Press. Magill RE Flora of Southern Africa. Bryophyta. Part 1. Mosses. Fasc. 1. Sphagnaceae Grimmiaceae. Pretoria: Botanical Research Institute, Department of Agriculture and Fisheries. Menzel M Preliminary checklist of the mosses of Peru (Studies on Peruvian Bryophytes IV). Journal of the Hattori Botanical Laboratory 71:

5 DIDYMODON HEGEWALDIORUM SP. NOV. FROM THE NEOTROPICS 125 Zander RH Genera of the Pottiaceae: mosses of harsh environments. Bulletin of the Buffalo Society of Natural Sciences 32: Zander RH Didymodon. In: Bryophyte Flora of North America. North of Mexico, Vol. 27. Bryophyta. Part 1. New York: Oxford University Press, pp JUAN A. JIMÉNEZ and MARíA J. CANO, Departamento de Biología Vegetal (Botánica), Facultad de Biología, Universidad de Murcia, Campus de Espinardo Murcia, Spain. jajimene@um.es