The Bryologist 97(4), 1994, pp. 402-408 Copyright ? 1994 by the American Bryological and Lichenological Society, Inc. Orthotrichum macrocephalum sp. nov., a New Moss of Section Diaphana from the Iberian Peninsula FRANCISCO LARA, RICARDO GARILLETI, AND VICENTE MAZIMPAKA Departamentode Biologia (Botanica),Facultadde Ciencias, UniversidadAutonoma de Madrid,Canto Blanco, E-28049 Madrid,Spain Abstract. A new Orthotrichum is describedfrom the Mediterranean zone of the Iberian Peninsula. The new species is included in section Diaphana Vent. in Husn. subgenus Pulchella (Schimp.) Vitt. It is characterized by lingulate, carinate leaves with rounded apices, immersed capsules with stomates almost completely covered by protruding subsidiary cells, and by characteristic ornamentation of the peristome. Drawings and scanning electron micrographs of several gametophytic and sporophytic characters are provided. The ecology and distribution, as well as differences from and relationships with similar Orthotrichum species, are discussed. MACROCEPHALUM ORTHOTRICHUM Lara, Garilleti & (FIG. 1-20) Mazimpaka sp. nov. Planta parva, compacta, cum filidiis erecto-adpressis apicis rotundativel obtusi, sine cellulibus elongatis hyalinisque. Capsulaimmersaad emergentem;exostoma 8 segmentis bigeminatis,in sicco recurvatis,in basi papillosis, in dimidio superiorepaginaqueintema tota striatis; endostoma 8 processibusirregulariterbiseriatisin pagina interna papillosis. Stomata cryptopora,generalitercum cellulibussubsidiariisevolutissimis. TYPE:SPAIN. GUADALAJARA. Oak wood near Torija, 30TVL9407,900 m altitude.Epiphyteon Quercusfaginea Lam., Albertos,Garilleti& Lara, 8 January 1993 (holotype: MA, Musci 12921; isotype:BCB). Plants small, to 0.6 cm tall, scattered or in cushions up to 0.5 cm diam., dark-green, simple or only little branched. Leaves erect-appressed to erectopatent when dry, spreading when moist, 1.9-2.8 mm long; lingulate or lanceolate-lingulate, concave and carinate, young leaves cochleariform, scarcely papillose; median and lower leaves shorter and blunter than upper ones; apex rounded to obtuse, without hyaline apiculus although sometimes with a small mucro formed by a rounded nonhyaline cell; costa strong, ending shortly and clearly below apex (80-150 ,um);margins entire, plane or revolute near base, revolute in medium third of leaves, plane near apex, where they become irregularly crenulate, sometimes erose and hyaline in older leaves; basal cells elongate, rectangular to irregularly polygonal, with thin nonnodulose walls, 25-45 x 11-17 ,tm, shorter toward margin and costa, smooth and hyaline or with small conic or hemispheric blunt papillae; midleaf cells firm, rounded to hexagonal, sometimes ellipsoid, 9-13 x 9-18 itm, moderately thick-walled, with 1-5(-7) low blunt papillae; upper leaf cells, where leaf becomes plane, rounded and ellipsoid, 9-12 x 14-19 ,um, smooth, very thick- walled. Septate cylindrical to filamentous brown gemmae occasional on both sides of leaves, sometimes abundant. Gonioautoicous, with antheridia close to base of stems. Sporophytes immersed or shortly emergent. Seta short, 0.35-0.45 mm; vaginula naked. Capsules oblong-cylindric or oblong, (1.3-)1.5-2.2 mm, with 8 deep furrows almost as long as capsule, moderately constricted in middle when dry, nonconstricted when moist, truncate at base and sharply contracted at setae when perfectly moist; striae formed by 5-6 rows of colored exothecial cells, only slightly differentiated near mouth; stomata cryptopore, usually completely covered by protruding well-differentiated subsidiary cells, sometimes only half covered, present in upper half of capsule, some of them near mouth, between striae. Peristome double; exostome of 8 pairs of teeth, orange, reflexed when dry, on outside densely papillose below, upward alternating individual papillae with alignment of papillae tending to be confluent, finally forming longitudinal striae near apex, with remains of cell walls strongly marked; on inside striate along teeth, with anastomosed papillae forming prominent crests; endostome with 8 keeled segments incompletely and irregularly biseriate or exceptionally uniseriate, clearly papillose on inside (sometimes with anastomosed papillae), smooth on outside, (with papillose appearance in the optical microscope), with tuberculate aspect due to thickened cell wall remnants; segments connected by a basal membrane ornamented with papillae similar to those of segments; without prostome. Operculum mammillate, scarcely convex. Calyptra cupulate, with dark beak, naked, slightly plicate, without papillae. Spores papillose-rugose, 15-20 Atm. Representative specimens studied- SPAIN. ALBACETE. Ri6par, junto a la pista del Molino de la Celada, 0007-2745/94/402-408$0.85/0 LARA ET AL.: ORTHOTRICHUMMACROCEPHALUM SP. NOV. 1994] le 1'1 403 2 [1 1 3 it( I nmm 4 z 4 I 6 7 I/ N (2AI' oO FIGURES1-7. Orthotrichum macrocephalum. - 1. Wet mature capsule, with operculum. - 2. The same capsule, dry. - 3. Wet mature capsules, after spore release. - 4. The same capsules, dry. - 5. Calyptra. - 6. Habit of two well-developed specimens, the left one with sporophytes. - 7. Young cushion. All from type. 30SWH5659, Albertos et al. (MA,Musci 12924); Yeste, ca. Tus, junto a la carretera, 30SWH4950, Albertos et al. (MA, Musci 12923). CIUDADREAL.Retuerta de Bullaque, carretera de Retuerta de Bullaque a Los Yebenes, rio Milagros, 30SUJ9469, Lara & Vergara (MA, Musci 12928). CUENCA.Cuenca, casco antiguo, 30TWK73, Jorquera & Lara (MA,Musci 12922, separated from MA,Musci 7522). GRANADA.Granada, jardines del Generalife, 30SVG4815, Lara (authors' herbarium). GuADALAJARA. Barriopedro, cerro de Valdelagua, 30TWL 1915, Albertos et al. (MA,Musci 12926). Torija, quejigal del valle de Torija, 30TVL9407, Albertos et al. (MA, Musci 12925), Garilleti & Lara (MA, Musci 12927). MADRID, El Escorial, bosque de La Herreria, 30TVK0292, Boheda & L6pez (separated from MA, Musci 9462). Orthotrichum macrocephalum is an epiphyte always growing with other small xerophilous mosses THE BRYOLOGIST 404 [VOL. 97 12 10 9 ?\ e A /*-^ o^ /^\ c?,-?0 r"b ^? FIGURES8-12. Orthotrichummacrocephalum.- 8. Leaves. - 9. Cross sectionsof leaves at differentlevels. - 10. Leaf cells of apex, middle, and base of leaves. - 11. Cross section at midleaf showingthe papillae. - 12. Gemmae. All from type. such as 0. pumilum Sw., 0. diaphanum Brid., 0. obtusifolium Brid., 0. acuminatum Philib., and Tortula laevipila (Brid.) Schwaegr. Its small size and the great superficial similarity with some of these- especially with 0. pumilum and 0. obtusifoliummake field identification difficult. This may be one of the reasons why it has been overlooked until now. Such circumstances interfered with the study of its 1994] LARA ET AL.: ORTHOTRICHUM MACROCEPHALUM SP. NOV. 405 FIGURES13-14. Orthotrichum macrocephalum. - 13. Young individual, showing its typical compact habit. - 14. Old capsule mouth; the exostome remains well preserved but the endostome is lost in this specimen. All from type. distribution, which was possible only after its ecological affinities had been established. The first samples, scarce and with few sporophytes, were found near El Escorial (Madrid) in a mixed wood of Fraxinus angustifolia Vahl and Quercus pyrenaica Willd. where, in spite of intensive sampling, it was found exclusively on the former (Lara 1993). Afterwards, a study of the epiphytic bryophytes in a Quercusfaginea Lam. wood near Torija (Guadalajara) supplied better specimens of the new moss. The occurrence of O. macrocephalum on Fraxinus angustifolia and Quercusfaginea, but never on Quercus pyrenaica, suggested a low tolerance to bark acidity. So, further prospecting was carried out over the central zone of the Iberian Peninsula, focusing our attention on Fraxinus angustifolia, Quercus faginea, and Quercus ilex L. woods. The results were not as good as expected. Only scarce populations, mostly without sporophytes, were found in a few localities. However, occurrence of the moss on planted Ulmus in the city of Cuenca, as well as on trees from areas subjected to human activities, indicated it could be nitrophilic. Up till now 0. macrocephalum has been found in several localities in the southern part of Spain (Fig. 21), always in anthropic environments, from 700 to 1,000 m a.s.l., on slightly acid bark (Quercus faginea Lam., Fraxinus angustifolia Vahl, Ulmus minor L., U. pumila L., Yucca sp., and Citrus au- rantium L.). The available data lead to the conclusion that it is a xerophilous and nitrophilous moss living in relatively humid areas, but subject to severe summer dryness. Its area in the Mediterranean zone of the Iberian Peninsula is probably much larger than is currently known. Further prospecting in anthropic environments of the most thermic and humid zones of the Spanish northeastern coast, Andalusia, southern Portugal, and northern Africa, may be essential to complete our knowledge of the ecology and distribution of the new moss. Section Diaphana Vent. in Husn. subgenus Pulchella (Schimp.) Vitt, in which 0. macrocephalum is included (subdivision following Lewinsky 1993), is a complex group that comprises 33 taxa. Orthotrichum macrocephalum shows sporophytic similarities with 0. pumilum Sw., such as the capsule form, with a short neck sharply contracted to the seta; however, the separation of the two taxa is not problematic: 0. macrocephalum has stomata almost covered by protruding subsidiary cells, larger urn, endostome with biseriate, tuberculate and papillose segments, exostome with a characteristic dense ornamentation, and with prominent, papillose striae and crests (Fig. 15-20). Moreover, the typical rounded leaf apex of the new moss, without hyaline apical cells, besides being a good macroscopic character for its recognition, separates the two species conclusively. Other small Orthotrichum species belonging to THE BRYOLOGIST 406 16o_ 2 :- [VOL.97 2 < _3 J s t v:'0\ ^wI 5 .)*> >- i 1f p-~i'<fo^a.-, .,.. '9~J1QI FIGURES15-20. Orthotrichum macrocephalum. - 15. Mouth of a semimature capsule in partial view with its operculum removed to show outside of exostome. - 16. External view of medium cells of exostome teeth. - 17. Internal view of basal cells of exostome teeth; papillae are anastomosed, forming dense longitudinal crests. - 18. Detail of inside of apical cells of exostome teeth; papillae are anastomosed, forming lax crests in all directions. - 19. Involute endostome segment; the outside is keeled and smooth, the inside is densely papillose. - 20. Detail of the inside of an endostome segment (a spore is in the lower right corner). All from type. 1994] LARA ET AL.: ORTHOTRICHUMMACROCEPHALUMSP. NOV. FiGURE21. Map of Iberian Peninsula; dots indicate known distribution of Orthotrichum macrocephalum. 407 exostome) allow the distinction of 0. macrocephalum. Orthotrichum flowersii Vitt, related to 0. pumilum and 0. pallens Brid. by Vitt (1971 b), who also emphasized its superficial similarity with 0. obtusifolium Brid., could be considered close to 0. macrocephalum. Both mosses show convergent characters, considered apomorphic by Vitt (197 la) and Lewinsky (1977, 1993): scarce branching, small size, leaves erecto-appressed, and leaf apex obtuse or rounded. Such characters give these mosses the peculiar compact habit (Fig. 13) that, we think, is related to an effective morphological adaptation to severely xeric environments. However, as shown in Table 1, O0.macrocephalum and O. flowersii are well separated by their capsule characters. Orthotrichum macrocephalum is superficially similar to some Orthotrichum species reported from TABLE1. Comparisonof the species of Orthotrichumsection Diaphana with obtuse or roundedleaf apices. Data for 0. flowersii and 0. pumilum after Vitt (1973), 0. tristriatum after Lewinsky (1984), and 0. crenulatum after Lewinsky (1992). 0. macrocephalum 0. flowersii 0. pumilum 0. tristriatum0. crenulatum Leaf apex-I 1. Rounded; 2. Obtuse; 3. Acute 1,2 1,2 Leaf apex-II 1. Mucro; 2. Papillose-crenulate 0 0, 1 Leaves 1. + Plane; 2. Concave and carinate 2 2 1 2 1 Capsule length (mm) 1.3-2.2 1.0-1.4 1.2-1.5 1.3-1.7 ca. 1.0 Stomata 1. ? Completely covered by protruding subsidiary cells; 2. Hemicryptopore 1 1 2 1 2 1 2 2 3 Stomate position 1. Upper half capsule; 2. Middle; 3. Lower half capsule Neck 1. Sharply contracted; 2. Gradually contracted 2 2, 3 1,2,3 0 0, 2 1 2 1,2 2 2 Endostome-I 1. Uniseriate; 2. Biseriate 2 1 (2) 1,2 1 2 Endostome-II 1. Smooth; 2. Rough (scabrous); 3. Papillose 3 2 1 2,3 1,2 Endostome-III 1. Tuberculate; 2. Not tuberculate 1 2 2 2 2 Exostome 1. Only individual papillae; 2. With papillae fused in crests; 3. With smooth ridges 2 1, 2? 1 3 1 Calyptra 1. Naked; 2. Hairy 1 1,2 1 2 1 Sexual condition 1. Cladautoicous; 2. Gonioautoicous 1 1,2 1,2 1,2 1,2 2 1 408 [VOL.97 THE BRYOLOGIST the Iberian Peninsula: 0. pumilum Sw., 0. pallens Bruch ex Brid., and 0. stellatum Brid. The first two differ from the new moss by, e.g., their half immersed stomata, and leaves scarcely carinate and with nonrounded apices. Orthotrichum stellatum, though also having stomata largely hidden by the subsidiary cells, differs from 0. macrocephalum by its capsules gradually contracted to the seta and markedly constricted below the mouth. All of them differ from 0. macrocephalum by their soft or finely papillose endostome segments, not densely papillose nor tuberculate as in the new moss. Among the other European mosses, 0. rogeri Brid. and 0. microcarpum De Not. are the most similar to 0. macrocephalum. The former differs by its leaves excavate in the base, with large papillae, and by its gradually narrowed neck and emergent capsules. Orthotrichum microcarpum has half-immersed stomata and soft endostome segments. As for the relationships of 0. macrocephalum, we agree with Lewinsky (pers. comm.) in a proximity to 0. diaphanum Brid. According to this author, one of the most relevant features of the new moss is the strong papillosity of the endostome segments, a character also found in 0. diaphanum. Moreover, both mosses have a connective basal membrane between the endostome segments (although more papillose in 0. macrocephalum), as well as a similar type of calyptra; in addition, both produce gemmae, and are xerophilous and nitrophilous. These similarities suggest that 0. macrocephalum and 0. diaphanum could have diverged from a common ancestor. Orthotrichum macrocephalum shows some plesiomorphic characters, such as the exostome ornamentation, and others more advanced, such as the endostome with only eight segments and the small size of leaf cells. ACKNOWLEDGMENTS Our deepest thanksare due to Dr. Jette Lewinskyand Dr. Dale H. Vitt for confirmingthe new species and for makinghelpful comments on the manuscript. LITERATURECITED LARA,F. 1993. Estudio Biogeografico de los Bri6fitos Epifitosde los Melojaresdel SistemaCentralOriental (Sierrasde Gredos, Guadarramay Ayllo6n).Doctoral dissertation,UniversidadAut6nomade Madrid. J. 1977. The genus Orthotrichum.MorphoLEWINSKY, logical studies and evolutionaryremarks.Journalof the Hattori BotanicalLaboratory43: 31-61. ? 1984. OrthotrichumHedw. in SouthAmerica1. Introductionand taxonomicrevision of taxa with immersed stomata. Lindbergia10: 65-94. ? 1992. The genus OrthotrichumHedw. (Orthotrichaceae,Musci)in SoutheastAsia. A taxonomicrevision. Journal of the Hattori Botanical Laboratory 72: 1-88. ? 1993. A synopsis of the genus Orthotrichum Hedw. (Musci, Orthotrichaceae).Bryobrothera2: 159. VITT,D. H. 1971a. The infragenericevolution, phylogeny, and taxonomyof the genus Orthotrichum (Musci) in North America.Nova Hedwigia21: 683-711. from western ? 1971b. New taxa of Orthotrichum North America. THE BRYOLOGIST 74: 159-164. in ? 1973. A Revision of the Genus Orthotrichum North America,North of Mexico. BryophytorumBibliotheca, 1. Lehre.