A REVISION OF RIGODIUM (MUSCI: RIGODIACEAE) By WENDY B. ZOMLEFER A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1991 Copyright 19 91 by Wendy B. Zomlefer ACKNOWLE DGMENTS I express my deepest appreciation and gratitude to Dana Griffin, III, for his limitless patience and enthusiastic guidance throughout my graduate program. I also thank Walter S. Judd, who also generously provided much encouragement and many helpful criticisms. The other members of my committee, Bruce J. MacFadden, Jonathan Reiskind, and James W. Kimbrough have also greatly assisted in my project and have improved the quality of the dissertation with their comments. A very special thank-you goes to Kent D. Perkins for his help in all computerized aspects of this study, including data-base management, word processing and processing of loans. I appreciate also the advice and hospitality of William R. Buck and Richard Harris (curators at the New York Botanical Garden) during my two trips to their institution; Bill Buck has been especially instrumental in my development as a bryologist. I could not have completed this revision without the time and patience of many other individuals. Thomas J. Whitmore, Stephen B. Linda, and Carmine A. Lanciani helped with aspects of the statistics; w. Mark Whitten, Stephen J. Walsh, and Douglas D. Turley assisted as computer consultants. Donna S. Williams spent numerous hours helping me with the preparation of my specimens for the SEM. Norris 111 H. Williams, my job supervisor at the Florida Museum of Natural History, has been especially generous with his computer facilities, as well as sympathetic to the problems surrounding my concurrent employment and school activities. Howard Crum provided excellent instruction during my tenure as his assistant at the University of Michigan Biological Station and graciously sent me an unpublished manuscript related to my dissertation work. Daniel B. Ward and Dan H. Nicholson advised me on several difficult nomenclatural problems. Rhoda J. Bryant and Dianna C. Carver helped with word processing. I thank also the curators of the herbaria listed in the materials and methods section for the extended loans of their specimens. Travel money for three trips to study bryophytes (one to Michigan and two to Puerto Rico) was provided by the Department of Botany at the University of Florida. By their consistent concern about my graduate program over the past five years, Graig D. Shaak, Gary S. Morgan, and Laurie Wilkins (all of the Florida Museum of Natural History) , helped to keep my spirits up. In this regard, I also thank Susan W. Williams and my sister, Kayla S. Zomlefer, for their cheerful support. Finally, I thank my parents, Jack and Dorothy Zomlefer, who have always encouraged and supported my academic pursuits, even in my formative years when females were neither expected nor encouraged to excel in the sciences. IV TABLE OF CONTENTS page ACKNOWLEDGMENTS iii ABSTRACT vii INTRODUCTION 1 TAXONOMIC HISTORY 3 MATERIALS AND METHODS 2 0 MORPHOLOGY 25 Axes 25 Leaves 28 Axillary Hairs 3 0 Paraphyllia and Pseudoparaphyllia 31 Perichaetia and Perigonia 32 Sporophy te 33 Spores 34 Chromosome Number 34 PHYLOGENY 57 Characters for Analysis of Representative Genera of Superfamily Leskeacanae 66 Results of Analyses of Genera 69 Characters for Rigodium Species 72 Results of Analyses of Rigodium species 74 Taxonomic Philosophy Concerning Species 77 PHENETIC STUDIES 99 Choice of OTUs and Choice of Specimens 100 Choice of Characters 103 Results of the Principal Component Analyses 105 PHYTOGEOGRAPHY 117 TAXONOMIC TREATMENT 122 Key to the Species of Rigodium 125 1. Rigodium toxarion (Schwagr.) Jaeg 130 2. Rigodium brachypodium (C. Mull.) Par 167 3 . Rigodium adpressum Zomlefer 194 4 . Rigodium implexum Kunze ex Schwagr 207 5 . Rigodium pseudo-thuidium Dus 220 NOMINA AMBIGUA AND NUDA 234 LITERATURE CITED 238 APPENDICES A OTUS (COLLECTIONS) USED IN THE PHENETIC ANALYSES 248 B DETERMINATION OF MINIMUM NUMBER OF MEASUREMENTS PER CHARACTER 254 BIOGRAPHICAL SKETCH 258 VI Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy A REVISION OF RIGODIUM (MUSCI: RIGODIACEAE) By Wendy B. Zomlefer May 1991 Chairman: Dana Griffin, III Major Department: Botany Rigodium Kunze ex Schwagr. , a genus of tropical to austral-temperate pleurocarpous mosses, is comprised of five species (plus two varieties) . Prior to this study, 26 species were recognized, with five additional species generally accepted as belonging to other genera. Species of Rigodium. all dioicous, have wiry stems and branches, strongly dimorphic stem and branch leaves, extremely incrassate leaf cells that are prorulose to varying degrees (depending on the species), and hypnoid peristomes. The habit varies from arborescent with a well-developed stipe (R. toxarion, R. adpressum. and R. brachvpodium) to more derived forms with either prolific (R. implexum) or reduced (R. pseudo-thuidium) branching. The genus has a disjunct distribution in Central and South America and southeastern Africa. The plants, usually epiphytic or terrestrial, generally grow in moist, montane forests. The center of diversity, where all five species occur, is in the Andean Cordillera along the Chilean- Argentinian border in central Chile. vn Observations of morphology, including those made with scanning electron microscopy (SEM) , compose the basis of this revision, which includes computer-assisted analyses of phenetics (Principal Component Analysis, PCA) and cladistics (Phylogenetic Analysis Using Parsimony, PAUP) . One previously undescribed species (R. adpressum) and two new combinations at the varietal level (R. toxarion var. robustum and R. brachvpodium var. tamarix) are presented. Rigodium is maintained within the monotypic Rigodiaceae, possibly related to the Thuidiaceae. vm INTRODUCTION As treated here, the genus Rigodium Kunze ex Schwagr. consists of five species (including two varieties) of austral -temperate to tropical pleurocarpous mosses from Hispaniola, Central and South America, eastern Africa, and Madagascar. The center of diversity of Rigodium. where all five species occur, is in the Andean Cordillera along the Chilean-Argentinian border in central Chile. The plants typically grow as epiphytes (or less often terrestrial, corticolous, or saxicolous) in moist forests at moderately high altitudes (up to ca 3800 m) . Although 31 species have been included within Rigodium. no comprehensive work had been published for the genus until the present revision. The genus itself is well-defined and recognizable by the dendroid to frondose habit with wiry stems and branches and often a well-differentiated stipe (lower secondary stem) . The strongly dimorphic stem and branch leaves are unusual in the marked tendency toward ecostate stem leaves (at least those of the "stipe" or lower stem) . Stem leaves are typically strongly spreading to squarrose, wet or dry. Leaf cells are generally rounded- quadrate (alar region and margins) to oblong (upper and midlaminar areas) and incrassate throughout. The plants are dioicous, and the peristome is hypnoid (Zomlefer and Buck, 1990) . This treatment represents the first attempt to completely review all pertinent literature and specimens in order to (1) ascertain the species and their relationships within the genus and (2) to determine the position of the genus (in a monotypic family) within the scheme of bryophyte phylogeny using cladistics. The results presented here are based on gualitative and quantitative analysis of morphology, ecology, and anatomy of over 2,400 herbarium specimens. This study is especially pertinent since many of the habitats where Ricr odium occurs (mainly subtropical to temperate rain forests) are threatened by human activities (as for example, logging in the Valdivian forests in Chile) . TAXONOMIC HISTORY The genus Rigodium was established by Schwagrichen in 1845 with original material of the new species, Rigodium implexum, coming from southern Chile (Schwagrichen, 1845; Zomlefer, 1990) . The name is taken from the Greek word "rigos" (= rigid) in reference to the extremely stiff and wiry stems and branches. Although Miiller (1845, 1851) initially suggested maintaining this new genus rather as a section within Hvpnum , the name became well-accepted in the literature, with even Miiller himself eventually describing six species using Rigodium as the genus name. In addition to R. implexum. 19 new species were later described, plus 11 more transferred to Rigodium from Hvpnum (ten species) and Leskea (one species) . Of these 31 valid species names (Wijk et al. , 1967, 1969; Crosby, 1979), five have been now generally accepted as belonging to other genera: R. dentatum Dix. = Rhvnchostegiella zeyheri (C. Mull.) Broth., R. reflexum (Stark.) Kindb. = Brachvthecium reflexum (Stark.) B. S. G. , R. schlosseri (Sendtn.) Kindb. = Camptochaete schlosseri (Sendtn.) Par., R. vagum (C. Mull.) Reichdt. = Camptochaete vaga (C. Mull.) Broth., and R. varium (Hedw.) Kindb. = Amblvsteoium varium (Hedw.) Lindb. In addition, four more Rigodium types examined in the initial stages of this study have also been reassessed (Zomlefer & Buck, 1990) : R. toxarioides Broth. & Par. (Fig. 1) and R. crassicostatum Bartr. in Christ. (Fig. 2) both = Eurhvnchium praelonaum (Hedw.) B. S. G. ; R. pteriavnandroides (Broth.) Broth. (Fig. 3) = Helicodontium pervirens (C. Mull.) Par.; and R. riparium Sehnem (Fig. 4) = Helicodontium complanatum Broth. This leaves a total of 22 valid epithets (Table 1) incorporated into the present study — 2 0 associated with Hispaniola and Central and South America, and one each with eastern Africa and with Madagascar. The authors of the original species descriptions have generally emphasized subtle differences in characters, such as the relative size and fragility of the plants and the coarseness of the serrations on the leaves. By apparently comparing type specimens only, the authors did not sufficiently evaluate the intergradation of these characters throughout the genus and thus may have overlooked numerous specimens which bridged the apparent morphological gaps between the type specimens. The most obvious "species" based on the old literature are R. pseudothuidium/R . hvlocomioides (both with distinct habit and a reduced costa in the stem leaves) and R. implexum (very stiff plants with unusual right-angle branching) . Certain names tended to be associated only with collections from the particular country of the type specimen, such as "R. solutum" with Ecuador and "E- leptodendron" with Bolivia (see Table 1) . Adding to the confusion, authors of floristic treatments tended to lump indiscriminately several names in synonymy, such as Jaeger [1878; R. toxarion = R. implexum. R. brachypodium. and Hypnum (Rigodium) solutum] , Miiller [1882, Hvpnum (Rigodium) argentinicum = R. implexum and R. brachvpelma (brachypodium) 1 . and Mitten [18 69; Hypnum (Rigodium) toxarion = H. implexum. H. brachypodium. H. solutum. and R. lechleri (arborescens) ] . Brotherus ' (1925) key to 17 species separates out only the few obvious forms (i.e., R. implexum. R. hvlocomioides . and several species no longer included in Rigodium) and lumps the remaining 12 species (by country) under the first general dichotomy of the key (habit type) . The great need for a full-scale revision of Rigodium has been noted by authors from Reimers (192 6) to Robinson (1975) . In reviewing Chilean collections of bryophytes and examining numerous specimens of Rigodium in particular, Reimers (1926) and Herzog (1938, 1954) both concluded that making any decisions about the taxonomic validity of Rigodium species was virtually unfeasible without monographic studies. In fact, Reimers promised a forthcoming revision (which never appeared) . Herzog (1939) and Bartram (1960) each described a new species of Rigodium (R. pendulum and R. crass icostatumf respectively) , while at the same time admitting the near impossibility of applying any specific names without a critical revision of the entire genus . Other than the keys of Brotherus (1909, 1925), no attempt has been made to distinguish all the species of the genus, although several workers have treated a few species of Rjqodium with a regional, floristic perspective. Most floras do not include descriptions or keys but only list those species names (and sometimes the specimens) associated with the area (e.g., Seki, 1976). Notable exceptions are the floras of Sehnem (1976) and Robinson (1975), which include keys and some discussion comparing several species. These two floras, however, are restricted in scope and do not address Rjqodium as a whole. Sehnem' s keys for seven species of Rjqodium in his treatment of the mosses of southern Brazil use vague characters such as a "delicate habit, similar in aspect to Ptergynandrum or Thuidium. " He described two new species, R. riparium and R. pallidum. Rjqodium riparium Sehnem is actually Helicodontium complanatum Broth. (Zomlefer & Buck, 1990) , and R. pallidum Sehnem has been reduced to synonymy with R. toxarion (Schwagr.) Jaeg. in the present study. Robinson's treatment of the mosses of the well-collected Juan Fernandez Islands includes detailed discussions of four species (R. arborescens, R. hylocomioides. R. toxarion and R. robustum) with comments on his opinions of synonomy and relationships to several other species on mainland Chile. By concentrating on a small, well-collected area, he apparently made some assumptions about Rjqodium species that reflect better the local variation rather than that found throughout whole range of the genus. His conclusions are commented on under the appropriate species in this study. Coupled with problems in delimitation of the species is a lack of agreement on the affinities of Rigodium to other groups. As with many pleurocarpous taxa, Rigodium was initially allied with Hypnum/Hypnaceae (e.g., Miiller, 1851). By the early twentieth century, more pleurocarpous families had been delimited, and Rigodium was moved to the Brachytheciaceae by Brotherus (1909) . Later, he (1925) transferred it to the Lembophyllaceae. Associating the genus with these two families has persisted until recently. For example, Robinson (1975) placed Rigodium in the Brachytheciaceae due to its similarity (stipes and strong heterophylly) with Stokesiella [horn, illeg. ; = Eurhvnchium fide Buck (1988)]. More recent publications (Crosby & Magill, 1981; Vitt, 1982; Walther, 1983) maintain Rigodium under the Lembophyllaceae, although the validity of this family, as first conceived by Brotherus, has continued to be guestioned (Crum, 1991) . Buck (1980a) reduced the Lembophyllaceae to two genera (Camptochaete and Lembophyllurrn and suggested placement of Rigodium in the Thuidiaceae, a move supported by Vitt (1984) . According to Buck, pertinent characters linking Rigodium to the Thuidiaceae include the pinnate branching, similar leaf shapes, short leaf cells, and strong single costae. Bartram (1949) was the first to suggest placement of Rigodium in a separate family, if not the Brachytheciaceae 8 or Leskeaceae (in which he included the Thuidiaceae) . Crum (1981, 1984) recently erected the monotypic family Rigodiaceae, which has been accepted by some authors (Buck & Vitt, 1986) , and tentatively supported by others (Walther, 1983) . Although he later (1991) agrees with Buck (1980a) and acknowledges a close resemblance of Riqodium to the Thuidiaceae, Crum maintains that the "stipitate growth, smooth leaf cells, and absence of paraphyllia" merit separate familial status for the genus. The present study recognizes five species (including two varieties) of Riaodium. including one species described here for the first time: R. adpressum Zomlefer, R. brachypodium (C. Mull.) Par. var. brachypodium, R. brachypodium (C. Hull.) Par. var. tamarix (C. Mull.) Zomlefer, R. implexum Kunze ex Schwagr. , R. pseudo-thuidium Dus., R. toxarion (Schwagr.) Jaeg. var. toxarion. and R. toxarion (Schwagr.) Jaeg. var. robustum (Broth, in Skottsb.) Zomlefer. Considering the initial 22 epithets, the recognition of only five species represents a 77% rate of over-description. This figure is consistent with moss revisions in general: according to Touw's (1974) survey, 73 to 79% of published specific and infraspecif ic names have been reduced in synonymy in moss revisions from 1901 to 1974. The results of the preliminary cladistic study and character analysis in this revision indicate that Rig odium is phylogenetically intermediate between Echinodium (Echinodiaceae) and Thuidium (Thuidiaceae) , and that all three taxa are basal in Buck and Vitt's (1986) superfamily Leskeacanae of the Hypnales (see detailed discussion in section on phylogeny) . With Echinodium as an outgroup for Riqodium, cladistic analyses identify R. toxarion as the most ancestral species, R. implexum and R. pseudo-thuidium as the most derived sister-species in the genus, and R. brachypodium and R. adpressum as phylogenetic intermediates. FIG. 1. Type of Riqodium toxarioides Broth. & Par. = Eurhynchium praelongum (Hedw.) B. S. G. A. Habit. B. Detail of stem. C. Stem leaf. D. Branch leaf. E-H. Areolation of leaf. E-F. Basal cells. G. Median cells. H. Detail of upper costa showing dorsal spine. All from Apollinaire s.n. , 1905 (H-BR) . Copyright 1990 by the American Bryological and Lichenological Society. Reprinted with permission from The Bryoloqist 93 (3) : 305. 11 FIG. 2. Type of Riqodium crass icostatum Bartr. in Christ. = Eurhvnchium praelonqum (Hedw.) B. S. G. A. Habit. B. Detail of stem. C. Stem leaf. D. Branch leaf. E-H. Areolation of leaf. E-F. Basal cells. G. Median cells. H. Detail of upper costa showing dorsal spine. All from Christophersen & Men land 907 (BM) . A and B copyright 199 0 by the American Bryological and Lichenological Society. Reprinted with permission from The Brvoloaist 93 (3) : 305. 13 FIG. 3. Type of Rigodium ptericrynandroides (Broth.) Broth. = Helicodontium pervirens (C. Hull.) Par. A. Habit. B. Stem leaf. C. Branch leaf. D-G. Areolation of leaf. D. Basal cells. E. Median cells. F. Acumen. G. Detail of upper costa showing dorsal spine. H. Capsule. All from Lindman 52 (H-BR) . Copyright 1990 by the American Bryological and Lichenological Society. Reprinted with permission from The Bryoloqist 9 3 (3) : 3 06. 15 FIG. 4. Type of Riqodium riparium Sehnem = Helicodontium complanatum Broth. A. Habit. B. Portion of plant with sporophyte and perigonia. C. Stem leaf. D. Branch leaves. E-G. Areolation of leaf. E. Basal cells. F. Median cells. G. Acumen. H. Capsule. All from Sehnem 21515 (PACA) . Copyright 1990 by the American Bryological and Lichenological Society. Reprinted with permission from The Brvologist 93 (3): 307. 17 1 ' 0.25mm 18 w e c o c >1 in CD X P T3 C RJ g 3 •H TS O B •H O W P CN CN 0) £1 p 4-1 o c o •H p 3 XI •rH p p cn •H 0) x (0 c ■r-l Cn ■H P s O 0) d) c x Eh -P c • -H >1 T3 T3 0) -H X! 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Eh P En «l p x: Eh X 0) :1 o 1 p H 3 0 -H 0 CO 03 g d) c 0) en p Eh N P (1) X g E 3 3 T3 rH •H 3 rH 73 iH C (0 ai Q 0 :3 S u g 3 P (1) 0 -H c a> Q :3 a u 0) 3 C (1) p p 0) 0 CO 3 Q g 3 •i-t -0 •H 3 £! P I O T3 3 0) CO J3 10 P P O CO J3 p o p CQ P 03 fa 03 Eh :3 a l,0 and l->l,o, respectively. In the second analysis (Pleuroziopsis as outgroup) , the results are much less resolved; 27 equally parsimonious trees (53 steps, CI=0.717) were discovered. The consensus tree (Fig. 18B) is basically polytomous, although Pteriqynandrum, Leskea . and Pseudoleskea are established as a monophyletic group. However, one of the 2 7 trees is identical in topology to the cladogram derived with Thamnobryum as the outgroup (Fig. 17), and in many trees, (e.g., Fig. 18A) , Echinodium is basal within the group, with Riqodium phylogenetically adjacent. With Thamnobryum and Pleuroziopsis functioning as a combined outgroup, 33 most parsimonious trees were generated (54 steps, CI=0.704). The use of both taxa simultaneously to root cladograms was problematical as one or the other of these genera appears within the ingroup in several of the trees (i.e., the tree could not be rooted so that the ingroup was monophyletic) . This issue weakens the validity of using both these taxa as outgroups. However, several of the trees (where the combined Pteriavnandrum-Thamnobrvum does appear as the outgroup) are similar in topology to those discussed above (e.g., Fig. 17) and have Echinodium in a cladistically basal position, followed by Riqodium and Thuidium. 72 The consensus tree of the previous analysis (Fig. 18B) indicates that more detailed phylogenetic investigations (with more genera) are needed to better define the relationships of the families within the Leskeacanae. The present analyses do support maintaining Rigodiaceae as a monotypic family, since inclusion with Thuidiaceae (Thuidium) would result in a paraphyletic family. Characters for Riaodium Species The matrices of Tables 4 and 5 are the data sets used in the analyses of Ricrodium species. Eight characters were polarized using Echinodium as the outgroup. Although the number of OTUs differ (see discussion following) , the number of characters remained constant for both analyses. Six characters are qualitative, and two are quantitative (one continuous and one discontinuous) . The problems in forming taxonomic characters from measurements are summarized in Almeida and Busby (1984). The approach in this revision (see Fig. 19A and B) involves the traditional method of scanning the full range of the material and partitioning the scale into classes of varied range. The character states are, thus, somewhat arbitrarily delimited. Only the characters with an obvious gap (number of cells in the intramarginal band, Fig. 19A; stem leaf decurrency/total leaf length, Fig. 19B) were used in the cladistic analysis, although three other characters (intramarginal vs. midlaminar cell length, Fig. 19C; stem leaf length/width, Fig. 19D; and stem leaf acumen length/length from point of 73 insertion, Fig. 19E) show basic trends. These three latter features are discussed under the appropriate species discussions following the diagnoses in this revision. The following lists the characters as their derived state ("1" in Tables 4 and 5; character 6 has two derived states, "1" and "2.") 1. Rooting at tips. As discussed in the morphology section, several species of Ricrodium (e.g., R. toxarion) develop rhizoid clusters at the tips of stem and branches and thereby form new plants. 2. Loss of well-differentiated stipe. Two species (R. implexum and R. pseudo-thuidiuml lack the arborescent habit and the associated well-developed stipe (lower unbranched portion of the stem) . 3. Right angle branching. In R. brachypodium var. tamarix (Fig. 38A) , R. implexum (Fig. 44G) , and R. pseudo- thuidium (Fig. 46A) , the primary branches are spreading, evenly spaced and arise at right angles to the stem. 4. Decurrent stem leaves. Stem leaves were ranked as "decurrent" when the stem leaf decurrency/total leaf length ratio exceeded 8% (Fig. 19B) . Note that a percentage greater than 14 is an autapomorphy for R. adpressum. 5. Uneven midlaminar cell walls. In R. toxarion. (as in Echinodium) , these cell walls are not very porose (Fig. 27J) , compared to the other species with conspicuously uneven walls (e.g., R. pseudo-thuidium. Fig. 4 6M) . 74 6. Visibly prorulose midlaminar cells. In R. toxarion, the cells are prorulose, but not easily discernible (Fig. 27J) , while in R. adpressum, R. implexum and S- pseudo-thuidium these cells are noticeably thickened at the end walls (e.g., Fig. 4 6M) . In R. brachvpodium (both varieties) the end walls project as dorsal papillae (prorulae; Fig. IOC and D) . In the matrices, the thickened but not papillose condition is indicated as "1," and the papillose extreme, as "2." This does not, however, mean that condition "2" is necessarily more derived that "1;" other than the fact that "0" is basal (outgroup comparison) , the actual sequence of events (i.e., 0->l->2, 0->2->l, or l<-0->2) is unknown here (see discussion of results) . 7. Seven or greater cell rows in intramarginal band. A natural division in the number of cell rows is apparent at seven cells (Fig. 19A) , with R. implexum and R. pseudo- thuidium both characterized by this derived condition. . 8. Extremely thickened cell walls of intramarginal band. In R. toxarion (Fig. 27K) the intramarginal band is barely visible, even in cross section (Fig. 271) . in the other four species, the walls are extremely incrassate and easily distinguished from the midlaminar cells, even in surface view (e.g., Fig. 46L) . Results of Analyses of Riaodium Species The data sets (Tables 4 and 5) for the two analyses were identical except for the configuration of R. brachypodium. In the first analysis, this species was split 75 into its two varieties, R. brachvpodium var. brachvpodium and R. brachvpodium var. tamarix. in order to test the monophyly of the species (Table 4) . In the second examination (Table 5) , the species was assumed to be monophyletic with two polymorphous character states (3, right angle branching; 4, decurrent stem leaves). Figure 20 is the single most parsimonious tree (11 steps, CI=0.818) for Rigodium species with the two varieties of E- brachvpodium designated as separate OTUs. Rigodium toxarion is basal, followed by R. brachvpodium and R. adpressum, and R. pseudo-thuidium and R. implexum are derived sister-species. Of interest is that R. brachvpodium is not monophyletic here, but paraphyletic. The only parallelism involves character 3 (right angle branching) for R. brachvpodium var. tamarix and the R. implexum-R. pseudo-thuidium clade, which may reflect that the ramification is actually different in these two instances. In R. brachvpodium var. tamarix the branches are regularly pinnate (Fig. 38A) , while the branching of the other two species is irregularly pinnate. In fact, the habit type of R. implexum (Fig. 22A) may have been derived from a form like R. pseudo-thuidium with several innovations arising from the main stem (Fig. 22B) ; see also discussion under R. pseudo-thuidium^ . The only reversal in the cladogram is where "rooting at the tips" (1) was lost for the R. implexum-R. pseudo- thuidium clade, possibly because this feature is correlated 76 with the loss of the aborescent or frondose habit. This analysis also suggests that the direction within character 6 (degree of prorulosity) is 0->2->l, i.e., the less prorulose state (1) is secondarily derived from the extreme papillose type (2) . In the second analysis, R. brachvoodium was considered to be a monophyletic multistate taxon (polymorphic characters 3 and 4; Table 5). Two equally parsimonious cladograms were generated (12 steps, CI=0.917; Fig. 21A and B) , with one tree (Fig. 21B) equivalent to the strict consensus tree. In contrast to the previous analysis, where R. adpressum is more derived than R. brachvpodium (which is paraphyletic) , the position of the former species here is either phylogenetically intermediate between R. toxarion and R. brachvpodium (Fig. 21A) or unresolved (Fig. 21B) . The other portions of the tree (R. toxarion basal; R. implexum- B- pseudo-thuidium terminal sister-taxa) are supported as in the previous analysis. Within the multistate R. brachvpodium , homoplasy is indicated for characters 3 (right angle branching) and 4 (decurrent stem leaves). Also, the direction of evolution for character 6 is towards increasing degree of prorulosity (0->l->2), instead of the secondarily derived reduction in the previous analysis. For both analyses, character 1 (rooting at tips—which reverses within the terminal portion) is a defining feature of Rigodium. In addition to this feature, autapomorphies of 77 the genus (i.e., synapomorphies of its species) include the presence of a differentiated intramarginal band of cells and extremely incrassate cells. Thus, the genus is clearly monophyletic. Taxonomic Philosophy Concerning Species As suggested in Budd and Mishler (1990), the working definitions of species used by taxonomists are, in general, either phenetic or basically cladistic. In this revision, a species was defined primarily as a phenetically cohesive unit that is separated from other similar entities by a consistent morphological gap. Monophyly (cladistic approach) was examined secondarily in the analyses discussed above. Riqodium toxarion (the basal species) is metaphyletic (Donoghue, 1985; Mishler, 1985), as no autapomorphies define it. Riqodium adpressum. R. implexum and £• pseudo-thuidium are monophyletic, each distinguished by the following autapomorphies: (1) R. adpressum: appressed leaves, strongly revolute leaf margins, decurrency of stem leaf greater than 14% of total leaf length (Fig. 19B) , low central papillae in some cells of the stem leaf decurrency, and intramarginal cells shorter than the midlaminar cells (Fig. 19C) ; (2) R. pseudo-thuidium : reduction of secondary and loss of tertiary branching and loss/reduction of stem leaf costae; and (3) R. implexum: free-living, terrestrial "tumbleweed" habit with extremely wiry axes and profuse branching. As discussed above, R. brachvpodium may be monophyletic or paraphyletic. Since the strong character 6 78 (end walls with prorulae) and intermediate habit forms (detailed in the discussion of R. brachvpodium var. brachvoodium) link the two varieties, from a practical standpoint this taxon is considered as a single species in this revision, and it is considered probably monophyletic. A variety here is defined as a monophyletic (or metaphyletic) group within a species that is separated from other such entities by a small morphological gap (Wilken & Hartman, 1991) . Thus, the variety in the traditional sense of an allopatric race (Mayr, 1969), i.e., having one to few conspicuous differences associated with a certain geographical range, is not applied in this revision (see Stuessy, 1990, for discussion on infraspecif ic categories). The category of variety is applied within two species, R. toxarion and R. brachvpodium. Although both varieties of R. toxarion are sympatric, the traditional varietal concept somewhat applies since R. toxarion var. robustum is restricted to the Juan Fernandez Islands. This variety is additionally defined by the autapomorphy of narrow branch leaves (see details under discussion of R. toxarion var. robustum) , while R. toxarion var. toxarion is metaphyletic. As discussed above, the two varieties of R. brachvpodium here are considered to comprise one species due to the presumed synapomorphy of prorulae, as well as intermediates in habit type. Rigodium brachvpodium var. tamarix is defined by the autapomorphy of the habit type (elongated 79 stems with + regularly pinnate branching) , while R. brachvpodium var. brachvpodium is considered metaphyletic. B U O (0 u a 3 (0 c (0 4J >iO C (0 a) ^ & (0 O X3 H O >i E-" T3 0) w • o ~ &vo O co • ^-i a\ cm • -p .q VD +J (0 H -H EH > c O T3 -H H C o .* -P o w 81 <* 0 *>&%> % Q0, V H cr UJ Q X o CD to UJ < z < < 2 LL > I 3 < LL EC LU Q. D 00 X*§ °i. * CD O o o cC CD o sz CD -t— < Q. CD 7,11,13 9,14 7,13 M5',16' =3 CD CO Q. 4b',15d',16d' ' parallelism = reversal polymorphic characters a =1,2,3 c = 0,2 b=1,2 d=0,1 O CD o -g ■2 9 O O }- -C -Q O -C Q_ v 3 ■^ CD & W -9 Q. FIG. 19. Morphological Trends in Riqodium species. A. Number of cell rows in the intramarginal band of stem leaves, showing division at 8 cells. B. Range of variation in stem leaf decurrency length/total leaf length, showing gaps at 8 and 13. C. Range in intramarginal and marginal cell lengths. D. Range in stem leaf length/width. E. Range in stem leaf acumen length/ leaf length from point of insertion. TOX = R. toxarion; BRAB = R. brachypodium var. brachypodium; BRAT = R. brachypodium var. tamarix; ADP = R. adpressum; PSE = R. pseudo-thuidium ; IMP = R. implexum. Asterisks (*) in B and C indicate autapomorphies (for R. adpressum) . Character groupings depicted in A and B were used in cladistic analyses. A IMP PSE ADP BRAT BRAB TOX 1 -i 1 1 1— 4 6 — i 1 1 8 10 Number of Cells C IMP PSE ADP BRATl- BRAB TOX B IMP PSE ADP BRAT BRAB TOX 90 T T i 1 * — i i 1 T" 5 10 15 20 Decurrency L/Total Leaf L 10.0 20.0 30.0 40.0 Cell Length (jjm) ' lintramarginal i h midlaminar IMP PSE ADP BRAT BRAB TOX ~~i 1 1 1 1 0.75 1.25 1.75 Stem Leaf L/W IMP PSE ADP BRAT BRAB TOXL i i i 1 1 20 40 60 Acumen L/Leaf L 91 Table 4. Data matrix for the cladistic analysis of Ricrodium species where the varieties of R. brachypodium are treated as separate OTUs. Echinodium functioned as the outgroup in the analysis. Species Characters 12345678 Echinodium 00000000 R. toxarion 10000000 R- brachypodium var. brachypodium 10011201 R- brachypodium var. tamarix 10101201 R. adpressum 10011101 R. implexum Ollliiii R. pseudo-thuidium 01111111 FIG. 20. Most parsimonious tree in analysis of Rigodium species with the two varieties of R. brachypodium ("brat" and "brab") treated as separate OTUs. For characters see the text; for the character states see Table 4. 93 5 6(0*2) parallelism reversal 94 Table 5. Data matrix for the cladistic analysis of Rigodium species where R. brachypodium is treated as monophyletic (both varieties = 1 OTU) . Echinodium functioned as the outgroup in the analysis. Polymorphic character: a = 0,1. Species Echinodium R. toxarion R. brachypodium R. adpressum R. implexum R. pseudo-thuidium 1 0 1 1 1 0 0 2 0 0 0 0 1 1 Characters 3 0 0 a 0 1 1 4 0 0 a 1 1 1 5 0 0 1 1 1 1 6 0 0 2 1 1 1 7 0 0 0 0 1 1 8 0 0 1 1 1 1 FIG. 21. The two most parsimonious trees in analysis of Rigodium with R. brachypodium ("bra") treated as one OTU (i.e., monophyletic) . Cladogram B is also equivalent to the consensus tree. For characters see the text; for the character states see Table 5. 96 ' parallelism ^reversal Bx 2 ech FIG. 22. Habits of sister groups R. implexum and R. pseudo-thuidium . A. R. implexum (Dusen 409 , 0) . B. R. pseudo-thuidium plant with innovations, mistaken for R. implexum (Dusen 618 , JE) . 98 PHENETIC STUDIES As noted in the introduction and taxonomic history, the numerous described "species" of Rigodium are very similar morphologically and are often confused with one another in floristic literature. Preliminary examinations of the specimens indicated two apparently well-defined groups due to their distinctive habits (IL_ implexum and R^. pseudo- thuidium/R. hvlocomioides) , and two more variable and overlapping complexes encompassing most of the other species names (e.g., a R^ toxarion/qracile group and R. brachvpodium/arborescens group) . Phenetic analyses were conducted in order to evaluate more objectively the possible morphological boundaries of these presumed species. The multivariate ordination technigue, principal component analysis (PCA) , was employed using the software package NTSYS-pc (Rohlf, 1989) on an IBM-compatible PC. Sneath and Sokal (1973), Wiley (1981) and Duncan and Baum (1981) discuss this multivariate technigue in more detail. Basically, principal components analysis is a method of data reduction that aids in detecting patterns in the data (i.e., measurements of characters) and relationships between "operational taxonomic units" (OTUs, specimens in this study) , without a priori subdivision of OTUs into discrete groups. The characters are unweighted. The results, 99 100 complex "scatter diagrams" used in evaluating the phenetic gaps between the OTUs, are produced from the ordination of the OTUs along generated axes ("principal components") . These principal components (axes) are actually representations of the characters, each of which vary in their relative contribution ("factor loading") to each PC axis. Each principal component represents a percentage (per cent of trace) of the total variation between the OTUs. A higher eigenvalue indicates that more variance is accounted for by that particular principal component. Usually, only the first two or three principal components, which have the highest eigenvalues and typically encompass most of the variation, are used for the graphs. The principal component analysis also produces an index of highly correlated (and possibly redundant) characters in a correlation matrix. Highly correlated characters may then be reevaluated and perhaps deleted. Care must be taken with each step of the process, including selection of appropriate OTUs and characters (discussed below) . Choice of OTUs and Choice of Specimens The operational taxonomic unit in this study is defined as all specimens of a particular collector's collection number (one "record" or collection) . Since many bryophyte collections were distributed as exsiccatae, duplicates have been deposited at many institutions, resulting in a wealth of material for many collections. Each collection number represents a sample of a natural population, and often even 101 within one packet, individual plants are not easily discernible. As stated in the introduction, approximately 2,400 specimens were received on loan for this study. After taking into account duplicates and deleting those specimens misidentified as Rjqodium, the data base contained a total of 1240 records. Of these, 50 were designated "Anonymous s.n.," usually with fragmentary material and little or no label data (country, location, etc.), and thus not suitable for inclusion in the phenetic study. It was not uncommon for moss collections to be split up, and incompletely copied label data accompanied the derivative specimens to their new institutions. About 300 more specimens with complete label data (but with missing collection numbers) were probable duplicates of other specimens: the collectors, dates, and localities exactly matched other specimens with collection numbers. Taking these into account, a total of 890 more or less suitable OTUs ("records" or collections) were available from which to chose a sample set representing the variation within the genus. These specimens seemed to adeguately represent the variation in the genus over its geographical range as described in the literature. For example, most (ca 660) of these 890 records were from Chile (560 specimens) and Argentina (100 specimens) , apparently the area of greatest variation due to the number of epithets associated with these areas (see Table 1) . Of note are the approximately 102 120 Chilean specimens from the well-collected Juan Fernandez Islands. The over-representation of this area within the 890 specimen pool was taken into account when specimens were selected. Starting with localities in Hispaniola and Central America and working southward, specimens were carefully examined to cull the sample set to be used in the phenetic analysis. Besides geography, the specimens were evaluated on the basis of variation in characters, quality and abundance of material, ecology, and presence of sporophytes. A total of 140 specimens were initially chosen for the sample set. After much closer examination of these, 12 0 (approximately 14% out of the original 890) eventually were evaluated for the phenetic analysis and are listed in Appendix A. Fifty-two of these had mature sporophytes (seta plus at least the capsule urn with peristome teeth) . This method of non-random selection may have actually biased the sample set towards increased variability in comparison to a traditional typologically based study where variability often tends to be ignored (e.g., the methodology espoused by Frahm, 1989) . The choice of specimens for this study was thus not influenced by typological preconceptions (i.e., not with a priori grouping as in Stark, 1987). Type specimens were included only to demonstrate that most of the epithets were redundant (type OTUs scattered throughout the variation of the group) and to assign the oldest epithets in 103 naming groupings of the PCA (but see also discussion of phylogeny) . Choice of Characters The particular morphological characters measured for the phenetic study were selected on the basis of observation in variation of numerous features in a detailed preliminary study of 4 0 specimens. Several of the types were included at this stage in order to gain a perspective on the historical importance of some characters mentioned in the literature. Table 6 lists the characters used in the PC analyses depicted in Figs. 24 and 25. Thirty-six of these characters are gametophytic and 11 are sporophytic. Missing data (perichaetial leaves and sporophytes) were accommodated by the NTSYS-pc software program. Five measurements were obtained for each character on an OTU, except for some sporophytic features for which material was lacking. Five samples (measurements) of each character per OTU were determined to be the minimum number sufficient to obtain a mean which adequately estimates the actual mean (measurements of that character) for an OTU. This was ascertained by the mathematical relationship between sample size (n) and the 95% confidence interval for the actual mean of a given OTU (u) shown in the statistical correlations presented in Appendix B. The general techniques involved in specimen preparation and mensuration are described in the previous section on general materials and methods. Equivalent structures were 104 measured on each specimen (Fig. 23), and the scheme of measuring each character was also standardized. As an index of the habit form and size, the stem width and the stipe, stem, and longest primary branch lengths were included. The stem width was measured from a cross section taken from the midpoint of the stem (Fig. 2 3B) . The stipe leaves were removed at mid-stipe (Fig. 23C) because the leaves here typically had well-developed acumens (in comparison to the leaves below with usually shorter acumens) and were ecostate (in comparison to the leaves above where traces of the costa first appear) . In plants with a poorly developed stipe (i.e., non-arborescent habit), the stipe leaves were also taken from the middle of the basal portion of the stem before it branched, and here the leaves were found to be ecostate, as well. The stem leaves were taken consistently from the mid-stem (Fig. 23D) . The branch leaves were from the secondary branches (Fig. 231) , as those of the primary branches were often transitional forms (Figs. 7K-L, 8K-L) . Costa width was measured at the base (at its maximum) . The first five complete leaves (stipe, stem, branch, and perichaetial) encountered in scanning each slide were measured. A representative stem leaf was chosen for the measurements for five each of the alar, marginal, intramarginal, and midlaminar cells at the locations indicated in Fig. 23D-H. The marginal, intramarginal and laminar cell measurements were included as an attempt to guantify the leaf "border" mentioned under the morphology 105 section. The longest (inner) post-fertilization perichaetial leaves were measured (Fig. 23J) . Although the sporophytic characters appeared to be more or less consistent among the OTUs, they were included in the PC analyses to see if any subtle differences could be detected Fig. 2 3K-M) . Results of the Principal Component Analyses As emphasized by Wiley (1981) , PCA is not really a clustering technique designed to discriminate between groups, but it can aid in distinguishing between groups not readily apparent in the original data. The best results of several PC analyses are presented in Figs. 24 and 25. The first analysis (Fig. 24) included all 120 OTUs (listed in Appendix A) , and the second (Fig. 25) , the 85 OTUs of the R. toxarion var. toxarion and R. brachvoodium var. brachypodium complexes (indicated with asterisks in the list in Appendix A) . In the graphs, the OTUs are labelled (with the outlying points connected) according to the final species determination in this monograph (see phylogeny) . The type specimens are indicated by numbers as listed in Appendix A. The characters that most influence (i.e., have the highest eigenvalues) each principal component (axis) are listed along the appropriate axes. Of note is PC 3 of the second analysis (Fig. 25B) in which only features of the sporophyte (seven characters) had high factor loadings. All ordinations show some overlap of OTU complexes, reflecting the sometimes subtle differences between the five 106 recognized species. In addition, the actual separation of species in these plots may not be adequately depicted since each graph represents only approximately 32 to 41% of the total variation. Finally, some distinctive qualitative characters have not been included in the data. For example, the most distinctive group, R. pseudo- thuidium (including R. hvlocomioides) , separates best along PC 2 in Fig. 24A due to the ecostate stem leaves (and to a lesser extent, along PC 1 due to an unusual habit) . The R. implexum OTUs, although consistently overlapping within the R. brachvpodium complex, generally form a relatively tight group. Riaodium implexum is primarily characterized by an unusual habit probably not well-revealed in these analyses. The new species, R. adpjressum, is also characterized by some qualitative features, such as centralized, dorsal papillae in the decurrent portion of the leaf and the extremely thick walls of the intramarginal cells. The overlap between R. adpressum and R. brachvpodium and R. toxarion reflects the similar habit of the three species. Also the stipe and stem leaf shape of R. adpressum is more or less intermediate between that of R. brachvpodium and R. toxarion (Zomlefer, 1992) . The large and extremely variable R. toxarion and R. brachvpodium clusters show some overlap in all scatter diagrams, even in Fig. 25 where the the OTUs of the other three species were deleted. This analysis supports the hypothesis of R. brachvpodium (OTU number 5) and R. 107 arborescens (OTU number 3) as belonging to the same entity, phenetically close to the R. toxarion complex. Characters of PC 1 (habit type, stipe and stem leaf size and shape, intramarginal and midlaminar cell size and shape) best separate these two complexes. The variable specimens of the R. toxarion cluster include the types for 15 species, with 13 from Central and South America (see Table 1) . The intermixing of the African OTUs ("R. kilimandscharicum" of continental Africa and "R. niveum" of Madagascar) within R. toxarion proper (Central and South America) in both analyses indicates that these African "species" are conspecific and express the genetic variation shown in the group in general in the New World. Of note is that measurements of the various cell types (characters 19-30) tended to be highly correlated, as did the sporophytic features (37-47) . In summary, the PC analyses generally support the five species of Rigodium presented in this monograph. R. pseudo- thuidium is the most distinctive due to the habit (little branched) and ecostate upper stem leaves. R. imolexum and R. adpressum are best characterized by qualitative features discussed above and under their respective descriptions which follow. R. brachvpodiiiTit (including R. arborescens) is best distinguished from R. toxarion on the basis of leaf characters, including the size and shape of the intramarginal and midlaminar cells. The scatter diagrams generally depict the inclusion of the types of 15 species 108 (including 2 from Africa) within R. toxarion. The concept of a more variable R. toxarion thus has a disjunct distribution (Central/South America and Africa) , expanded from the original restricted range of Hispaniola and Central America. 109 Table 6. Characters used in the phenetic analyses of Rigodium. 1. stipe length 2 . stem length 3 . longest primary branch length 4. stem width 5. stipe leaf length (from point of insertion) 6. stipe leaf width 7. stipe leaf acumen length 8. stipe leaf length/width 9. stipe leaf acumen length/leaf length 10. stem leaf length (from point of insertion) 11. stem leaf width 12. stem leaf acumen length 13. stem leaf length/width 14. stem leaf acumen length/leaf length 15. stem leaf decurrency length 16. stem leaf decurrency length/total leaf length 17. costa length 18. costa width at base 19. alar cell length 20. alar cell width 21. alar cell length/width 22. marginal cell length 23. marginal cell width 24. marginal cell length/width 25. intramarginal cell length 110 Table 6 — continued 26. intramarginal cell width 27. intramarginal cell length/width 28. midlaminar cell length 29. midlaminar cell width 30. midlaminar cell length/width 31. branch leaf length (from point of insertion) 32. branch leaf width 33. branch leaf length/width 34. perichaetial leaf length 35. perichaetial leaf width 36. perichaetial leaf acumen length 37. seta length 38. capsule urn length 39. capsule urn width 40. operculum length 41. capsule mouth width 42. beak length 43. exostome tooth length 44. exostome tooth width 45. endostome tooth length 46. basal membrane height 47. cilia length FIG. 23. Morphological Features Measured for PC Analyses. A. Habit. B. Cross section of stem. C. Stipe leaf. D. Stem leaf. E. Alar cell. F. Marginal cell. G. Intramarginal cell. H. Midlaminar cell. I. Secondary branch leaf. J. Perichaetial leaf. K. Sporophyte. L. Capsule. M. Portion of peristome. A-L from Tonduz fPittier No: ] 5667 (BR, R. toxarion) ; M from Matteri & Schiavone 4985 (Herb. Matteri, R. adpressum) . See Table 6 for numbered character list. 112 0.3mm FIG. 24. Plots of the First Three Principal Components for Phenetic Analysis of all Riqodium Species. A. PC 1 vs. PC 2 . B. PC 1 vs. PC 3. Numbered points correspond to type material listed in Appendix A. 114 0.50- 0.25- 2 -0.25 C -0.50 O -0.75- -1.00- O R. toxarion var. toxarion (SA): B (Afr): ■ var. robustum OR. brachypodium var. brachypodium;# var. tamarix ▲ R. paeudo- thuidium A R. implexum T R. adpressum -1.00 -0.75 -0.50 -0.25 0 0.25 0.50 0.75 1.00 PC 1 (21%) (habit, stipe and stem leaves, intramarginal cells, branch leaf) B > £ C o ■ a 0.75 0.50 0.25 CO o Q. -0.25- -0.50- -1.00 -0.75 -0.50 -0:25 0 0.25 0.50 0.75 1.00 PC 1 (21%) (habit, stipe and stem leaves, intramarginal cells, branch leaf) FIG. 25. Plots of the First Three Principal Components for Phenetic Analysis for R. toxarion var. toxarion and R. brachypodium var. brachypodium . A. PC 1 vs. PC 2 . B. PC 1 vs. PC 3. Numbered points correspond to type material listed in Appendix A. 116 A o 75 a o a. 0.50 0.25 C -0.25- CM o Q. -0.50- -0.75 -1.00 -0.75 -0.50 -0.25 0 0.25 0.50 0.75 1.00 PC 1 (27%) (habit, stipe and stem leaves, intramarginal and midlaminar cells) B c Q. O o a. » 0.75- 0.50 0.25- «-* 0 00 CO o Q. -0.25 -0.50 DR. toxarion var. toxarion (SA); E3 (Afr) O B- brachypodium var. brachypodium -1.00 -0.75 -0.50 -0.25 0 0.25 0.50 0.75 1.00 PC 1 (27%) (habit, stipe and stem leaves, intramarginal and midlaminar cells) PHYTOGEOGRAPHY The distribution of Rigodium (Fig. 26) consists of four endemic austral South American species (R. brachvpodium. R. adpressum. R. implexum, and R. pseudo-thuidium ; Figs. 37, 42, 45, and 48, respectively) and a single species disjunct between South America and Africa (R. toxarion; Fig. 30) . The disjunct R. toxarion has a much more widespread neotropical range than the other four species, which are generally restricted to the Andean Cordillera in southern Chile and Argentina. The range of R. toxarion includes Hispaniola and the Central American Cordillera, as well as the Andean Cordillera through Bolivia, Ecuador, and Peru to Chile. Rigodium toxarion occurs also in the highlands of Venezuela and Colombia and along the coastal ranges (Serra do Mar and Serra do Espinhago) of southeastern Brazil, but has been collected only in the highlands near Tucuman in Argentina. In southeast Africa, R. toxarion is restricted to the elevated ranges from just south of the eguator to the tip of Africa; the species occurs also at one locality in northern Madagascar. This type of disjunct South American-southeastern African distribution pattern has been noted for several genera of bryophytes (see Griffin et al. , 1982; Gradstein et al., 1989). Two basic theories, discussed in detail in 117 118 Gradstein et al. (1983) , have been espoused as explanations for intercontinental disjunctions among bryophytes. Some bryologists (e.g., Schuster, 1983) advocate long-distance dispersal, while others (e.g., Buck and Griffin, 1984) emphasize continental drift as the primary factor. Rigodium has a range similar to that of Squamidium brasilienser discussed by Allen and Crosby (1986) . The authors follow Schuster's (1983) assumption that conditions for wind dispersal are extremely plausible, considering the proximity of the continents and the latitudinal range of strong westerlies. However, in their overview of bryophytes with South America-African distribution, Buck and Griffin (1984) conclude that long-distance dispersal is unlikely as the sole agent considering the taxonomic, distributional, and ecological diversity of those disjuncts. Further, spore survival studies by van Zanten (1976, 1983, 1984; & Pocs, 1981) indicate that tropical bryophyte spores are less likely than those of temperate species to survive the rigors of intercontinental long-distance dispersal due to their greater sensitivity to desiccation and dry-freezing. In addition, the spores of mosses from mesic habitats (e.g., Rigodium) tend to have little resistance to extended periods of desiccation, and pleurocarpous mosses are less drought resistant than acrocarps. Van Zanten (1983) concludes that such transoceanic transport across the equator via dry air- streams, in general, is difficult. 119 The fact that the distribution of Rigodium in Africa is restricted to the southeastern portion of the continent indicates that the genus may not be able to cross even moderate sized barriers: Rigodium is not found in montane western Africa, although suitable, high altitude habitats exist there (e.g., in Cameroon; Griffin, per. comm.). Continental drift and the effects of the Pleistocene glaciation may thus be the reasons for the extant disjunct range, possibly representing a relict distribution from one originally widespread in Gondwanaland during the Mesozoic. Increasing aridity may have caused the subseguent extinction fo the genus in western Africa. The center of diversity, where all five species occur, is in the Andean Cordillera along the Chilean-Argentinian border in central Chile. As discussed above, the most ancestral species, R. toxarion. has a disjunct and a more tropical distribution (to ca 45°S) , and the four derived species evidently are better adapted for temperate latitudes (to 55°S). This may indicate that Rigodium radiated (and subseguently speciated) from the northern latitudes southwards throughout South America. Speculation about the original ranges of the other four species is not possible: they are all basically sympatric and have probably spread along the Andean Cordillera to the tip of South America by "short-distance" dispersal. FIG. 26. Distribution of the Genus Riqodium. 121 105° 90° 75° 60° 45° 30° 15 30° ■ WW ww 1 \J wU v Y ^ 16* Vi^^-*-- 0°- 15°- 1 i /~y / •«—■<, '--) 30°- 45' 60oj-t r Distribution of Rigodium ' r ■45° v/i •fc* 105° 90° 75' 609 45° 30° 15 T r 15° 30° 45° TAXONOMIC TREATMENT Rigodium Kunze ex Schwagr., Linnaea 18: 559. 1844 [1845]. Type: R. implexum Kunze ex Schwagr. Hypnum Hedw. section Rigodium (Schwagr.) C. Mull., Syn. 2: 418. 1851. Plants predominantly medium-sized to moderately robust, wiry, dendroid, frondose, to rarely subsimple, erect, pendent, or creeping, irregularly to + regularly pinnately branched, sometimes highly branched and forming unattached mats, occasionally rooting at tips of stems and primary branches, green, yellow-green to yellowish brown or brownish green, on tree trunks and branches or occasionally on logs, soil or rocks. Rhizoids red-brown, smooth, with oblique end walls, occurring on substrate sides of stolons and stems, sometimes clustered at tips of stems and primary branches. Stolons reddish brown to brown, creeping and adnate to substrate, often with + less-developed leaves than the rest of the plant; in cross-section with an outer rind of (3-)4- 5 (-6) rows of small, incrassate cells and an inner cortex of larger, thin-walled cells surrounding a central strand of (6-) 10-20 (-50) very small, thin-walled cells. Main axes in cross-section similar to stolon, often differentiated into unbranched, reddish-brown stipe and branched stem; surface 122 123 furrowed. Branches widespread to closely spaced on stems, curved or straight, sometimes flagellate. Axillary hairs abundant in leaf axils at stem and branch tips, 57-72 urn long, consisting of 3 cells per hair; basal cells 2, square, pigmented (lower one sometimes lightly pigmented) ; terminal cell elongate, rounded at apex, hyaline. Paraphyllia none. Pseudoparaphyllia none. Leaves trimorphic (stipe, stem and branch) or sometimes dimorphic; cells incrassate throughout, + porose with even to usually uneven walls at base and midlaminar regions, prorulose, rounded-quadrate (base and margins) to oblong, rhombic or rhomboidal (upper and midlaminar regions) , 3-10 ± larger, thicker-walled cells commonly forming intramarginal band of cells; alar regions not differentiated. Stem leaves commonly crowded on stems, broadly ovate-cordate at base and abruptly narrowed to a well-developed acumen, sometimes subulate, usually wide- spreading to squarrose (+ spreading to appressed in R. adores sum) , with clasping and concave bases, sometimes longitudinally undulate, sometimes auriculate, sometimes decurrent (then occasionally some cells of decurrent portions with central papilla on the dorsal side) ; margins erect to plane to more commonly reflexed to revolute, serrulate to dentate above and serrulate, dentate to sometimes crenulate at base; costa present and well- developed (occasionally weak to absent) , ending in the base of acumen, with an A-type cross-section (see Kawai, 1968), 2-5-stratose in the lower half, rugose on dorsal surface. 124 Stipe leaves with similar shape, orientation and areolation as stem leaves, often widespread on axis; costa absent or rarely present and then very weak or double. Branch leaves broadly to narrowly ovate, acute to slightly acuminate, erect to spreading; margins serrate or serrulate to base; costa single, usually well-developed, strongly bulging abaxially, 2-3-stratose in the lower half, ending below leaf apex. Dioicous; antheridial and archegonial plants identical, archegonial plants more commonly found. Perigonia small and bud-like, lateral, mostly along primary branches but also along stems and secondary branches. Pericfonial leaves ovate, acute to shortly acuminate, concave; margins entire at base and serrulate above; costa absent; cells oblong to rhombic below and becoming shorter above. Antheridia commonly (3-) 4 per perigonium, subcylindric, orange or tinged with orange; paraphyses 6-12 cells long, surpassing the antheridia, composed distally of hyaline rectangular cells and commonly with 2 quadrate, thinner-walled, pigmented cells at base. Perichaetia lateral, mostly along stems but also along primary branches. Perichaetial leaves subulate from a narrowly obovate sheathing base, keeled in the lower half, concave, often with whitish or orange-tinged base, with spreading to squarrose tips; costa absent to very weak; margins + entire, sinuous to denticulate near base and deeply serrate above; cells oblong to rhombic at base and becoming shorter and flexuous above, porose at base, with basal cells frequently 125 papillose (bearing one large central papilla on the dorsal side) , prorulose. Archegonia numerous per perichaetium; paraphyses 9-19 cells long, surpassing the archegonia, composed distally of hyaline rectangular cells and commonly with 2 (-4) quadrate, thinner-walled, pigmented cells at base. Sporophvtes infrequent. Seta elongate, reddish, smooth. Capsules exserted, horizontal to inclined, asymmetric, cylindric; exothecial cells incrassate throughout, irregularly hexagonal-rhombic at mouth, rhombic at mid-urn, linear at neck. Stomata few at base of urn, elevated, superficial (phaneroporous) , often heavily pigmented, surrounded by (7-) 8 (-10) subsidiary cells. Annulus deciduous, consisting of 2 rows of rectangular incrassate cells. Operculum short- to long-rostrate. Peristome double. Exostome teeth 16, yellow-orange, inflexed when wet and reflexed when dry, linear-lanceolate, gradually tapered, cross-striolate below and papillose above on the front surface, with zig-zag median line, bordered, weakly trabeculate on front, strongly trabeculate at back. Endostome segments 16, arising from well-developed basal membrane, linear-lanceolate, gradually tapered, keeled, perforate, as long as or shorter than teeth, finely papillose; cilia (l)-2-3, nodose, papillose. Spores spherical, papillose. Calvptra cucullate, smooth, naked. Key to the Species of Rjgodium The bases of Rjgodium stem and stipe leaves encircle and tightly clasp the axes. Care must be taken to remove 126 the entire leaf from the stem, including the decurrent basal portions when present (Fig. 9C) . Several leaves should be examined in order to adequately sample the range of variation within a specimen. "Stem leaves" are defined as those from the middle to lower half of the stem, i.e., through the branched portion of the main axis (Figs. 7F, 8F) . The "intramarginal band of cells" (Fig. 12) is best discerned under low power. 1. Plants extremely wiry and profusely branched with secondary and tertiary branches at wide angles to the stems, often terrestrial and typically forming large, tangled, stiff, unattached mats ("tumbleweeds") ; costa of stem leaves very well-developed (4- to 5-stratose in lower half). 4. R. implexum. 1. Plants somewhat stiff to lax without branching pattern as described above, attached to substrate; costa of stem leaves 2- to 3-stratose or absent. 2 . Stem and stipe leaves closely appressed to stem (tips slightly spreading when wet) , with prominent, elongate, decurrent, auriculate projection at base containing at least a few cells with a single central "papilla;" intramarginal border very well- differentiated with 5-6 rows of cells with much thicker walls and much shorter and wider lumens than those of the median cells. 3. R. adoressum. 127 2 . Stem and stipe leaves strongly spreading to sguarrose wet or dry, + auriculate but without well- developed elongate auriculae as above; intramarginal border weak to strong (and when well -developed, usually of cells with longer and wider lumens than those of the median cells) . 3. Acumen of stem leaves very long, at least one half of the total length of the leaf. 4. Intramarginal border strong, of 3-5 rows of larger cells; median cells distinctly prorulose and occasionally with end walls projecting prominently as well-developed papillae (prorulae) on the dorsal surface; plants with long straggling stems and widely-spaced, + regularly pinnately- branched primary branches. 2b. R. brachypodium var. tamarix. 4. Intramarginal border weak to slightly developed; median cells ± prorulose (not projecting dorsally as prominent papillae) ; habit various but usually arborescent or stems lax and subsimple to irregularly branched. la. R. toxarion var. toxarion. 3. Acumen of stem leaves shorter, less than one half of the total length of the leaf. 128 5. Intramarginal border not well- differentiated (intramarginal cells intergrading with median cells) ; leaf cells + prorulose; median cell walls evenly thickened; acumen of stem leaves generally greater than 2/5 of the total leaf length. 6. Secondary branch leaves ovate, less than 2 1/4 times as long as wide. la. R. toxarion var. toxarion. 6. Branch leaves lanceolate to narrowly ovate, at least 2 1/4 times as long as wide; (Juan Fernandez Islands endemic) . lb. R. toxarion var. robustum. 5. Intramarginal border well-differentiated with (4) -6- (9) rows of cells with much thicker walls and larger lumens than those of the median cells; leaf cells prorulose; median cell walls unevenly thickened; acumen of stem leaves generally less than 2/5 of the total leaf length. 7. Habit arborescent with clearly differentiated stipe, stem, and branch system; primary branches closely spaced on stem; costa of 129 stem leaves well-developed; median leaf cells extremely prorulose with the end walls occasionally projecting as well- developed papillae (prorulae) . 2b. R. brachypodium var. brachypodium. Habit without clearly differentiated stipe and stem, usually with very little secondary and essentially no tertiary branching; primary branches widespread and remote; stem leaves often ecostate or with a short, double or weak costa; median leaf cells prorulose without dorsally projecting papillae. 5. R. pseudo-thuidium . 130 1. Rigodium toxarion (Schwagr.) Jaea. Hypnum toxarion Schwagr., Spec. Mus. Supp. 1(2): 283. 1816. Rigodium toxarion (Schwagr.) Jaeg. , Ber. S. Gall. Naturw. Ges. 1876-77: 244. 1878 (Ad. 2: 310). Type: Hispaniola. Insula St. Domingo [Dominican Republic?], no date, Anonymous s.n. (lectotype here designated [probable holotype] : G!). The original citation of Schwagrichen (1816) has little identifying information. Only one specimen from Hedwig's (Schwagrichen1 s) herbarium at G is from "St. Domingo" (labelled as "Hypnum toxarion") and is likely original material, if not the holotype itself. However, a conservative approach is followed here as espoused by Ortiz (1989) and discussed in Zomlefer (1991) in avoiding the term "holotype" in instances of uncertainty; "lectotype" is therefore used in this situation. Hypnum solutum Tayl., London J. Bot. 5: 65. 1846. Riqodium solutum (Tayl.) Par., Ind. Brvol . 1140. 1898. Types: Ecuador. Imbabura: Ridge of Pisagua, near Otovalo, 10,000 feet [3000 m] , 1827, Dr. Greville's Herbarium, Jameson s.n. (lectotype: FHl); Trees on ridge of Pisagua, 1827, Jameson s.n. (probable isolectotype: E!); lectotypification in Zomlefer (1991). Hypnum argentinicum C. Mull., Linnaea 43: 480. 1882. Rigodium argentinicum (C. Mull.) Kindb., Enum. Brvin. Exot. 103. 1891. Type: Argentina. Tucuman: 131 Tucamensis [Tucuman] prope Juntas, 1872, Lorentz s.n. (lectotype, BM! : possible isolectotype as s.n. with no date: NY!); lectotypif ication in Zomlefer (1991). Rigodium qracile Ren. & Card., Bull. Soc. R. Bot. Belq. 32(1): 197. 1894. Types: Costa Rica. San Jose/Cartago: Forets du Volcan Irazu, 10 Jul 1891, Tonduz fPittier No: ] 5666 (lectotype here designated: PC!; isolectotypes: BR (2 specimens)!, G! , NY!); Forets de l'Irazu, 1891, Tonduz fPittier No: ] 5666-5667 (syntypes: H! , S!,); Forets de l'Irazu, 10 Jul 1891, Tonduz TPittier No: 1 5667 (syntypes: BR (2 specimens)!, PC!); San Jose: Forets du Barba, 2700-2800 m, 6 Feb 1890, Biollev TPittier No: 1 5668 (syntypes: BR!, PC!); Puntarenas: Forets a General [General], 1891, Tonduz fPittier No: 1 5725 (syntypes: NY!, PC!). With the original description, Renauld and Cardot (1894) cited several specimens associated with Pittier plus collection numbers, giving the impression that Pittier himself collected all of these types. Examination of the labels on the specimens clearly reveals that Pittier assigned his own numbers to these unnumbered collections of Tonduz (Pittier1 s assistant; see Sayre, 1975) and Biolley as indicated above. Hypnum kilimandscharicum Broth., Bot. Jahrb. 24: 280. 1897. Rigodium kil iroandschar icum (Broth.) Par., Ind. Bryol . 1140. 1897 [1900]. Types: Tanzania. Kilimanjaro: 132 Kilimanscharo, Wald bei Marangu, iinterer Giirtelwald, an Baumen, 2100 m, 13 Jun 1894, Volkens 2349 (lectotype here designated: H-BR! ; isolectotypes: JE!, S!; possible isolectotype as s.n., M!). Rigodium leptodendron C. Mull., Nuovo Giorn. Bot. Ital. n. ser. 4: 158. 1897. Types: Bolivia. Cochabomba: Prope Choquecamata , Jun 1889, Germain [Muller No: ] 1166 (lectotype here designated: NY!; isolectotypes: G!, H- BR! , JE! , M! , S!) . Rigodium hamirameum C. Mull., Hedwigia 40: 81. 1901. Types: Brazil. Santa Catarina: Serra Geral, am Wasserfall des Capivare, Jan 1890, Ule 892 (lectotype here designated: M! ; isolectotype: H-BR!). Rigodium pertenue C. Hull., Hedwigia 40: 81. 1901. Types: Brazil. Rio De Janeiro: Serra do Itatiaia [Itatiaya], an Felsen der Agulhas Negras [Pico das Agulhas Negras] , 2500 m, Dec 1895, Ule 2135 (lectotype here designated: M! ; isolectotypes: FH! , H-BR!). Rigodium araucarieti C. Mull., Hedwigia 40: 82. 1901. Types: Brazil. Santa Catarina: Serra Geral, auf dem Boden der Araucarienwalden, Apr 1889, Ule 524 (lectotype: H-BR!); ad lapides, May 1890, Ule 677 (syntype: specimen not seen; possible syntype as s.n.: FH!); lectotypification in Zomlefer (1991). 133 Rigodium araucarieti var. catenulatum C. Mull., Hedwigia 40: 82. 1901. Types: Brazil. Rio Grande do Sul : Ex- colonia Pto. Angelo, ad truncos putrescentes terrae incumbentes silva primavae, 1893, Lindman 176 (lectotype: H-BR! ; isolectotypes as B176: S (2 specimens)!, UPS!; probable isolectotype as s.n.: S!); Forromecco [Forromeco] , 1888, Kunert s.n. (probable syntype: KRAM!); lectotypif ication in Zomlefer (1991). Rigodium niveum Ther. , Recueil Publ. Soc. Havraise Etud. Diy. 1925: 144. Unnumbered plate, Figs. 1-7. 1925. Type: Madagascar. Mt. Tsaratanana [or Mt. Madagascar], 1200-2400 m, Apr 1924, Perrier de la Bathie 168 (lectotype here designated: PC!; probable isolectotypes as s.n.: S (2 specimens)!). Although Theriot (1925) did not specify a collection number for Perrier de la Bathie* s collection, the label data of Perrier de la Bathie 168 (from Theriot' s herbarium at PC) matches the date and elevation of Theriot *s citation. Additionally, the specimen is labelled as "Rigodium niveum Ther. sp_. nov . " Rigodium nano-fasciculatum C. Hull, ex Ther., Rev. Brvol . n. ser. 2: 232. 1929 [1930]. Types: Chile. Concepcion: Isla Quirigunda [Guiriquina] in truncis arborum/putridis, 2 0 Sep 1896, Dusen 225 (lectotype: PC!; isolectotypes: BM! , FH! , FLAS ! , GB! , H-BR!, JE! , M!, MICH!, NY!, O! , S!, W! ; possible isolectotype as 134 (225) A29: NY!; Chile. Malleco: Victoria, Mar 1916, Campo 10B p.. p.. (original material: PC!); lectotypification in Zomlefer (1991) . Rigodium pendulum Herz . & Ther. in Herz. et al., Beih. Bot. Centralbl. 60: 31. 1939. Types: Chile. Chiloe: Westpatagonien, Puyuhuapi [Puerto Puyuguapi], Waldhagen, am Rand des Talsumpfes an Arayanstammen, 9 Feb 1938, Schwabe 79/b2 (lectotype: JE!; isolectotypes: JE!, PC!; Schwabe 79/bl (syntypes: JE (2 specimens)!); lectotypification in Zomlefer (1991) . Rigodium pallidum Sehnem, Pesquisas. Bot. 30: 38. Plate XIID. 1976. Type: Brazil. Rio Grande De Sul : Sao Francisco de Paula, Taimbe, ad arborum, 900 m, 26 Feb 1959, Sehnem 7367 (holotype: PACA! ) . Index Muscorum Supplementum: 1976-1977 (Crosby, 1979) lists the location of the holotype as unknown. The single specimen at PACA is clearly indicated as "holotype" on the label by the author. No duplicates (isotypes) are known to be deposited elsewhere (Ronaldo Wasum, pers. comm. ) . Plants small to large, dendroid or occasionally subsimple, erect, pendent, or sometimes creeping, irregularly pinnately branched, on tree trunks and branches or occasionally on logs, rocks, or soil, green to yellow- green, sometimes rooting at tips of stems and primary 135 branches. Stipes well-developed, to 2.5 cm long. Stems to 4. 5 (-12.0) cm long, 215-530 um in diameter. Primary branches generally 10-25 (-60) per stem, spaced 1.0-3.0 mm apart along the stem, proximal ones to 2.9 cm long, gradually becoming much shorter above, sometimes attenuate (and then often rooting at tips) . Secondary branches generally 5-25 per primary branch, to 1.0 cm long. Tertiary branches present. Stem leaves ovate at base and abruptly narrowed to a well-developed + long acumen, subulate, 0.47- 1.67 x 0.31-1.57 mm, generally much longer than wide with length/width ratio (1. 00-) 1. 31 (-1. 74) , spreading to squarrose, with clasping and concave base, rarely auriculate, barely decurrent with decurrent portion 0.03- 0.08 mm long (3-8% of total leaf length); acumen 0.30-0.98 mm long, (38-) 50 (-60) % of leaf length measured from point of insertion; margins erect to plane or narrowly reflexed, + entire, sinuous, crenulate, to serrate at base and serrate above; costa single, well-developed but relatively slender, 0.27-1.18 mm long, 17-56 (-70) um wide at base, 2-3-stratose in lower half; alar cells quadrate to oblate, 6.6-11.9 x 6.4-12.1 um; marginal cells 1-2-seriate, oblong-rhombic, 8.1-17.2 x 3.3-6.2 um; intramarginal cells 3-4 (-5) -seriate, oblong, 8.9-21.5 x 5.0-9.1 um, with ± thicker walls than the midlaminar cells and forming a very weak intramarginal band; midlaminar cells oblong to rhombic or rhomboidal, 13.0-27.6 x 3.8-7.3 um, with even walls, weakly prorulose. Stipe leaves with similar shape and orientation as stem leaves, 136 0.52-1.27 x 0.20-1.00 mm; acumen 0.22-0.70 mm long; costa absent or rarely present and then very weak. Secondary branch leaves narrowly ovate, acute, 0.28-1.33 x 0.14-0.49 mm, with length/width ratio (1. 48-) 2 .00 (-3 . 12) , erect- spreading to spreading; margins serrate. Periaonial leaves ovate, acute to shortly acuminate, 0.57-1.04 x 0.27-0.41 mm. Antheridia 300-390 x 75-125 urn; paraphyses 6-12 cells long, 300-510 um long. Perichaetial leaves subulate, 1.10-3.35 x 0.36-0.98 mm, long-acuminate with acumens 0.33-0.80 mm long; basal cells rhomboidal, 26.0-60.7 x 7.7-14.0 um, weakly prorulose, sometimes papillose with one large central papilla; apical cells rhombic, ± sinuous, 17.3-30.6 x 2.0- 7.7 um. Archeaonia 310-550 um long, 35-50 wide at venter; paraphyses 10-23 cells long, 375-830 um. Seta to 3.0 cm long. Capsule urn 1.23-1.73 x 0.40-0.67 mm; upper exothecial cells 16.3-25.0 x 14.3-25.0 um; median exothecial cells 41.7-70.0 x 21.0-32.3; cells in neck 25.0-56.7 x 10.7- 21.0. Operculum 0.40-0.70 mm long, long-rostrate with beak 0.25-0.63 mm long. Exostome teeth 463-730 um long, 88-120 um wide at base. Endostome segments 180-465 um long, 40-65 um wide at base; basal membrane 150-290 um high; cilia (1- )2(-3), 180-465 um long. Spores 16-24 um in diameter. Calyptra to 3.1 mm long. la. Rigodium toxarion (Schwagr.) Jaeg. var. toxarion Plants small to large, dendroid or occasionally subsimple, erect, pendent or sometimes creeping. Stipes to 2.5 cm long. Stems to 3. 7 (-12.0) cm long, 215-530 um in 137 diameter. Stem leaves ovate at base and abruptly narrowed to a well-developed long acumen, subulate, 0.47-1.67 x 0.31- 1.06 mm, generally much longer than wide with length/width ratio (1.00-) 1.30(-1.74) ; acumen 0.30-0.98 mm long, (38- )50(-60)% of leaf length measured from point of insertion. Secondary branch leaves narrowly ovate, 0.28-0.55 x 0.14- 0.34 mm, with length/width ratio (1. 48-) 1. 95 (-2 .21) . Representative specimens examined. CENTRAL AND SOUTH AMERICA. ARGENTINA. TUCUMAN: Argentina subtropica Tucamensis [Tucuman] prope Juntas, 1873, Lorentz s.n. (S, W). BOLIVIA. AYOPAYA: Depto. Cochabamba, Sailapata, wet forest, epiphyte, 2700m, Nov 1935, Gardenas 3229 (NY). INQUISIVI: Depto. La Paz, 2 km above Quime, 67°14'W, 16059'S, transitional area between humid and semi-humid forests, stone at base of cliffs in shady ravine forest, 3380m, 1987, Lewis 87-978 (LPB) . SANTA CRUZ: In Nebenwald iiber Comarapa, 2600m, Mar 1911, Herzoa 3817 (FH, H, JE, L, M, NY, 0, S, W) . BRAZIL. ESPIRITO SANTO: Domingos Martins, Reserva Forestal Pedra Azul , 20°25'S, 41°01,W, 1180m, 9 Oct 1988, Schafer-Verwimp & Verwimp 10111 (NY) . PARANA: Balsa Nova, in truncis putridis, 28 Jul 1909, Dusen 8496 (GB, S) . RIO DE JANEIRO: Serra do Itatiaia [Pico das Agulhas Negras] , 2200m, Jun 1902, Dusen 461 (S) . RIO GRANDE DO SUL: Gramado, ad lignum siccum in silva, 800m, 27 Dec 1949, Sehnem 4686 (FLAS, PACA) ; Estacao Sao Salvador Montenegro, 138 ad rupes in silva, 500m, 14 Dec 1935, Sehnem 315 (FLAS, PACA) ; Jaquirana, Fazenda Boa Vista, sobre tronco, interior da mata, 900m, 23 Apr 1988, Wasum et al. 3964 (FLAS). SANTA CATARINA: Campo dos Padres, Bom Retiro, epifito, da mata, 1900m, 20 Dec 1948, Reitz 2610 (F, FH, FLAS, G, JE, NY, U) ; Campo dos Padres, Bom Retiro, ad arborem, 1700m, 17 Jan 1957, Sehnem 7087 (FLAS, PACA); Serra Geral , ad saxa in araucarieto, May 1890, Ule 93 (C, DUIS, FH, FLAS, G, GOET, H, JE, L, NY, S, UPS, UWM, W) . SAO LEOPOLDO: Sao Salvador, sur une pierre, 500m, Dec 1975, Sehnem 144 (JE) . SAO PAULO: Municipio de Piedade, 19 Sep 1973, Vital 2598 (FLAS, MO). CHILE. AISEN: Patagonia occidentalis, in valle fluminis Aysen [Aisen] in truncis arborum, 5 Jul 1897, Dusen A2 0 (BM, GB, H, MICH, S) . ARAUCO: Ridge S of Cerro Lanalhue, SW of Lago Lanalhue, Fundo Tranquivora, 9 . 5 km along road which intersects road P-70, western foothills of Cordillera Nahuelbuta, 37°58'S, 73°20,W, on slender branches, 200m, 25 Feb 1976, Crosby 13027 (MO). CAUTIN: Fundo El Manzano, ca 10 km E of Cunco which in turn is ca 70 km SE of Temuco, forest mainly of Nothofaaus obliqua and N. alpina. on log in wet forest, 500m, Jun 1970, Landrum 240 (MO) . CHILOE: Westpatagonien, Puerto Puyuhuapi, no date, Herzoa 48 (JE) . CONCEPCION: Maule N om Coronel, skog, skuggiga, fuktiga stallen [forest, shady damp places], 28 Jul 1917, Skottsbera & Skottsbera 444 (GB) . COQUIMBO: Constitucion, Monte Fray Jorge, an Baumen, Sep 1904, Reiche 6 (H) ; Nordchile, Fray Jorge [Monte Fray Jorge], 8 May 1941, 139 Herzoa 197 (JE) . JUAN FERNANDEZ ISLANDS: Isla Mas Afuera [Isla Alejandro Selkirk], in jugo supra Varadero, in silva Dicksonia. 800-900m, 22 Feb 1917, Skottsbera & Skottsbera 409 (GB, H, NY, S, UPS); Isla Mas a Tierra [Isla Robinson Crusoe], Valle Colonial, Quebrada Seca, stubbar v. stambaser, 435m, 20 Dec 1916, Skottsbera & Skottsbera 418 (GB, H, S) ; Isla Mas Afuera [Isla Alejandro Selkirk], Quebrada del Mono, skog, in silva, 475m, 20 Feb 1917, Skottsbera & Skottsbera 439 (BM, GB, H, NY, S) . LLANQUIHUE: Bei Cayutue, Lago Todos Santos, auf Fallholz, 1924, Wolffhuael s.n. (JE) . MALLECO: Along trail from western entrance of Pargue Nacional Contulmo, 7 km by road E on Contulmo, Cordillera Nahuelbuta, 38°00'S, 73°10'W, on tree base, 330-360m, 24 Feb 1976, Crosby 12962 (MO), 12984 (FLAS, MO) . OSORNO: Pargue Nacional Puyehue, ca 74 km E of Osorno, Aguas Calientes, forest mainly of Nothofaaus spp. and Eucrvohia cordifolia. Myrtaceae forest, on fallen trunk, 500m, 20-25 Feb 1971, Landrum 588 (MO). VALDIVIA: 2.1 km by road N of Mehuin, S of Queule, sg^e'S, 73°13'W, stream valley in well shaded forest, pendent from tree, 15m, 25 Jan 1976, Crosby 12022 (MO) ; Auf Baumwurzeln bei Valdivia, Dec 1911, Herzoa 5227 (FH, BM, H, JE, M) ; Cunco-Panguipulli, ad arbores, Aug 1921, Hollermaver 281a (S, W) . VALPARAISO: Limache (Quebrada Loreto) , sur une grande roche humide, 10 Apr 1932, Looser 2452 (G) . COLOMBIA. BOYACA: Camino de Soata al Alto de Onzaga, en guebrada a la izguierda del camino, bosgue con guercetum, 140 2800m, 23 Nov 1967, Hammen & Jaramillo 2008 (FLAS) . CAUCA: Above Tacueyo, rio Lopez, NW slopes of Nevado del Huila, Cordillera Central, Cinchona forest, 2450-2750m, 4 May 1943, Steere 7931 (FLAS) . CUDINAMARCA: Buschgiirtel uber Zipaquira bei Bogota, 3000m, 1929, Troll 2017 (JE, S) . NORTE DE SANTANDER: Pampolona, no date, Ariste-Joseoh 1911 (NY) . VALLE: Municipio El Cerrito, paramo de Pan de Azucar, ca. 03°45'N, 76°05W, bosque muy humedo montano, sobre tronco horizontal, 3500m, 27 Jun 1987, Churchill et al. 15339 (FLAS, MEXU, MO, NY). COSTA RICA. ALAJUELA: Gallito de Heredia, 19 Dec 1933, Brenes 35 (NY). HEREDIA: S slope Volcan Barba, ca 1 km WNW of rio Ciruelas, near where road 114 crosses stream, 8.2 km from San Jose de la Montana by road, 10.07°N, 84.07°W, woods and stream valley, tree near stream, 1920m, 3 May 1975, Crosby 9917 (MO). SAN JOSE: Valle de Copey, ca 30 km al sur de Cartago, bosque primario montano bajo muy humedo y potreros, 2000m, 4 Feb 1979, Griffin & Morales B100 (ALTA, B, BR, CANM, F, FLAS, MO, NAM, NY). DOMINICAN REPUBLIC. INDEPENDENCE: Near crest of Sierra de Neiba, Carretera Internacional along Haitian border, virgin rainforest on limestone mountains, 1700- 2000m, Jul 1967, Norris et al. 6692 (FLAS, NY). SAN JUAN: Trail up Pico Duarte, along stream just E of "La Comparticion," 19°02'N, 70°58'W, 2350m, rocks and adjacent vegetation, 14 Jan 1987, Buck 14189 (NY). LA VEGA: Vicinity of pyramids, 13.8 km S of Valle Nuevo, 44.7 km S of 141 Constanza, humid steep ravine (Arroyo Domingo) and adjacent fields, 2250m, 30 Apr 1982, Buck 8078 (NY). ECUADOR. AZUAY: Area Nacional de Recreacion "Cajas," S of "Surrochucho" (Laguna Llaviuco) SW of Sayausi, 2°55'S, 79°09'W, forested hill, tree trunk, humid forest, 3250m, 8 Dec 1978, Lewis 78-3220 (F, NY). CARCHI : Paramo on SW slope of Volcan de Chiles above Tamba Sucal , Cordillera Occidental, 3500m, 10 Oct 1943, Steere 9030 (FLAS, NY). IMBABURA: Cordillera Oriental, Ibarra-Mariana Acosta road, E slope above Mariana Acosta, ca 00°22'N 78°00'W, steep remnant cloud forest, 3750m, 27 Oct 1983, Steere 26825 (CANM, DUIS, DUKE, FLAS, G, H, KRAM, MEXU, NY, U) . NAPO: Salcedo-Napo road, at km 45, cloud forest, 3 600m, 16-18 Nov 1984, Laeaaard 54159H (NY). PICHINCHA: W shore of Laguna San Marcos on N slope of Volcan Cayambe, cloud forest, 3450m, 10 Oct 1984, Laeqaard & Steere 27582A (FLAS, NY, ALT A) . EL SALVADOR. CHALATENANGO : Between road and Los Planes del Monte Cristo, bath through cloud forest, clearcut and pine forest, on trunk of Dendrooanax leptooodus lm above ground, 28 Oct 1977, Watson ES-0063 (MO). GUATEMALA. JALAPA: Between Miramundo and summit of Montana Miramundo, between Jalapa and Mataguescuintla, 6 mi S of Miramundo, epiphyte on trunk in cloud forest, 2000- 2500m, 5 Dec 1939, Stevermark 32769 (F, FH, MICH, NY). SUCHITEPEQUEZ : Volcan Santa Clara, between Finca El Naranjo 142 and upper slopes, epiphyte on tree bark, 1250-2650m, 23 May 1942, Stevermark 46662 (CANM, F, FH, MICH). HAITI. ARTIBONITE: Morne de La Selle [Montagne Terrible] , Osman, trees/stumps in hardwood forest, 1650m, 15 May 1945, Holdridae 3023 (FH, FLAS, MICH, NY). OUEST: Mornes des Commissaires [Mont de Commissaires] , hardwood area in pinelands, on bark, 19 Apr 1944, Mackaness 44 (MICH, NY) . MEXICO. Cerca de Teotitlan, 2100m, 4 Sep 1966, Dull 17 (ALTA, MEXU) . CHIAPAS: N slope of Cerro Hueytepec, near Las Casas, on small boulder, 2680m, 22 Apr 1945, Sharp 3477 (MEXU, MICH, NY, TENN) . HIDALGO: Above Tenango de Doria, trunk of Caroinus. 1890m, 16 Sep 1945, Sharp 4090 (MEXU, MICH, TENN) . OAXACA: Along Hwy 175 from Tuxtpec ca 67 mi toward Oaxaca, Sierra Juarez Gap, oak-pine cloud forest, 2750m, 27 Dec 1970, Smith et al. 433 (F, MEXU, TENN). PUEBLA: 8 km SE de Huauchinango, bosque mezclado de Pinus patula y Liouidambar stvraciflua con Ouercus sp., tronco, lugares sombreados y secos, 1600m, 7 Mar 1967, Delaadillo 1379 (ALTA, DUIS, MEXU, MO). VERACRUZ: Loma Plan, Municipio de Chiconquiaco, Canada con bosque de encino, 1800m, 27 Jul 1981, Ventura 18869a (ALTA, DUKE, FLAS, MEXU, NY, U) . PANAMA. CHIRIQUI: Ridge immediately S of Cerro Horqueta peak, N of Boquete, epiphytic, 1760m, 13 Apr 1966, Crosby 3996B (DUKE, MO). 143 PERU. CONTUMAZA: Depto. Cajamarca, Pass des Cero Cunantan siidlich von Contumaza, Baum und Strauch, 29 00m, 16 Sep 1973, Heaewald & Heoewald 7309 (FLAS, NY). HUANUCO: Vicinity of Mi to, about 20 km N of Huanuco, wet shaded bank in canyon, 2750m, 8-18 Apr 1923, Bryan 405 (F, MO, NY). URUGUAY. RIVERA: Subida de Mendez (NW de Tranqueras) , r. Uruguay [Uruguay River], 22 Feb 1947, Castellanos s.n. (FH). VENEZUELA. Prope Coloniam Tovar, 1854-5, Fendler 135 (BM, FH, FLAS, G, H, NY, O, S) . MERIDA: Distrito Rivas Davila, Paramo La Negra above the town of Bailadores, on trunk of tree, 3000m, 18 Sep 1972, Griffin et al . 2063 (ALTA, CANM, DUKE, F, FLAS, MICH, MO, NAM, NY, U) . TRUJILLO: La Quebrada Cortijo, along Lara-Trujillo boundary line, above Humocaro Bajo, dense woods below paramo and ridge top, 2600-2800m, 16 Feb 1944, Stevermark 55328 (F, FH) . ZULIA: Distrito Perija, Serrania de los Motilones- Sierra de Perija, dense mixed broad-leaved forest, 3000m, 27 Jun - 5 Jul 1974, Tillet et al. 747-819 (FLAS) . AFRICA. MADAGASCAR. Mt. Tsaratanana [or Mt. Madagascar], 1200-2400m, Mar 1924, Perrier de la Bathie s.n. (H). MALAWI. MULANJE: Southern Province, Mulanje Mts., Lichenya Plateau, 15°58*S, 35°30'E, 1800-2000m, 9-10 Mar 1973, Rwarden 11792 (0, VBI) . 144 MOZAMBIQUE. MANICA E SOFALA: Gorongosa Mt. , near Gogo Peak, stream bank rock, deep shade, in forest, 1700m, 6 Jul 1955, Schelpe 5552 (BM, C, S) . RHODESIA [ZIMBABWE]. INYANGA: Inyanga District, W slope of Little Inyangani, 1832B4, 36KVQ874795, mixed evergreen forest, on tree, 1860m, 3 0 Oct 197 6, T. Miiller 2635 (L, MO) . SOUTH AFRICA. TRANSVAAL: Mariepskop Plantation Nature Reserve, 40 km N of Pilgrim's Rest, 23.31S, 30.52E (grid 23.30DB), vicinity of power plant just below radar station, terrestrial, in shade of rocks, 2050m, 12 Jan 1973, Crosby & Crosby 7637 (DUKE, L, MO) ; Mariepskop, central summit, Widdringtonia-Podocarpus stand, on ground and epiphytic, 1900m, 2 Dec 1969, Vorster 1761b (L) . TANZANIA. ARUSHA: Arusha National Park, E slopes of Meru Crater, along trails between Kitoto and Cabin at Njeku, ca 3 km ESE of summit of ash cone in Meru Crater, 3.14°S, 34.47°E, near stream, on tree, 23 Dec 1973, Crosby & Crosby 13266A (MO). KILIMANJARO: Kilimanjaro Mts., behind the Mandara/Bismark Hut, high altitude mossy forest of Hagenia abvssinica-Podocarpus milaniianus. 2700m, 14 Sep 1970, Pocs 6243/B (VBI) . MOROGORO: Morogoro District, Uluguru Mts., NE ridge of Bondwa peak, high altitude mossy forest, on bark, 1800-1950m, 7 Sep 1972, Pocs 6782/B (G, L, MO, VBI). TANGA: West Usambara Mts., Shagayu Forest Reserve, 2 km SW of the Shagein peak, on a summit, mossy cloud forest, 145 lignicolous, 2000-2150m, 15 Mar 1984, Borhidi 8445/AB (F, G, MO , UPS , VBI ) . Rigodium toxarion var. toxarion commonly is an epiphyte (on tree trunks and branches) and also grows on a variety of other substrates (logs, rocks, stumps, soil) . Generally the species occurs in damp, high elevation forests (rain forests, cloud forests, fog forests, elfin forests) , as well as in more exposed habitats such as paramos, ravines, and disturbed areas. As defined here, R. toxarion var. toxarion is the most widespread taxon in the genus with a disjunct distribution in Central/South America and eastern Africa (Fig. 30) . In Africa, R. toxarion var. toxarion occurs at 1750 to 2700 m, generally in mixed evergreen rain forests (dominated by Podocarpus, Ocotea. Cvathea. and Erica) or in elfin forests or fog forests (dominated by plants such as tree ferns, Cyathea) . In Central America, the variety has been collected in high altitude forests (ca 1500 to 3000 m) characterized by such tree species as Magnolia (Dominican Republic) or Pinus, Ouercus . Podocarpus, Alnus, Liguidambar. and Clethra (Mexico) . In northern South America (Colombia, Venezuela, Ecuador, Peru, and Bolivia) a range of relatively higher elevations of 2400 to 3750 is reported. Colombian forests are dominated by Ouercus. Weinmannia. Clethra and Chinchona ; in Venezuela, R. toxarion var. toxarion has been collected in the paramos. Collections from southeastern Brazil (where Araucaria commonly dominates the forest) cite 146 relatively lower altitudes (30 to 100 m) than in the northern parts of South America, although a few specimens were collected at 1900 to 2500 m. Finally, at the southernmost limit of the distribution (along the Andean Cordillera in Chile, Fig. 32) , R. toxarion var. toxarion consistently occurs at lower elevations (2 00 to 900 m) than in the rest of its range, commonly in forests dominated by Nothofagus (with Eucryphia , Mvrceuqenia. Aextoxicon, Laurel ia. and Weinmannia) . In addition, this variety is found on both islands (Isla Alejandro Selkirk and Isla Robinson Crusoe) of the Juan Fernandez Islands. Ricrodium toxarion is basal in the phylogeny of Riqodium species (Figs. 20, 21) and is metaphyletic as well, since no autapomorphies define it. The plants are typically arborescent with the ancestral leaf type (Figs. 19B, 27A and D) , i.e., with a weak decurrency (see chapter on phylogeny). The stem leaves also tend to be longer than wide (Fig. 19D) with long acumens (Fig. 19E) . The intramarginal band, although differentiated, is composed of cells + larger and very slightly thicker-walled than the midlaminar cells (Fig. 271) and is almost indiscernible in surface view (Fig. 27K) . In addition, the midlaminar cells are very weakly prorulose with even walls (Fig. 27J) , in marked comparison to the other species in the genus. The epithet of R. toxarion is the oldest in the genus, originally described sub Hypnum (Schwagrichen, 1816) and later transferred to Ricrodium (Jaeger, 1878) . Since R. 147 toxarion is a widespread and variable species spanning two continents, populations characterized by certain slight variations were often assigned individual species names. As noted in the chapter on Taxonomic History, this process resulted in much confusion concerning the delimitation of species within the whole genus, especially the 13 epithets that are reduced in synonymy under R. toxarion var. toxarion in this revision (see Table 1) . For example, although R. toxarion was originally described from Hispaniola, the name commonly became associated in floras with specimens from South America, while "R. gracile" (originally described from Costa Rica) was associated with Central America. Some collections in Brazil ("R. nano-fasciculatum" and to a lesser extent, "R. araucarieti" and "R. hamirameum" ) tend to have acumen lengths at the shorter end of the spectrum for R. toxarion. a feature which is found throughout the range of variation of the species. "Riaodium leptodendron, " associated with Bolivia, presumably is characterized by abundant capsules (Mialler, 1897a) , a feature also found to be unexceptional within the total variation of R. toxarion. Much confusion in the literature concerns "R. solutum." originally described from Ecuador by Taylor (1846) . Miiller (1851) noted its similarity to R. implexum and later (1882) distinguished R. arqentinicum from R. solutum on the basis of capsule characters, without specifying these characters or describing either capsule type. Mitten (18 69) confused 148 matters further by placing R. (Hypnum) solutum in synonymy with R. (Hypnum) toxarion. along with R. (Hypnum) implexum and R. (Hypnum) brachypodium . Probably due to the great distance separating Africa and South America, it apparently did not occur to bryologists that collections from these two continents may be equivalent. Brotherus (1897) distinguished R. kilimandscharicum (from Tanzania) from the South American Rigodium species by the "delicate' appearance of the African plants which had attenuate branches frequently rooting at the tips (Fig. 29K) . This feature is actually not at all uncommon in the South American specimens of R. toxarion var. toxarion. In fact, the African collections exhibit a wide range of morphological variation in plant and leaf size (Fig. 29L-N) comparable to that found in the South American specimens (Fig. 27F-H) . Theriot (1925) demarcated R. niveum (Madagascar) from R. kilimandscharicum (continental Africa) on the basis of the entire to weakly sinuate margins, oblong median cells and round marginal cells of the former (Fig. 29D) — all character states found within the various specimens in eastern Africa (Fig. 29A-J) , as well as those from Central and South America. Some specimens of R. toxarion var. toxarion are lax, poorly branched, and sterile (Fig. 31A) , although the collections may contain profuse stems. These lax and sterile specimens found in the loan material exhibit a curious distribution (Fig. 32): they are restricted to 149 locations at the southernmost part of the range of R. toxarion in Chile (ca 35°S to 46°S) , where the species occurs at much lower altitudes than further north in South America or in Africa. A species ("R. pendulum") was described for this form by Herzog and Theriot (in Herzog, 1939) . In addition to the poorly developed stems, the stem leaves are also very reduced (Fig. 3 IB) , but have the characteristics of larger R. toxarion var. toxarion leaves. In addition, sometimes a specimen with a typical robust arborescent habit has such lax stems attached (Fig. 31C-E) , thereby establishing "R. pendulum" as a minor variant of R. toxarion growing at the limit of the range of the species. lb. Ricfodium toxarion var. robustum (Broth, in Skottsb.) Zomlefer. var. nov. Rigodium robustum Broth, in Skottsb., Nat. Hist. Juan Fernandez 2(3): 443. 1924. Types: Chile. Juan Fernandez Islands: Mas a Tierra [Isla Robinson Crusoe], Salsipuedes, snar-skog a stenig kam/in silva lapidosa jugi, 625 m, 13 Jan 1917, Skottsbera & Skottsbera 429 (lectotype here designated: H-BR! ; isolectotypes: GB!, JE! , S!; isolectotype as 429 p.p.: S!) . Riaodium looseri Ther. , Rev. Chil. Hist. Nat. 31: 257. Plate XVII, Figs. 3a-f. 1928. Types: Chile. Juan Fernandez Islands: Isla Mas a Tierra [Isla Robinson Crusoe], chemin au Portezuelo, 13 Feb 1927, Looser 8 p.p. (lectotype here designated: PC! ; isolectotypes: G! ; 150 probable isolectotype as 84B: B! ; possible isolectotypes as s.n.: FH! , W!); CHILE. Juan Fernandez Islands: Apr 1830, Bertero s.n. (syntypes: G! , PC!). Plants medium to large, dendroid, erect or sometimes pendent. Stipes to 2.1 cm long. Stems to 4.5 cm long, 220- 475 urn in diameter. Stem leaves ovate at base and abruptly narrowed to a well-developed + long acumen, + subulate, 0.70-1.60 x 0.42-1.00 mm, longer than wide with length/width ratio (1.08-) 1.30(-1.51) ; acumen 0.38-0.66 mm long, (41- )44(-50)% of leaf length measured from point of insertion. Secondary branch leaves very narrowly ovate, 0.35-1.3 3 x 0.15-0.50 mm, with length/width ratio (2.26-) 2.44 (-3 .12) . Representative specimens examined. CHILE. JUAN FERNANDEZ ISLANDS: Isla Mas Afuera [Isla Alejandro Selkirk], innermost accessible part of Quebrada Casas, moist shaded ledge of cliff beside stream, 29 Nov 1965, Hatcher & Enael 116A (FH, NY); Mas a Tierra [Isla Robinson Crusoe], Quebrada Frances, slope of Cordon Chifladores, on Drimvs . 6 Jan 1955, Kunkel M74 (H) ; Isla Mas Afuera [Isla Alejandro Selkirk], Quebrada de las Casas, in canyon on moist wall, 2 0 Jan 1955, Skottsbera & Skottsbera M98 (H, S) ; Isla Mas Afuera [Isla Alejandro Selkirk], Sanchez-Tolten forest, on dead prostrate luma rMyrceuqenia] trunk, 700m, 17 Feb 1955, Skottsbera & Skottsbera M197 (FH, GB, H, S, UPS) ; Isla Mas a Tierra [Isla Robinson Crusoe], Quebrada Damajuana, in humid forest, 400-450m, 3 Mar 1955, Skottsbera & Skottsbera M306 151 (S) ; Isla Mas a Tierra [Isla Robinson Crusoe], ridge between Rabanal and Quebrada Piedra Agujereada, 500m, 12 Mar 1955, Soarre M317 (H, S, UPS). Rigodium toxarion var. robustum is restricted to Isla Alejandro Selkirk (Isla Mas Afuera) and Isla Robinson Crusoe (Isla Mas a Tierra) of the Juan Fernandez Islands. The variety occurs in moist forests and also more exposed areas (such as road and stream banks) at relatively low elevations (200 to 700 m) . This variety shares the characters discussed for R. toxarion var. toxarion, and has the autapomorphy of narrow branch leaves (length/width ratio averaging 2.44 compared to ca 1.95 for R. toxarion var. toxarion) , in addition to the restricted distribution. The stem leaves of R. toxarion var. robustum tend to be large (ca 1.30 x 0.90 mm) within the size range of the species, and the upper stem leaves, in particular, tend to gradually (rather than abruptly) taper to a relatively "short" acumen (Fig. 33C and D) . As noted by Robinson (1975) , specimens of R. toxarion var. robustum ("R. robustum") are not necessarily large, although Brotherus (1924) originally described the plants as "robust" with the naked eye. However, many habits do have a stout appearance (Fig. 33A) , probably due to the large stem leaves and the spreading, narrowly lanceolate branch leaves (Fig. 33E) , which may add to the appearance of bulk to the stems and branches, respectively. Due to the often large stem 152 leaves with somewhat short acumens, specimens R. toxarion var. robustum (as R. robustum) have often been annotated as 11 R. arborescens" (= R. brachypodium in the present study) . The confusion concerning these species is discussed in detail under R. brachypodium. but basically R. toxarion var. robustum lacks the apomorphic character states (e.g., strong border, prorulose and porose midlaminar cells) that define R. brachypodium. Rigodium looseri is tentatively placed in synonymy here, a transfer advocated by Robinson (1975) . The branch leaves of the type specimens of R. looseri are the widest found for this variety (length/width ratio 2.26), although still much narrower than branch leaves of R. toxarion var. toxarion. In addition, the stem leaves are relatively small (ca 0.70 x 0.42 mm) but gradually taper to relatively short acumens. The phenetic analysis is inconclusive as far as supporting the inclusion of R. looseri (see Fig. 24A and B, #13) since only three specimens (including the lectotype of R. looseri) were eventually determined as R. toxarion var. robustum. However, the specimen of R. looseri does not appear to be phenetically close to the other two specimens included in the phenetic study. FIG. 27. Riqodium toxarion var. toxarion: Gametophytic Features. A. Habit. B. Portion of stem showing position of leaves. C. Stipe leaf. D. Stem leaf. E. Branch leaf. F- H. Stem leaves from various South American specimens, showing variation in size and morphology. F. Relatively large stem leaf (Chile) . G. Slender stem leaf (Peru) . H. Stem leaf with relatively short acumen (Brazil) . I. Cross section of stem leaf. J-K. Areolation of leaf. J. Midlaminar cells. K. Marginal and intramarginal cells. A- E, I-K from Tonduz TPittier No: 1 5667 (BR, syntype R. gracile) ; F from Reiche 6 (H) ; G from Brvan 405 (MO) ; H from Wasum et al. 3964 (FLAS) . 154 K ooqoooOOOOOOooo) 40/jm ifl fifflfl III «TO FIG. 28. Riqodium toxarion var. toxarion: Sporophytic and Related Gametophytic Features. A. Perichaetial leaf. B-C. Areolation of perichaetial leaf. B. Basal cells. C. Upper cells. D. Portion of primary branch with perigonia. E. Perigonium. F. Perigonial leaves. G. Capsule. A-C, G from Tonduz TPittier No: ] 5667 (BR, syntype R. gracile) ; D-F from Ventura 18869a (FLAS) . 156 0.3mm FIG. 29. Riqodium toxarion var. toxarion: Variation in African Specimens. A-J. Areolation of stem leaves from various specimens. A-F. Variation in leaf margins. G-J. Variation in midlaminar cells. K. Habit with attenuate branches. L-M. Stem leaves from various specimens showing variation in size and morphology. A, G, N from Schelpe 5552 (S) ; B, H, K, L from Volkens 2349 (JE, isolectotype R. kilimandscharicunn ; C, I from Pocs 6782/B (MO) ; D, J, M from Perrier de la Bathie 168 (PC, lectotype R. niyeum) ; E from T. Muller 2635 (MO) ; F from Rvvarden 11792 (VBI) . 158 °0oc # D /Oc II II II II SI 1! TOW m j »d 4 m flRr m 0.3mm c o •H u TO X o -p e 3 •H o a •H O c o •H I •H 4J o n u H fa 160 c o k_ CO X o i c o zs Q 1 i b CM ^ |\ <* t V A**^ °c 3 T °6 c\j E J£ o o JlO < o oc < Ul u i< t-2 2* O iu COH is > • o o cr ^6 Fig. 31. Rigodium toxarion var. toxarion: Lax, Sparsely Branched Specimens. A. Habit. B. Stem leaf. C. Habit with both arborescent and lax, sparsely branched stems. D. Stem leaf from arborescent stem. E. Stem leaf from lax stem. A-B from Schwabe 79/b2 (JE, lectotype R. pendulum) ; C-E from Skottsbera & Skottsbera 409 (GB) . 162 5mm 0.3mm FIG. 32. Southernmost Range of Rigodium toxarion var. toxarion. Southernmost Range of R. toxarion 164 • arborescent specimens Olax, poorly branched specimens (always sterile) ^%* SOUTHERN CHILE AND ARGENTINA r- 0 300km FIG. 33. Riaodium toxarion var. robustum. A. Habit. B. Stipe leaf. C-D. Stem leaves from various specimens. E Portion of secondary branch. F-H. Branch leaves from various specimens. I. Areolation (marginal to midlaminar cells) of stem leaf. A-C, E, F, I from Skottsbera & Skottsberg 429 (S, isolectotype R. robustum); D, G from Skottsbera & Skottsbera M98 (H) ; H from Skottsbera & Skottsbera 423 (GB) . 166 wmmm ini 40jum 167 2. Riqodium brachypodium (C. Mull.) Par. Hvpnum brachypodium C. Mull., Svn. 2: 445. 1851. Riqodium brachypodium (C. Mull.) Par., Ind. Brvol . 1140. 1898. Types: Chile. Valparaiso: Valparaiso, no date, Bertero s.n. (lectotype: BM! ; possible isolectotype as Anonymous s.n.: L!); lectotypif ication in Zomlefer (1991) . Hvpnum arborescens C. Mull., Bot. Zeit. 16: 172. 1858. Riqodium arborescens (C. Mull.) Broth., Nat. Pfl. 1(3): 1160. 1909. Types: Chile. Valdivia: Ad truncos arborum prope coloniam Arique [also spelled "Arrique" on specimen labels], Jul 1851, Lechler 629 (lectotype here designated: BM! ; isolectotypes: BM (4 specimens)!, BR (2 specimens)!, G! , GB! , H! , L (2 specimens)!, MICH!, NY (3 specimens)!, 0!, S (4 specimens)!, UPS!, W (3 specimens) ! ) . Plants medium to large, dendroid (or very rarely subsimple) , erect, pendent, or sometimes creeping, irregularly to ± regularly pinnately branched, on tree trunks and branches or sometimes on logs, rocks or soil, green, yellow-green to yellowish brown, sometimes rooting at tips of stems and primary branches. Stipes + well- developed, to 4.0 cm long. Stems to 9.0 cm long, 275-680 urn in diameter. Primary branches generally 15-35 per stem, spaced 1.0-10.0 mm apart along the stem, proximal ones to 3.5 cm long, gradually becoming shorter above, sometimes 168 attenuate (and then often rooting at tips) . Secondary branches generally 5-2 0 per primary branch, to 2.0 cm long. Tertiary branches present. Stem leaves broadly ovate at base and abruptly narrowed to a well-developed acumen, 0.68- 1.60 x 0.72-1.39 mm, with length/width ratio (0.93-) 1. 10 (- 1.30), spreading to squarrose, with clasping and concave base, longitudinally undulate, occasionally auriculate, somewhat decurrent with decurrent portion 0.06-0.14 mm long (5-13% of total leaf length); acumen 0.14-0.75 mm long, (20- )32(-56)% of leaf length measured from point of insertion; margins erect to reflexed, generally serrate throughout; costa single, 0.43-1.25 mm long, 33-96 urn wide at base, 2-3- stratose in lower half; alar cells quadrate to oblate, 5.8- 12.7 x 7.1-13.3 um; marginal cells 1-2-seriate, oblong- rhombic, 10.6-22.7 x 3.3-6.3 um; intramarginal cells (4-)5- 7-seriate, short-oblong, 14.7-29.5 x 7.8-12.6 um, with thicker walls than the midlaminar cells and forming a moderately strong intramarginal band; midlaminar cells rhombic to rhomboidal, 18.1-33.2 x 3.9-6.8 um, porose with walls somewhat uneven, very prorulose and often with (upper) end walls projecting prominently as well-developed papillae (prorulae) on the dorsal surface. Stipe leaves with similar shape and orientation as stem leaves, 0.74-1.44 x 0.67-1.14 mm; acumen 0.17-0.76 mm long; costa absent or rarely present and then very weak. Secondary branch leaves narrowly ovate, acute, 0.28-0.61 x 0.19-0.37 mm, with length/width ratio ( 1. 43-) 1.82 (-2.25) , erect-spreading to spreading; margins 169 serrate. Perigonial leaves ovate, acute to shortly acuminate, 0.51-0.85 x 0.26-0.52 mm. Antheridia 240-475 x 90-155 urn; paraphyses 7-12 cells long, 300-550 urn long. Perichaetial leaves subulate, 1.16-2.68 x 0.35-0.92 mm, long-acuminate with acumens 0.28-0.60 mm long; basal cells rhomboidal, 30.0-105.0 x 7.0-11.3 urn, porose, prorulose, frequently papillose with one large central papilla; apical cells rhombic, + sinuous, 18.3-36.0 x 3.3-6.7 urn. Archecfonia 350-590 urn long, 40-60 wide at venter; paraphyses 9-19 cells long, 425-700 urn. Seta to 2.3 cm long. Capsule urn 1.10-1.90 x 0.45-0.77 mm; upper exothecial cells 16.7- 25.0 x 14.0-23.3 um; median exothecial cells 31.7-61.8 x 23.3-34.0; cells in neck 23.3-52.0 x 9.7-16.0. Operculum 0.50-0.88 mm long, long-rostrate with beak 0.20-0.50 mm long. Exostome teeth 527-690 um long, 80-120 um wide at base. Endostome segments 255-383 um long, 38-62 um wide at base; basal membrane 160-242 um high; cilia (l-)2-3, 148-328 um long. Spores 16-22 um in diameter. Calyptra to 3.0 mm long. 2a. Riqodium brachypodium (C. Mull.) Par, var. brachypodium Plants dendroid (or rarely subsimple) , erect, pendent or sometimes creeping, irregularly pinnately branched. Stipes well-developed, to 4.0 cm long. Stems to 5.5 cm long, 320-680 um in diameter. Primary branches generally 15-30 per stem, spaced 1.0-3.5 mm apart along the stem, proximal ones to 3.5 cm long, gradually becoming much shorter above, sometimes attenuate (and then often rooting 170 at tips) . Secondary branches generally 5-15 per primary branch, to 2.0 cm long. Stem leaves broadly ovate at base and abruptly narrowed to a well-developed short acumen, 0.68-1.60 x 0.72-1.39 mm, ca as long as wide with length/width ratio (0.93-) 1. 07 (-1. 27) , somewhat decurrent with decurrent portion 0.07-0.14 mm long (8-13% of total leaf length); acumen 0.14-0.61 mm long, (20-) 29 (-45) % of leaf length measured from point of insertion; margins erect to reflexed; costa single, relatively broad and well- developed, 0.43-1.25 mm long, 45-96 um wide at base; intramarginal cells short-oblong, 14.7-29.5 x 7.8-12.6 um; midlaminar cells 18.1-33.2 x 3.9-6.8 um. Stipe leaves 0.74- 1.34 x 0.67-1.14 mm; acumen 0.17-0.65 mm long. Representative specimens examined. ARGENTINA. CHUBUT: Lago Menendez, 2 Nov 1945, Castellanos s.n. (FH) ; Lago Menendez, at the end of SW arm of lake, on level ground on S side of a river, Nothofaaus dombeyi forest, 20 Jan 1938, Kalela B244f (H) ; Lago Menendez, on river uniting Lago Menendez and Lago Rutalaufguen, top of river bank, Nothofaaus dombeyi forest with Austrocedrus and Lomatia, 21 Jan 1938, Kalela B249i (H) . NEUQUEN: Lago Correntoso, on road a few hundred meters from hotel, Nothofaaus dombeyi - Mavtenus forest, 6 Nov 1937, Kalela B3e (H) ; Isla Victoria (Lago Nahuel Huapi) , 820m, 21 Jan 1951, Sleumer 1718 (B, S) . RIO NEGRO: Lago Nahuel Huapi, in valley leading from Puerto Blest to Lago Frias, at foot of E slope, Nothofaaus dombeyi- Laurelia forest, 30 Nov 1937, Kalela B93a. B93f (H) ; Lago 171 Mascardi, in deep depression ca 8 km S of Hotel Tronador, Nothofaaus dombeyi forest, 8 Dec 1937, Kalela B130a (H) ; Lago Mascardi, El Maitenal, 3-4 km N of park warden's residence, Nothofacrus dombeyi-Austrocedrus forest, 9 Dec 1937, Kalela B133c (H) . SANTA CRUZ: Southernmost end of Lago Argentina, W side of Laguna Fria, 51 °S, 73 °W, mature forest dominated by Nothofaaus pumilio, with N. betuloides and N. antarctica in places, 15-18 Mar 1972, Cantino M-41 (MO); Depto. Lago Argentino, Seno Mayo, Bahia Toro, 50°17'S, 73°16*W, bosque mixto de Nothofaaus betuloides y N. pumilio con Drimys winteri. Mavtenus magellanica. con cascada fertil, 30 Jan 1988, Matteri & Schiavone 4925 (Herb. Matter i) . CHILE. AISEN: Patagonia occidentalis in valle fluminis Aysen [Aisen] in truncis putridis, 24 Jan 1897, Dusen 482 (BM, FLAS, H, JE, MICH, NY, O, S, W) ; Westpatagonien, Punta Leopardo [Leopardos] , 24 Feb 1921, Hicken 126 (JE) . CAUTIN: Termas de Palguin, along rio Palguin, 39°22'S, 71°44,W, Nothofaaus forest, moist bank, beyond banos, 730m, 22 Jan 1976, Crosby 11841 (FLAS, MO) ; Depto. Villarrica: Pucon, im Urwald auf des Halbinsel, auf Baumen, 7 Feb 1935, C^. Hosseus 147 (JE) ; Anden von Villarrica, auf Baumstammen, 1897, Neger [Dusen No:] 10 (L) . CHILOE: Isla Chiloe, Chepu, S side of rio Chepu, 42°03'S, 74°02'W, forest (Nothofaaus nitida. Laurel ia, Weinmannia. Chusguea, etc.), on tree base, 0m, 3 Feb 1976, Crosby 12365 (MO); Tepuhueico [Lago Tepuhueco] , 15 Mar 1958, Oberdorfer 172 279b (JE) . CONCEPCION: Chile australis prope Talcahuano oppidam in terra, 9 Sep 1896, Dusen 202 (CHR, FLAS, GB, H, JE, NY, S) ; Concepcion, Dec 1903, Elliott 139 (H, L, O) . COQUIMBO: Chaopa, Cerro Talinay 5 km al N de Huentelauquen; bosque de Mirtaceas, en tronco de Myrceugenia correalfolia, 600m, 15-16 Jul 1978, Mahu 12530 (MO). CURICO: Fundo El Manzano, at La Montana, ca 40 km E of Curico on the north side of the rio Teno, forest mainly of Nothofaaus obliqua, on rock in open forest, 30 Apr 1970, Landrum 166 (MO) . JUAN FERNANDEZ ISLANDS: Isla Mas Afuera [Isla Alejandro Selkirk] , Quebrada Casas [Quebrada Baquedano] , innermost accessible part, wet shaded boulders in stream bed, 9 Nov 1965, Hatcher & Enael 631 (DUKE, G, MICH, NY). LINARES: Bullileo ca 50 km E of Parral in the pre-cordillera, near Laguna Amargo, forest of Nothofagus obliqua and N. glauca on slopes, forest and thickets of Myrtaceae in low wet areas, rock in forest, 17 Mar 1971, Landrum 1510b (MO) . LLANQUIHUE: Chile australis, lacus Llanquihue ad Puerto Octay, Dec 1896, Dusen s.n. (S) ; Lago Todos los Santos, 41°10'S, 72-20'W, on shady andesite cliff, 160m, 10 Feb 1967, Seki 64 (H) . MAGALLANES : West Patagonia, Smith Channel [Canal Smith], Dec 1923, Gusinde 380 (GB, S, W) ; 106-107 km from Punta Arenas, gallery forest along the brook between Morro Chico and Laguna Blanca, some 10-15m broad Nothofagus antarctica stand steppe on both sides, 7 Feb 1938, Kalela B282c (H) . MALLECO: Along trail from western entrance of Parque Nacional Contulmo, 7 km by road E of 173 Contulmo, Cordillera Nahuelbuta, 38°00'S, 73'10'W, on rotting log, 330-360m, 24 Feb 1976, Crosby 12992 (MO) ; Chile australis in monte "Cordillera de la Costa" supra Angol oppidam, in truncis arborum, 800m, 5 Nov 1896, Dusen 357 (BM, DUIS, FH, H, JE, MICH, NY, 0, S, UPS, W) . MAULE : Empedrado, in the Cordillera de la Costa, ca 43 km SE of Constitucion, deciduous forest mainly of Nothofagus obligua, N. glauca and N. alessandri. on rock in wet forest, Aug 1970, Landrum 304. 305 (MO). NUBLE: San Fabian ca 60 km E of San Carlos, about 2-5 km from San Fabian along trail to Lago Valiente, on rock with humus, 19 Mar 1971, Landrum 1509a (MO); Recinto, ad saxa, 800m, 14 Apr 1929, Roivainen 970 (H) . OSORNO: Agua Caliente, margin of rio Chanleufu near falls, 4 km by road from Termas de Puyehue along road to Refugio Antillanca, 40°43'S, 72°20'W, on rocks, 400m, 27 Jan 1976, Crosby 12038 (MO) ; Fundo Colimahuida, 1940, Herzog s.n. (JE) . VALDIVIA: Forest (Nothofagus. Weinmannia. Saxegothaea. Drimvs , Chusquea. etc.) on W slope of Cordillera Pelada, 8.8 km by road W of El Mirador on road between La Union and Punta Hueicolla, 40°07'S, 73°16'W, on tree trunk, 580m, 18 Feb 1976, Crosby 12794 (MO); 1887-88, Hahn s.n. (B, BM, C, CANM, DUKE, F, FLAS, MICH, MO, OXF, NY, S) ; Panguipulli, an der Rinde von Waldbaumen, 240m, 10 Jun 1921, Hollermayer 259 (B, S, W) ; Cunco-Panguipulli, Aug 1921, Hollermaver 281p.p. (S) ; Rio Blanco, zwischen dichten Chusquea-Bestanden verbreitet, Dec 1953, Kunkel 2029 (B, H) . 174 VALPARAISO: Guillota, ad rapes et arborum locio umbrosis in sylva de la Palma, 1829, Bertero 1054 (BM) . Rjgodium brachvpodium var. brachypodium is typically an epiphyte (on tree trunks and branches) , but also occasionally grows on logs, stumps, rocks, and soil. The species is widespread in damp shady forests dominated by Nothofaaus (with Podocarpus. Myrceugenia . Weinmannia. Saxegothaea. Drimys . Chusquea. Austrocedrus r Maytenus . and Laurelia) and sometimes occurs in disturbed, open areas as well, at altitudes typically 500 to 1350 m, with elevations of 0 to 500 m not infrequently cited on the labels. The distribution of R. brachvpodium (along the Andean Cordillera of Chile-Argentina, ca 31°S to 55°S, Fig. 37) and R. pseudo- thuidium define the southernmost range of the genus, but the range of R. brachvpodium does not extend as far eastward as that of R. pseudo-thuidium (i.e., no collections from Tierra del Fuego, Argentina) . Like R. pseudo-thuidium . R. brachvpodium also occurs in the Juan Fernandez Islands only on Isla Alejandro Selkirk (Isla Mas Afuera) and not on Isla Robinson Crusoe (Isla Mas a Tierra) . Rjgodium brachvpodium var. brachvpodium retains the ancestral arborescent habit, while exhibiting some apomorphic character states of a strong intramarginal band of cells (Fig. 34H and J) and a moderately decurrent leaf base (8 to 13% of the total leaf length; Fig. 19B) . The cell border, however, is narrow (four to seven cells wide) , 175 although the cells themselves have much thicker walls than those of R. toxarion. The stem leaves are likely to be ca as long as wide (Fig. 19D) with short acumens (Fig. 19E) . The costa of the stem leaves of this variety tend to have a very strong, broad costa (to ca 96 urn wide at base) , and the plants tend to develop a robust habit. The autapomorphy of the species (i.e., occurring in R. brachypodium var. tamarix as well) is the extremely prorulose condition of the midlaminar cells, the ends of which often project as well-developed papillae (prorulae) on the dorsal surface (Figs. IOC and D, 34J) . This character was evidently first noted by Robinson (1975) who described them as "knobs on end walls projecting abaxially as papillae." Although not all specimens have prorulose midlaminar cells as illustrated here, a few such projecting cells may be found on any given stem leaf. In addition, the walls of the midlaminar cells are porose (but not as uneven as in R. implexum and R. pseudo-thuidium) . Although Theriot (1917) reported that R. brachypodium (as R. arborescens) frequently fruits and often has two setae per perichaetia, examination of numerous specimens of R. brachypodium over its entire range does not reveal any exceptional amount of sporophyte production in comparison to other species of Riqodium. The epithet of R. arborescens has been more commonly used both with collections and in the literature than the name R. brachypodium. possibly because the situation 176 concerning the type(s) of R. brachvpodium was unclear (see Zomlefer, 1991) , in addition to the vague description provided by Muller (1851), the original author. Miiller (1851) did indicate that R. brachvpodium was definitely far removed from R. implexum and R. toxarion, but did not specify the distinguishing characters. Despite these problems, however, Ricrodium brachypodium is the older name with priority. The stem leaves of the type specimen of R. brachypodium (Fig. 34F) are much smaller than most representatives of the species (Fig. 34D) . In contrast, the nomen nudum , "R. carnosulum" (Dusen, 1903; Dusen 482) , represents the largest and most robust plants with the largest stem leaves (Fig. 34G) in R. brachvpodium. As noted in the initial discussion of the distribution, R. brachvpodium var. brachvpodium occurs on the Juan Fernandez Islands (Isla Alejandro Selkirk) , and is represented here in the loan material by one specimen (Hatcher & Enael 631) . Although he annotated this specimen as "R. arborescens" in 1965, Robinson (1975) later includes this specimen in his concept of "R. robustum" in his moss flora of the Juan Fernandez Islands. Here he maintains that R. arborescens is restricted to mainland Chile. The specimen in guestion, however, fits even his concept of R. arborescens (= R. brachypodium) : the stem leaves have a moderately strong intramarginal border and very prorulose and porose midlaminar cells (some of which project as dorsal papillae) . The stem leaves of "R. robustum" (= R. toxarion 177 var. robustum in this revision) , though, have a weak border and weakly prorulose midlaminar cells with even walls. I do agree with Robinson's annotations of Brotherus ■ (1925) and Bartram's (1959) "R. arborescens" (R. brachypodium) specimens as R. robustum (= R. toxarion var. robustum) /R. toxarion (= R. toxarion var. toxarion) . As discussed in the chapter on phylogenetics, the cladistic analyses indicate that R. brachypodium may be paraphyletic (compare Figs. 20 and 21). However, intermediates in habit form link the two varieties, as well as the synapomorphy of the midlaminar cells with prorulae (see discussion in chapter on phylogeny) . Occasionally when stems of R. brachypodium var. brachypodium become elongated, the arborescent form is less distinct and the branching pattern approaches + regularly pinnate. These tendencies for the development of regularly pinnate branching and loss of well-developed stipe are carried to the extreme in R. brachypodium var. tamarix (discussed below) . In some situations R. brachypodium var. brachypodium exhibits the retention of the stem leaf ancestral morphology (a relatively short decurrency) , as well as the tendency for a long acumen (greater than one third of the leaf length) . When the stems become attenuate and root at the tips, the leaves in the elongated area may have a different shape (short decurrency, long acumens; Fig. 3 6A) . This tendency is consistent in R. brachypodium var. tamarix (discussed below) in which all the stem leaves are long acuminate. Out 178 of the hundreds of R. brachypodium var. brachypodium specimens examined, one transitional arborescent specimen (Hollermayer 281p.p. ) has numerous stem leaves with long acumens (Fig. 36B) . Other minor variants (in habit) are a few very poor specimens with lax, sparsely branched plants (as in R. toxarion and R. adores sum, both also arborescent species) , generally scattered throughout the north central part of the range of R. brachypodium (Cautin and Valdivia, Chile; Chubut and Rio Negro, Argentina) and are probably the result of localized unfavorable environmental conditions. 2b. Riqodium brachypodium var. tamarix (C. Mull.) Zomlefer, var. nov. Riqodium tamarix C. Mull., Hedwiqia 36: 139. 1897. Type(s): Chile. Aisen: Hale Bay, canali occid. patagonia, [voyage of the] Viaggio Carocciolo, 3 Jul 1884, de Amezaga s.n. (lectotype: RO!); Fuegia, Hale Bay, Hb. Horti Romani, Hb. Miiller 1885, Anonymous s.n. (probable isolectotype: BM!); Hale Bay, West Channel, [voyage of the] Viaggio Carocciolo, Erbario Roma, com. Pirotta, 3 Jul 1882, Anonymous s.n. (possible isolectotype: S!); lectotypif ication in Zomlefer (1991) . Plants pendent or creeping, + regularly pinnately branched. Stipes + well-developed, to 2.1 cm long. Stems long and straggling, to 9.0 cm long, 275-370 urn in diameter. Primary branches generally 15-35 per stem, spaced 3.0-10.0 mm apart along the stem, proximal ones to 2.5 cm long, 179 gradually becoming + shorter above. Secondary branches generally 5-20 per primary branch, to 1.2 cm long. Stem leaves broadly ovate at base and abruptly narrowed to a well-developed long acumen, subulate, 0.93-1.13 x 0.76-0.87 mm, longer than wide with length/width ratio (1.22-) 1.28 (- 1.34), barely decurrent with decurrent portion 0.06-0.08 mm long (5-7% of total leaf length); acumen 0.40-0.75 mm long, (43-) 52 (-56) % of leaf length measured from point of insertion; margins erect to plane or narrowly reflexed; costa single, well-developed but relatively slender, 0.67- 0.71 mm long, 33-46 urn wide at base; intramarginal cells elongate, 20.6-26.8 x 8.9-12.0 urn; midlaminar cells 21.6- 28.5 x 4.2-4.7 urn. Stipe leaves 0.93-1.44 x 0.69-1.01 mm; acumen 0.47-0.76 mm long. Representative specimens examined. ARGENTINA. NEUQUEN: Depto. Los Lagos, Isla Victoria (Lago Nahuel Huapi) , 820m, 21 Jan 1950, Sleumer 1712 (B) . RIO NEGRO: Puerto Blest, 21 Dec 1944, Mever 7348 (FH) . CHILE. AISEN: Patagonia occidentalis, Puerto Chacabuco, truncis d'arbores, 1908, Halle 840 (H, S, UPS); Puerto Aysen [Aisen] , Laguna de San Rafael, 2 Jan 1959, Pizzaro 6435 (NY). CHILOE: Isla Chiloe, Cordillera San Pedro, near aserradera at San Pedro, 42°25'S, 73°50IW, well- shaded forest on steep slope along rio Puidi, terrestrial, 320m, 5 Feb 1976, Crosby 12454 (MO) ; Patagonia occidentalis, Isles Guaitecas, Isla Westroff pa marken ruttna stockar, 20 Apr 1897, Pus en 623 (JE, S) . LLANQUIHUE: Zwischen Petrojue 180 [Petrohue] iiber Ensenada (Lago Todos Santos), 2 Mar 1927, Schiller 34 (JE) . VALDIVIA: Forest at Fundo Santa Rosa, 8 km by road N of Puente Callecalle, 39°44IS, 73°14'W, on rotting log, 0m, 16 Feb 1976, Crosby 12736 (MO) ; Depto. La Union, La Gualleria (Hualle-Huapi) , temperate rain forest, on trunks, 700m, 24 Dec 1947, Sparre 3714 (FH, S) ; Corral, 1905-06, Thaxter 83 (FH, FLAS, MICH, NY). Rigodium brachypodium var. tamarix has a distribution (ca 39°S to 48°S; Fig. 39) syrapatric with and restricted to the central range of R. brachypodium var. brachypodium (Fig. 37) . Nineteen collections (34 specimens) of this variety have been identified from the loan material. The stem leaves of R. brachypodium var. tamarix. longer than wide with a long acumen, express the ancestral leaf shape (weakly decurrent; Fig. 38B) . This morphology is similar to that of R. toxarion and is also exhibited under certain conditions by R. brachypodium var. brachypodium (see discussion above) . The stem leaves of R. brachypodium var. tamarix are consistently spreading to sguarrose, although Robinson (1975) describes them as "more appressed, nearly sheathing." Rigodium brachypodium var. tamarix and R. brachypodium var. brachypodium share the derived feature of the well- developed intramarginal band of cells (Fig. 38C) ; the species itself may be defined by the strongly prorulose midlaminar cells with the end walls projecting as papillae (prorulae) . Rigodium brachypodium var. tamarix is further 181 defined by the autapomorphy of the loss of the arborescent habit and the development of elongated, sprawling stems with ± regular pinnate branching (Fig. 38A) , which is unigue among Rigodium species. Curiously, this unusual branching pattern was not noted by Miiller (1897b) , the original author, but was emphasized by later bryologists such as Theriot (1934) and Robinson (1975). FIG. 34. Riqodium brachypodium var. brachypodium; Gametophytic Features. A. Habit. B. Portion of stem showing position of leaves. C. Stipe leaf. D. Stem leaf. E. Branch leaf. F-G. Stem leaves from two specimens showing variation in size. H. Cross section of stem leaf. I-J. Areolation of leaf. I. Midlaminar cells (note projecting end walls) . J. Marginal and intramarginal cells. A-E from Elliott 139 (H) ; F from Bertero s.n. (BM, lectotype R. brachypodium^ ; G from Dusen 482 (0) ; H-J from Crosby 12992 (MO) . 183 )clp0oocf00000oooo oooooOO' I W! N\ VaW A 40>jm U- mmmmmmk FIG. 35. Riqodium brachypodium var. brachypodium; Sporophytic and Related Gametophytic Features. A. Perichaetial leaf. B-C. Areolation of perichaetial leaf. B. Basal cells. C. Upper cells. D. Primary branch with perigonia. E. Perigonium. F. Perigonial leaves. G. Capsule. A-C from Crosby 12992 (MO) ; D-G from Lechler 629 (MICH, isolectotype R. arborescens) . 185 FIG. 36. Rigodium brachypodium var. brachypodium: Stem leaves with Long Acumens. A. Leaf from elongate stem rooting at the tips (other stem leaves with short acumens) . B. Stem leaf from unusual specimen of this species (see text for discussion) . A from Lechler 629 (W, isolectotype R. arborescens) ; B from Hollermayer 281 p.p. (S) . 187 0.3mm FIG. 37. Distribution of Rigodium brachypodium var. brachypodium. 189 Distribution of B. brachypodium var. brachypodium ISLA JUAN FERNANDEZ 35 •Q- 1 33° 45- 33° 45* 10km j S3 80°45' 79° 0' *%<• SOUTHERN CHILE AND ARGENTINA 300km FIG« 38. Riaodium brachvpodium var. tamarix. A. Habit. B. Stem leaf. C-D. Areolation of stem leaf. C. Marginal and intramarginal cells. D. Midlaminar cells. All from Crosby 12613 (MO) . 191 "*Sk> FIG. 39. Distribution of Rigodium brachypodium var. tamarix. 193 Distribution of R. brachypodium var. tamarix *$* SOUTHERN CHILE AND ARGENTINA r- 0 300km 194 3. Riqodium adpressum Zomlefer. sp. nov. Riqodium adpressum Zomlefer, Syst. Bot. 17(1): (in press). Figs. 2-3, 1992. Types: Argentina. Chubut: Lago Menendez, 1 Dec 1940, Kuhnemann 5260 (holotype: Hi; isotypes: ALTAI, U!) Plants medium to large, dendroid, erect or more commonly pendent, irregularly pinnately branched, on tree trunks and branches, sometimes on logs or rarely on rocks, green, yellow-green to yellowish brown, rarely rooting at tips of stems and primary branches. Stipes well-developed, to 2.5 cm long. Stems to 3.8 (-4.7) cm long, 270-480 urn in diameter. Primary branches generally 10-20 per stem, spaced 1.0-2.5 mm apart along the stem, proximal ones to 2.2 cm long, gradually becoming much shorter above, occasionally attenuate. Secondary branches generally 8-2 0 per primary branch, to 0.9 cm long. Tertiary branches present. Stem leaves ovate at base and abruptly narrowed to a well- developed acumen, + subulate, 0.68-1.21 x 0.50-0.78 mm, ca longer than wide with length/width ratio (1. 23-) 1. 41 (-1. 56) , strongly appressed with + spreading-erect tips, with clasping and concave base, auriculate, strongly decurrent with decurrent portion 0.20-0.26 mm long (14-22% of total leaf length) and with some cells of decurrency with a central papilla; acumen 0.33-0.64 mm long, (32-) 39 (-43) % of leaf length measured from point of insertion; margins strongly revolute, + entire or sinuous at base and serrate 195 above; costa single, well-developed, 0.61-1.33 mm long, 41- 62 urn wide at base, 2-3-stratose in lower half; alar cells guadrate to oblate, 6.3-11.7 x 7.7-11.1 urn; marginal cells 1-2-seriate, oblong-rhombic, 10.7-17.7 x 3.6-5.3 um; intramarginal cells (4-) 5-6-seriate, short-oblong, 18.0-21.0 x 7.7-11.3 um, with much thicker walls than the midlaminar cells and forming a very strong intramarginal band; midlaminar cells rhombic to rhomboidal, 22.1-32.2 x 3.8-6.2 um, porose with walls very uneven, prorulose. Stipe leaves with similar shape and orientation as stem leaves, 0.68-1.21 x 0.50-0.78 mm; acumen 0.29-0.52 mm long; costa absent or rarely single and then very weak. Secondary branch leaves narrowly ovate, acute, 0.32-0.45 x 0.16-0.27 mm, with length/width ratio (1. 61-) 2 . 02 (-2 . 26) , appressed to erect, often decurrent; margins strongly revolute, serrate. Perigonial leaves ovate, acute to shortly acuminate, 0.66- 0.74 x 0.30-0.34 mm. Antheridia 250-275 x 100-140 um; paraphyses 8-9 cells long, 310-540 um long. Perichaetial leaves subulate, 1.35-2.47 x 0.49-0.82 mm, long-acuminate with acumens 0.34-0.54 mm long; basal cells rhomboidal, 37.3-57.3 x 8.3-10.7 um, porose, prorulose, freguently papillose with one large central papilla; apical cells rhombic, + sinuous, 18.7-28.0 x 4.0-6.0 um. Archeaonia 340- 500 um long, 38-55 wide at venter; paraphyses 11-19 cells long, 390-620 um. Seta to 1.5 cm long. Capsule urn 1.60- 1.80 x 0.60 mm; upper exothecial cells 13.0-20.2 x 13.0-15.0 um; median exothecial cells 63.3-65.0 x 30.0-35.0; cells in 196 neck 40.0-45.0 x 10.0-12.3. Operculum 0.92 mm long, long- rostrate with beak 0.56 mm long (only 1 intact operculum seen) . Exostome teeth 650-710 urn long, 85-95 urn wide at base. Endostome segments 310-350 urn long, 40-50 urn wide at base; basal membrane 190-240 urn high; cilia 2-3, 240-290 um long. Spores 18-2 0 um in diameter. Calyptra to 1.8 mm long. Representative specimens examined. ARGENTINA. CHUBUT: SW arm of Lago Menendez, SE slope, Nothofaqus dombeyi forest, 20 Jan 1938, Kalela B246h (H) ; Lago Rivadavia, 13 Dec 1940, Kiihnemann 5195 (ALTA, U) . NEUQUEN: Lago Correntoso, steep slope by brook running through isthmus between Lago Correntoso and Lago Espejo, Nothofaqus dombeyi forest, 9 Nov 1937, Kalela B28n (H) ; Pargue Nacional Lanin, Peninsula de Pucara, 3 Feb 1969, Matteri 432 (BA) . RIO NEGRO: Parque Nacional Argentino [Pargue Nacional Nahuel Huapi], Nahuel Huapi, Puerto Panuelo, 800 m, 13 Jun 1936, Donat 2 (JE) ; Lago Mascardi, slope above lake, ca 5-6 km N of El Maitenal, Nothofaqus dombeyi forest with Austrocedrus . 9 Dec 1937, Kalela B136q (H) . SANTA CRUZ: S end of Lago Argentina, W side of Laguna Fria, 51°S, 73 °W, mature forest dominated by Nothofaqus pumilio with N. betuloides and N. antarctica, 15-18 Mar 1972, Cantino M-ll. M-17 . M-35 (all MO) ; Depto. Lago Argentino, Bahia Ameghino al N del rio (refugio) , bosque mixto de Nothofaqus betuloides. N. pumilio. Drimys winteri, Mavtenus magellanica. M. disticha y 197 abundancia de helechos, 50°24*S, 73°15'W, 30 Jan 1988, Matteri & Schiavone 4985 (Herb. Matteri) . CHILE. AISEN: Patagonia occidentalis, rio Aysen [Aisen] , in truncis, 5 Jan 1897, Dusen 397 (CHR, DUKE, FH, FLAS, GB, NY, S) . CAUTIN: Depto. Villarrica, Pucon, auf dem Weg nach deiri Vulcan Villarrica, auf Baumen, 8 Feb 1935, Hosseus 226 (JE) ; Parque Nacional Conguillio, al S de la Laguna en el roquerio f rente las Cabanas, 1110 m, 6 Feb 1976, Mahu 10733 (MO) ; Volcan Llaima, auf morschen Baumstammen , 1080 m, 15 Feb 1966, Ruthsatz s.n. (H) . MAGALLANES: Puerto Arturo, no date, Benove 64 (H) ; Puerto Arturo, sobre arbol putrido, 3 Mar 1922, Benove 65 (H) . MALLECO: Depto. Angol, Estero Aguas Calientes, Parque Nacional de Nahuelbuta, frente a casa de Pincheira, 1250 m, 1 Apr 1971, Mahu 6076 (FLAS) . MALLECO/ ARAUCO : Parque Nacional Nahuelbuta, Cordillera Nahuelbuta, 6.3 km W of park entrance, 44 km W of Angol, 37°46'S, 73o00'W, Nothofaaus forest, on rock, 1300 m, 26 Feb 1976, Crosby 13093 (MO) . NUBLE: Recinto, Las Francas, el Purgatorio, in silva Nothofacms dombeyi . 1200 m, 12 Apr 1929, Roivainen 1597 (FH, H) . VALDIVIA: Cordillera Pelada [La Pelada] , Mischwald, auf Baumrinde, 780 m, Jan 1966, Ruthsatz s.n. (H) . VALDIVIA/ ORSONO : Forest reserve at Planta Hidroelectrica Pilmaiquen, 2 km W of Entre Lagos, along rio Pilmaiquen, near top of Salto Brujo, 40°40'S, 72°40fW, on tree, some stems pendent, 100 m, 29 Jan 1976, Crosby 12210 (MO) . 198 Rigodium adpressum is usually epiphytic on tree trunks and branches (also sometimes occurring on logs and rocks) in forests dominated by Nothofagus species (with Mvrceugenia . Austrocedrus, Drimys. and Maytenus) . The elevation is usually 800 to 1200 m, although lower altitudes (100 m) are occasionally cited on the specimen labels. The range, along the Andean Cordillera in Chile-Argentina, extends from ca 37°S to 53°S (Fig. 42) . Thirty-one collections (45 specimens) of R. adpressum have been determined from the loan material (Zomlefer, 1992). It is somewhat surprising that a distinct (i.e., numerous autapomorphies) and well-collected species had been overlooked by previous authors, considering the abundance of Rigodium species descriptions and the number of epithets reduced in synonymy in this revision (see Table 1) . The majority of the R. adpressum specimens had not been identified to species; the remainder had been labelled as R. toxarion. R. nano-fasciculatum (= R. toxarion in the present study) or R. arborescens (= R. brachypodium in the present study) . Rigodium adpressum is phenetically close to R. brachypodium var. brachypodium and R. toxarion var. toxarion. as shown graphically in the results of the PC analysis (Fig. 24A and B) . All three species share the plesiomorphic character of the arborescent habit with a well-developed stipe (Fig. 40A) . In addition, the new species and R. brachypodium both have obvious intramarginal borders (derived character) on 199 the stem and stipe leaves. Riqodium adpressum stem leaves, which are longer than wide (Fig. 19D) , are somewhat similar in shape to those of R. toxarion. The appressed position (Fig. 40B) of the stem and stipe leaves of R. adpressum. however, is very unlike that of other Riqodium species, which are wide-spreading to squarrose. Also easily discernible with the dissecting microscope at low power (Fig. 40B) are the strongly revolute leaf margins (Fig. 40H) , compared to the plane to weakly reflexed condition of the other species. In addition, the cells of the intramarginal band (Fig. 401) have extremely thick walls and are much shorter than the midlaminar cells, another autapomorphy for the species (see Fig. 19C) . The stem, stipe, and sometimes branch leaves of the new species have the additional autapomorphic feature of a long decurrency (over 14% of the total leaf length; Figs. 19B, 40C and D) . Several cells of the decurrent portion contain a large, low, central papilla (Fig. 40G) on the dorsal side. As noted in the chapter on general morphology, similar papillae are occasionally to frequently present at the base of the outer perichaetial leaves in all Riqodium species, but occur consistently on all the available collections of R. adpressum with archegonial plants (Fig. 4 IB and C) . As discussed in detail in the cladistic analysis (Figs. 20 and 21) , R. adpressum is phylogenetically intermediate within the genus, although the exact relationship of R. adpressum to the other species is unclear. The new species 200 may be positioned between R. brachypodium and the R. implexum/R. pseudo-thuidium clade (see Fig. 20) , if R. brachypodium is paraphyletic, or R. adpressum may possibly be less derived than R. brachypodium. if the latter species is monophyletic (Fig. 21A) . Minor variants of the new species are found in the collections of Crosby 12210 and Dusen 397 , which generally exhibit the distinguishing characters of R. adpressum but have weakly spreading leaves. In addition, as noted for R. toxarion and R. adpressum (both also arborescent) , a few collections of R. adpressum feature a lax, sparsely branched habit (e.g., Hosseus 163 [Zomlefer a] ) . probably due to less than optimal environmental conditions. FIG. 40. Rigodium adpressum; Gametophytic Features. A. Habit. B. Portion of stem. C. Stipe leaf. D. Stem leaf. E. Branch leaves. F. Cross section of stem taken at location indicated by arrow in B (i.e., through decurrent portion of stem leaf) . G-J. Areolation of leaf. G. Cells of basal decurrency. H. Cross section of stem leaf. I. Marginal and intramarginal cells. J. Midlaminar cells. All from Kiihnemann 5260 (ALTA, isotype) . 202 FIG. 41. Ricrodium adpressum: Sporophytic and Related Gametophytic Features. A. Perichaetial leaf. B. Basal areolation of perichaetial leaf. C. Cross section of perichaetial leaf taken near base. D. Areolation of upper perichaetial leaf. E. Branch with perigonia. F. Perigonium. G. Outer perigonial leaf. H. Inner perigonial leaf. I. Operculate capsule (rostrum broken). J. Detached operculum. K. Deoperculate capsule. A-D: Kuhnemann 5260 (ALTA, isotype) . E-H: Ruthsatz s.n. , Volcan Llaima (H) . I and K: Matteri & Schiavone 4985 (Herb. Matteri) . J: Dusen 397 (NY) . 204 0.5mm FIG. 42. Distribution of Riqodium adpressum. 206 Distribution of R. adpressurn *h* SOUTHERN CHILE AND ARGENTINA i i 1 0 300km 207 4. Rigodium implexum Kunze ex Schwagr. Rigodium implexum Kunze ex Schwagr., Linnaea 18: 559. Plate 9. 1844 [1845]. Hypnum implexum (Schwaegr.) C. Mull., Linnaea 18: 676. 1844 [1845]. Heterocladium implexum (Schwagr.) Lor., Bot. Zeit. 24: 189. 1866. Type: Chile. Bio-Bio: Chile australis, Andes de Antuco, in sylvis densis, Dec 1828, Poeppiq s.n. (lectotype: BM!); Chile australis, Andes de Antuco, no date, Poeppiq s.n. (original material, FH!); Chile. 1829, Poeppiq s.n. (original material, BM!); Chile. no date, Poeppiq s.n. (original material, BM!); Chile. no date, Poeppiq s.n. (original material, JE!); lectotypif ication in Zomlefer (1990) . Plants medium to large, extremely wiry, often forming large tangled and unattached mats, profusely irregularly pinnately branched with primary and secondary branches at wide angles to the stems, usually on soil or occasionally on tree trunks or branches, dark green to brownish green. Stipes not well-differentiated, to 0.5 cm long. Stems to 6.1 cm long, 330-615 um in diameter. Primary branches generally 15-30 per stem, spaced 3.0-4.0 mm apart along the stem, proximal ones to 4.0 cm long, gradually becoming much shorter above. Secondary branches generally 10-20 per primary branch, to 3.0 cm long. Tertiary branches present, profuse. Stem leaves broadly ovate at base and abruptly narrowed to a well-developed acumen, 0.68-1.20 x 0.72-1.11 208 mm, ca as long as wide with length/width ratio (0. 95-) 1.05 (-1.14), strongly squarrose, with clasping and concave base, longitudinally undulate, occasionally auriculate, somewhat decurrent with decurrent portion 0.06-0.11 mm long [(7-)8- 11% of total leaf length]; acumen 0.23-0.55 mm long, (33-) 39 (-46)% of leaf length measured from point of insertion; margins plane to weakly reflexed, serrate throughout; costa single, relatively well-developed, 0.51-0.89 mm long, 58-66 um wide at base, (3-) 4-5-stratose in lower half; alar cells quadrate to oblate, 6.6-12.4 x 6.4-10.3 um; marginal cells 1-2 -seriate, oblong -rhombic, 13.9-18.9 x 4.1-7.3 um; intramarginal cells (7-) 8-9 (-10) -seriate, oblong to elongate, 20.5-25.8 x 7.3-10.7 um, with thicker walls than the midlaminar cells and forming a moderately strong intramarginal band; midlaminar cells rhombic to rhomboidal, 21.1-28.5 x 3.6-6.7 um, porose with walls + uneven, + prorulose. Stipe leaves with similar shape and orientation as stem leaves, 0.59-0.81 x 0.71-0.92 mm; acumen 0.12-0.36 mm long; costa absent. Secondary branch leaves narrowly ovate, acute, 0.33-0.48 x 0.25-0.32 mm, with length/width ratio (1.22-) 1.45(-1.68) , spreading to squarrose; margins serrate. Perigonial leaves ovate, acute to shortly acuminate, 0.49-0.65 x 0.21-0.30 mm. Antheridia 380-410 x 100-110 um; paraphyses 9-12 cells long, 410-425 um long. Perichaetial leaves subulate, 1.31-1.92 x 0.45-0.77 mm, long-acuminate with acumens 0.3 5-0.51 mm long; basal cells rhomboidal, 42.0-74.7 x 7.7-12.0 um, porose, prorulose, 209 sometimes papillose with one large central papilla; apical cells rhombic, + sinuous, 20.3-28.0 x 3.0-7.0 urn. Archegonia 380-560 um long, 40-50 wide at venter; paraphyses 10-16 cells long, 475-620 um. Seta to 2.0 cm long. Capsule urn 1.37-1.80 x 0.50-0.73 mm; upper exothecial cells 18.3- 25.0 x 19.0-21.7 um; median exothecial cells 46.7-63.3 x 23.3-35.0; cells in neck 27.3-40.0 x 11.3-17.0. Operculum 0.60-0.80 mm long, long-rostrate with beak 0.30-0.45 mm long. Exostome teeth 645-718 um long, 110-127 um wide at base. Endostome segments 325-385 um long, 45-65 um wide at base; basal membrane 210-240 um high; cilia 2-3, 180-225 um long. Spores 17-20 um in diameter. Calyptra to 2.5 mm long. Representative specimens examined. ARGENTINA. NEUQUEN: Parque Nacional Lanin, Pucara, bosque de Nothofagus nervosa y N. dombeyi . en el suelo, May 1966, Eskuche 941-13 (H) ; Lago Correntoso, on road to hotel, Nothofacrus dombeyi forest, 6 Nov 1937, Kalela B4c (H) . CHILE. AISEN: Patagonia occidentalis in valle fluminis Aysen [Aisen] in terra, 5 Jan 1897, Dusen 409 (BM, CHR, DUIS, FH, H, JE, M, MICH, NY, O, S, UPS, W) ; Patagonia occidentalis, Canal Moraledas [Moraleda Canal], Puerto Chacabuco, ad terrain, 7 Jul 1908, Halle 837 (H, S, UPS). CAUTIN: Depto. Villarrica, Pucon, auf dem Weg nach dem Vulkan Villarrica, auf Erde, 8 Feb 1935, C^ Hosseus 235 (FH, JE, M) . CHILOE: Isla Chiloe, forest at Chadmo Central, just N of Puente San Juan along Ruta 5, 2 0.9 km by road N of 210 Quellon, 42057'S, 73'46'W, terrestrial, not attached to substrate, 50m, 6 Feb 1976, Crosby 12504 (ALTA, CANM, CHR, FLAS, H, KRAM, MICH, MO, NY, S, U) ; Chepu, Nothofaaus nitida forest, free-living on forest floor, 3 Oct 1958, Godley 105 (BM, CHR, FLAS, H) . CONCEPCION: Talcahuano, 30 Jul 1921, Asplund 62 (S) . LLANQUIHUE : Yerbas Buenas, Centro de Recreacion Las Cascadas, al Este de Las Cabanas, 41°07'S, 72°36,11MW, bosque de Nothofaaus dombeyi . en suelo sobre hierbas y hojarasca, 20m, 18 Jan 1986, Mahu & Tapia 21333 (MO); Roblewald bei Corte Alto, siidlich von Osorno, 1958, Oberdorfer 178a (JE) . MALLECO: Chile australis in monte "Cordillera de la Costa" supra Angol oppidam, in terra, 5 Nov 1896, Dusen 356 (B, FH, GB, JE, O, S, W) ; Cordillera de Nahuelbuta, on ground in Araucaria-Nothofaaus forest, 1100- 1300m, 6 Apr 1948, Sparre 5065 (S) . OSORNO: Near province Valdivia boundary, Anticura, vicinity of Salto del Indio, 19 km by road E of Termas de Puyehue along international highway, 40o39'S, 72°10'W, in forest, terrestrial, not attached to substrate, 300m, 30 Jan 1976, Crosby 12295 (FLAS, L, MICH, MO, NY) ; Salto de Pilmaiquen, on ground in shadowy forest, 13 Feb 1948, Sparre 4465 (S) . VALDIVIA: 1 mi E of point where rio Bueno leaves Lago Ranco, 40°S, 72 °W, loose on forest floor like tiny tumbleweeds, 11 Feb 1972, Cantino 71 (MO) ; Isla Teja, W of Parque de Exposiciones Saval, 39°48S, 73 "16'W, low mucky stream-cut area, dense shrubs, terrestrial, 0m, 11 Jan 1976, Crosby 11565 (FLAS, MO); Corral, pa stenar vid backar, 5 Jun 1896, Dusen 75 (H, 211 S) ; Prope coloniam Arique, ad terrain, Aug no year, Lechler 620a (BM, BR, G, H, L, NY, 0, OXF, S, UPS, W) . Riqodium implexum generally occurs on well-shaded, damp to swampy ground in forests dominated by species of Nothofaqus (along with Araucaria, Laurel ia. Weinmannia, Chusquea. and Eucryphia) at altitudes usually reported at 0 to 400 m, although higher elevations (800 to 1300 m) are sometimes cited on the labels. The range (Fig. 45), ca 37°S to 47°S (along the Andean Cordillera in Chile-Argentina), is the most restricted of the Riqodium species. Riqodium implexum is one of the most common mosses in the Valdivian rainforests (Herzog, 1939) . Besides Valdivia, the species has been collected extensively in the provinces of Cautin and Llanquihue, as well as on the island of Chiloe. The genus Riqodium was first described by Schwagrichen (1844) with specimens of R. implexum as the type(s). The situation concerning the original material, nomenclature, and lectotypification of R. implexum is discussed in detail in Zomlefer (1990) . Due to confusion in the literature concerning the epithets of Riqodium, herbarium specimens of R. implexum are often labelled as "R. toxarion. " the oldest epithet in the genus. The species, however, is one of the easiest in the genus to identify due to the unusual and derived habit type (Fig. 4 3A) . The extremely wiry stems and branches (of all orders) arise at right angles and spread in all directions (Herzog, 1939) , eventually forming 212 unattached, irregularly "spherical masses" (Middleton s.n. ; Crosby 12057) , also described by collectors as "Kugeln" ("globes" or "spheres," Sleumer 1733.), "Halbkugeln" ("hemispheres," Poeppig s.n.), "sponge-like masses" (Middleton s.n.), "tiny tumbleweeds" (Canting 71) . and "lana de pobre" ("poor man's wool;" Herzog, 1939; Schwabe 80; Crosby 12504) . Although most commonly terrestrial and unattached to the substrate, the species is also rarely reported growing as an epiphyte on low branches. With R. pseudo-thuidium , R. implexum is phylogenetically advanced within Rigodium, sharing the four following derived characters with its sister species (Figs. 20, 21) : loss of rooting at the tips of branches (a reversal) , loss of well-developed stipe, spreading branches that arise at right angles to the stems (discussed above) , and a well-developed intramarginal band. The stem leaves of both species also tend to be ca as long as wide (Fig. 19D) with short acumens (19E) . The intramarginal band (Fig. 43F and H) consists of up to ten rows of cells that are usually longer than those of the midlaminar region (Fig. 19C) . The midlaminar cells (Fig. 43G) have uneven walls and are prorulose, but not to the same extent as R. pseudo-thuidium . As noted by several authors (Brotherus, 1925; Robinson, 1975) , the stem leaves of R. implexum are strongly squarrose, wet or dry (Fig. 43B) . In addition, the costae of R. implexum stem leaves tend to be well-differentiated, 213 4- to 5-stratose in the lower half (Fig. 43F) , as opposed to 2- to 3-stratose (or absent) in other species of Ricrodium. FIG. 43. Rigodium implexum: Garnet ophy tic Features. A. Habit. B. Portion of stem showing position of leaves. C. "Stipe" (low stem) leaf. D. Stem leaf. E. Branch leaf. F. Cross section of leaf. G-H. Areolation of leaf. G. Midlaminar cells. H. Marginal and intramarginal cells. A from Dusen 409 (O) ; B-H from Claude-Joseph 2775 (FH) . 215 FIG. 44. Rigodium implexum; Sporophytic and Related Garnet ophy tic Features. A. Perichaetial leaf. B-C. Areolation of perichaetial leaf. B. Basal cells. C. Upper cells. D. Secondary branch with perigonia. E. Perigonium. F. Perigonial leaves. G. Stem with sporophytes. H. Capsule. A-C, G, H from Claude-Joseph 2775 (FH) ; D-F from Crosby 12057 (UPS) . 217 0.3mm FIG. 45. Distribution of Rigodium implexum. Distribution of R. implexum 219 fh* SOUTHERN CHILE AND ARGENTINA r- 0 300km 220 5. Riqodium pseudo-thuidium Pus. Riqodium pseudo-thuidium Dus., Bot. Not. 1905: 310. 1905. Types: Chile. Aisen: Patagonia occidentale, in valle fluminis Aysen [Aisen] in terra, 26 Jan 1897, Dusen 481 (lectotype: S ! ; isolectotypes: BM! , CHR! , FH (2 specimens)!, FLAS!, JE! , M! , NY (2 specimens)!, 0!, S (5 specimens)!, UPS!, W! ) ; Chile: Magallanes: Fuegia, Port Gallant [Puerto Gallant], in terra, 20 Mar 1896, Dusen 350 (original material: M! , S!, UPS!); Tierra del Fuego, Fuegia austral is, rio Azopardo, in terra, 1 Mar 1896, Dusen 196 (original material: CHR!, H! , S (2 specimens)!, UPS!, W (2 specimens)!); Fuegia australis, cerre de tere, rio Azopardo, in truncis arborum, in humo, 2 Feb 1896, Dusen 206 (original material: CHR!, FH!, H! , JE!, L! , S (2 specimens)!, UPS!); lectotypification in Zomlefer (1991). Riqodium hylocomioides Card. & Broth. , Bih. K. Svensk. Vet. Ak. Handl. 63(10): 69. Plate III, Figs. 15a-c. 1923. Types: Chile. Magallanes: Fuegia, Almirantazgo [Seno del Almirantazgo], Hope Bay, in dumetris, 3 Feb 1908, Halle & Skottsberg 842 (lectotype here designated: PC! ; isolectotypes: S!, UPS!); Patagonia australis, Skyring [Lake Skyring], Puerto Pinto, forets a feuilles persistantes, 23 Apr 1908, Halle &. Skottsberg 841 (syntypes: BM! , JE!, PC!, S!, UPS!, W! ; possible syntype as s.n. : S!); Fretum magellanicum [Strait of 221 Magellan], Isla Dawson, Harris Bay, 25 Feb 1908, Skottsberq 843 (syntypes: PC!, UPS!). Riqodium hylocomioides var. qracilius Card. & Broth., Bih. K. Svensk. Vet. Ak. Handl. 63(10): 69. 1923. Types: Chile. Chiloe: Islas Guaitecas, Melinca, ad truncos, 1 Aug 1908, Halle 844 (lectotype here designated: PC!; isolectotypes: S!, UPS!); Chile. Magallanes: Patagonia occidentale, Smyth Channel, O'Connor Cove, etait milangi Acrocladium auriculatum, 25 Jun 1908, Halle 845 (syntype: UPS! ) . Plants medium to large, little branched (once to twice pinnate) , pendent or creeping, on tree trunks and branches or occasionally on logs, rocks, or soil, green or more commonly yellow-green to yellowish brown. Stipes not well- differentiated, to 0.7 cm long. Stems to 13.0 cm long, 320- 750 urn in diameter. Primary branches generally 25-35 (-60) per stem, spaced 3 . 0-6. 0 (-10. 0) mm apart along the stem, proximal ones to 2.6 cm long, not becoming noticeably shorter above, recurved. Secondary branches generally 3- 10 (-15) per primary branch, to 1.4 cm long. Tertiary branches rarely present. Stem leaves broadly ovate at base and abruptly narrowed to a short acumen, 0.84-1.22 x 0.85- 1.31 mm, ca shorter than wide with length/width ratio (0. 76-) 0.93 (-1.21) , spreading to squarrose, with broad clasping and concave base, strongly longitudinally undulate, auriculate, somewhat decurrent with decurrent portion 0.09- 222 0.14 mm long (9-12% of total leaf length); acumen 0.17-0.43 mm long, (21-) 34 (-46) % of leaf length measured from point of insertion; margins reflexed, serrate throughout; costa absent or occasionally present (then very weak or double) ; alar cells quadrate to oblate, 7.7-14.3 x 5.7-12.2 um; marginal cells 1-2-seriate, oblong-rhombic, 14.3-28.9 x 3.6- 6.9 um; intramarginal cells (7-) 8-9 (-10) -seriate, oblong to elongate, 17.2-31.4 x 4.9-10.9 um, with thicker walls than the midlaminar cells and forming a strong intramarginal band; midlaminar cells rhombic to rhomboidal, 24.6-40.9 x 4.1-6.4 um, porose with walls very uneven, very prorulose. Stipe leaves with similar shape and orientation as stem leaves, 0.69-1.13 x 0.83-1.20 mm; acumen 0.20-0.53 mm long; costa absent. Secondary branch leaves broadly ovate to ovate, acute, 0.38-0.69 x 0.27-0.44 mm, with length/width ratio (1. 03-) 1.67 (-2.06) , erect-spreading to spreading; margins serrate; costa often weak. Perigonial leaves broadly ovate, acute to shortly acuminate, 0.74-0.82 x 0.31- 0.35 mm. Antheridia 300-360 x 65-90 um; paraphyses 9-10 cells long, 400-475 um long. Perichaetial leaves subulate, 1.38-2.39 x 0.47-0.80 mm, long-acuminate with acumens 0.28- 0.59 mm long; basal cells rhomboidal, 33.3-64.7 x 5.8-11.7 um, porose, very prorulose, sometimes papillose with one large central papilla; apical cells rhombic, + sinuous, 14.7-41.0 x 3.0-5.0 um. Archegonia 425-560 um long, 40-60 wide at venter; paraphyses 13-17 cells long, 490-720 um. Seta to 2.4 cm long. Capsule urn 1.45-1.90 x 0.47-0.95 mm; 223 upper exothecial cells 17.0-21.0 x 19.3-21.7 um; median exothecial cells 36.7-53.0 x 22.0-41.7; cells in neck 20.0- 30.0 x 10.7-13.3. Operculum not seen. Exostome teeth 565- 718 um long, 107-113 um wide at base. Endostome segments 257-333 um long, 45-60 um wide at base; basal membrane 212- 290 um high; cilia 2-3, 215-270 um long. Spores 18-20 um in diameter. Calyptra to 3.5 mm long. Representative specimens examined. ARGENTINA. NEUQUEN: Lago Espejo, 0.5 km towards Correntoso from the park warden's residence, on top of small hill, 8 Nov 1937, Kalela B14f (H) ; Lago Espejo, N of campsite, on steep slope, 10 Nov 1937, Kalela B30a (H) . RIO NEGRO: Lago Mascardi, on very gentle slope above lake ca 3 km S of Hotel Tronador, Nothofagus dombeyi-Austrocedrus forest, 8 Dec 1937, Kalela B125e (H) ; Lago Nahuel Huapi, excursion von Campamento II, 6 May 1933, Liunaner 1315 (JE, S) . SANTA CRUZ: Santa Cruz (Patagonien) , an Quellen, no date, Hicken s.n. (JE) . TIERRA DEL FUEGO: Bahia Buen Suceso, en turbera de Sphagnum magellanicum sobre la costa Sur del rio Bove, 54°48,S, eS'lS'W, 18 Jan? 1986, Matteri & Schiavone 3525 (Herb. Matteri) ; Isla de los Estados, B. Liberty, forest floor near sea coast, 2 Nov 1971, Matteri 1501 (Herb. Matteri). CHILE. AISEN: Patagonia occidentalis, rio Aysen [Aisen], in truncis arborum, 15 Jan 1897, Pus en 417 (GB, S) ; Patagonien, Punta Lagunas N Ultima Esperanza [Canal], 22 Apr 1924, Gusinde 4492 (B, BM, BR, C, F, G, GB, H, KRAM, L, M, O, S, W) ; Puerto Aysen [Aisen], 28 Feb 1934, Vergara 2917 224 (G) . CAUTIN: Parque Nacional Villarrica, north slope of Volcan Villarrica very near upper limit of forest and Refugio Villarrica, 6.1 km by road S of park entrance, 39022'S, 71°57,W, on tree base, 1150m, 19 Jan 1976, Crosby 11809 (FLAS, MO) ; Depto. Villarrica, Pucon, auf dem Weg nach dem Vulkan Villarrica, auf Baumen, 8 Feb 1935, C\_ Hosseus 33B (JE) . CHILOE: Patagonia occidentalis, in insulis Guaitecas, Melinca, in terra, 23 Apr 1897, Dusen 625 (BM, S, W) ; Peninsula Tres Montes, Puerto Barroso, in margine humido silvae sempervirantis, 2 Apr 1929, Roivainen 1595 (H) . JUAN FERNANDEZ ISLANDS: Isla Mas Afuera [Isla Alejandro Selkirk], below summit of Los Innocentes, open grassy glade among ferns, 1220m, 1 Dec 1965, Hatcher & Engel 235 (DUKE, FH, G, H, MICH). LLANQUIHUE: Along road to Calbuco, ca 30 km S of Puerto Montt, on stump in swampy forest of Podocarpus . Saxeqothaea . Drimys . and Nothofaaus. 50m, 17 Dec 1970, Landrum 465 (MO) ; Volcan Antillanca, Nothofaaus pumilio Wald an der Baumgrenze, am Fuss der Baume, 118 0m, 18 Feb 1966, Ruthsatz s.n. (H) . MAGALLANES: Fuegia occidentalis, Insula Desolacion [Isla Desolacion], Puerto Angusto [Angosto] , 6 Apr 1896, Dusen 329 (GB, S, UPS); Seno Ultima Esperanza, 51°35'S, 73o20'W, Fuchsia maqellanica community, 1965-6, Tsudqii & Yoshida 844 (H) . MALLECO: Chile australis in monte Cordillera de la Costa supra Angol, terricola, 1896-97, Dusen 235 TZomlefer bl (BM, F, FH, JE, L, MANCH, MO, S, W) . 0S0RN0: Agua Calientes, en el Parque Nacional Puyehue, sobre corteza, 10 Jan 1979, Barrandeauy 225 345 (MO) ; Huitrapulli-Aleucapi, an Boden iiber Stammen, 820- 700m, Mar 1958, Herzog 28 TZomlefer b] (JE) . VALDIVIA: Volcan Quetrupillan, Forestal Trafan, forest on SW slope, 39°34'S, 71M7W, tree base, 1300m, 18 Jan 1976, Crosby 11761 (MO) ; Volcan Choshuenco [Shoshuenco] , Nothofagus pumilio Wald, auf Felsblocken und Erdboden, 1080m, 23 Feb 1966, Ruthsatz s.n. (H) . Rigodium pseudo-thuidium is mostly epiphytic on tree bases and branches, or much less commonly occurring on logs, rocks, or soil. The habitat varies from dense, wet to swampy forests (Nothofagus, Austrocedrus, Saxeqothaea. Drimys . and Podocarpus) to moist, open grassy or mossy areas that are sometimes disturbed. Of the few altitudes reported on the labels, most fall within the range of 700 to 1350 m, with a few reported at ca sea level (0 to 100 m) . The distribution (Fig. 48) of R. pseudo-thuidium extends from ca 38 °S along the Andean Cordillera (Chile-Argentina) throughout Patagonia to 55 "S, and east to Isla de los Estados, Argentina. Along with R. brachypodium, the species delimits the southernmost distribution of the genus. Rigodium pseudo-thuidium also occurs in the Juan Fernandez Islands on Isla Alejandro Selkirk (Isla Mas Afuera) , but not on Isla Robinson Crusoe (Isla Mas a Tierra) . Autapomorphies of the habit (reduced branching) and stem leaves (reduced costa) , discussed below, distinguish R. pseudo-thuidium . Although R. pseudo-thuidium has a 226 characteristic habit (Fig. 46A) , specimens have occasionally been misidentif ied as R. implexum (e.g., some specimens of Dusen 618 . Fig. 22B) due to stem-like branches (innovations) that sometimes arise from the stems, giving the specimen a somewhat superficial resemblance to R. implexum, its sister group. As discussed under R. implexum, the two species are the most derived in Rigodium (Figs. 20, 21) and are defined by several synapomorphies including right-angle branching and the lack of a well-developed stipe. However, unlike the profusion of branching in R. implexum, the orders of branching are very reduced in R. pseudo-thuidium (Fig. 4 6A) . Secondary branches are few (generally 3 to 10 per primary branch) and tertiary branching is rare. The stem leaves of R. pseudo-thuidium (Fig. 46C) , nearly always auriculate, are very broad at the base and terminate with a short acumen (ca one third of the leaf length) . As discussed under general morphology, the tendency for stem leaves to form auriculae is found in all species of Rigodium. but is most pronounced and consistent in R. pseudo-thuidium . Another outstanding feature of the stem leaves is the poorly developed costa (i.e., weak or double) . Although reported as strictly ecostate (Dusen, 1905) , even stem leaves which appear ecostate in surface view (Fig. 46C) show a trace of the costa in cross section (Fig. 46K) . Probably due to the lack of support (i.e., lack of costa) , the stem leaves are very strongly longitudinally undulate with strongly recurved tips (Fig. 46B) . The 227 intramarginal band is very broad (up to ten cells across; Fig. 46L) , and the cells tend to be generally much longer and wider than those of the midlaminar region (Fig. 19C) . Midlaminar cells of both stem and perichaetial leaves are extremely porose and prorulose (but end walls not projecting as dorsal papillae) . Branch leaves tend to be broader (up to 0.44 mm wide) than in the other species of Riqodium and often have weak costae as well. As supported by the PC analyses (Fig. 24A and B) , the sporophyte of R. pseudo- thuidium tends to be larger than those in the other species (e.g., capsule urn up to 1.9 x 0.95 mm). The concept of R. pseudo-thuidium here includes R. hvlocomioides Card. & Broth, (both R. hylocomioides var. hylocomioides and R. hvlocomioides var. qracilius) . Cardot and Brotherus (192 3) distinguished R. hylocomioides from R. pseudo-thuidium on the basis of the narrower "branch" leaves (branch order not defined) of the former species. Branch leaves, however, do not differ when the variation over the total range of the composite group is considered. Comparing the type specimens of the two species, the primary branch leaves of R. pseudo-thuidium (Fig. 46F) are somewhat more broadly ovate than those of R. hylocomioides (Fig. 46G) , but the secondary branch leaves are identical in shape (Fig. 46H vs. 461) . In addition, R. hylocomioides var. qracilius was separated on the basis of vague habit characters (smaller plants with little-branched stems and no secondary/tertiary branches) that are typical for the group as a whole. FIG. 46. Rigodium pseudo-thuidium: Gametophytic Features. A. Habit. B. Portion of stem showing position of leaves. C-E. Stem leaves showing various reduced conditions of costa. F-G. Primary branch leaves. H-I. Secondary branch leaves. J. Cross section of leaf. K. Cross section through costal area of leaf in C. L-M. Areolation of leaf. L. Marginal and intramarginal cells. M. Midlaminar cells. A-C, E, G, I, K-M from Halle & Skottsbera 842 (S, isolectotype R. hvlocomioides) ; D, J from Halle 844 (UPS, isolectotype R. hvlocomioides var. gracilius) ; F, H from Dusen 481 (S, lectotype R. pseudo-thuidium) . 229 FIG. 47. Riqodium pseudo-thuidium : Sporophytic and Related Gametophytic Features. A. Perichaetial leaf. B-C. Areolation of perichaetial leaf. B. Basal cells. C. Upper cells. D. Primary branch with perigonia. E. Perigonium. F. Perigonial leaves. G. Portion of stem with sporophyte. H. Capsule. A-C, G, H from Dusen 481 (S, lectotype R. pseudo-thuidium) ; D-F from Halle 844 (UPS, isolectotype R. hvlocomioides var. gracilius) . 231 40/um 0.3mm FIG. 48. Distribution of Ricrodium pseudo-thuidium. 233 Distribution of R. pseudo-thuidium SOUTHERN CHILE AND ARGENTINA 300km NOMINA AMBIGUA AND NUDA Eurhynchium striatellum Schimp. in Mitt., J. Linn. Soc. Bot. 12: 557. 1869, nom. inval ♦ in synon. = R. toxarion fide Mitt., J. Linn. Soc. Bot. 12: 557. 1869. Rhynchostegium striatellum Schimp. ex Par., Ind. Bryol . 1197. 1898, nom. nud. in synon. err, pro Eurhynchium striatellum. Heterocladium lechleri Schimp. in Lor., Bot. Zeit. 24: 189. 1866, nom. nud. in synon. = R. arborescens cf. Lor., Bot. Zeit. 24: 189. 1866, et p.p. R. toxarion cf. Mitt., J. Linn. Soc. Bot. 12: 557. 1869. Heterocladium prolixum Schimp. in Lor., Bot. Zeit 24: 189. 1866, nom. nud. in synon. = Heterocladium lechleri. Hypnum alajuelae C. Mull., J. Bot. 15 (n.s. 6): 230. 1877, nom. nud. Rigodium alajuelae Kindb., Enum. Bryin. Exot. 103. 1891, nom. nud. Rigodium alaguelae Par., Ind. Bryol . 1140. 1898, nom. nud. err, pro R. alajuelae Kindb. Evidently, the specimen Muller (1877) originally examined was from Costa Rica, and may, then, possibly be R. toxarion. the only species of Rigodium occurring there. 234 235 Hypnum araucarieti C. Mull. , Hedwigia 38 (Beil. ) : 58. 1899, nom. nud. The epithet was later validated in by Muller (1901) . Hypnum brachypelma C. Miill., Linnaea 43: 481. 1882, nom. inval. err, pro. H. brachypodium. Hypnum neei Mohr in C. Mvill., Svn. 2: 445. 1851, nom. nud. in synon. - R. implexum cf . Hampe fide C. Miill., Syn. 2: 445. 1851. Rigodium acuminatum Card, in Skottsb. , K. Svensk. Vet. Ak. Handl. 51 (9): 65. 1914, nom. nud. From Juan Fernandez Islands, where three species of Rigodium occur. Rigodium breviramulosum Broth, in Ren. & Card. , Bull. Soc. Roy. Bot. Belg. 32 (1): 198. 1893 [1894], nom. nud. [Anonymous s.n. , com Cardot, Brazil, H-BR] = R. toxarion. Rigodium carnosulum Dus., Rep. Princeton Univ. Exp. Patag. 8: 125. 1903, nom. nud. [Dusen 482 : BM (2 specimens), FLAS, H, JE, MICH, NY, 0, S (2 specimens), W) ] = R. brachypodium var. brachypodium . Rigodium concatenatum Lindb. in C. Mull., Linnaea 43: 481. 1882, nom. nud. The undesignated specimen Muller (1882) mentioned was from Brazil and, thus, may possibly be R. toxarion, the only species which occurs there. 236 Rigodium eleqantulum Card, in Skottsb. , Bih. K. Svensk. Vet. Ak. Handl. 51(9): 63. 1914, nom. nud. ("Halle 840: H, S, UPS; Cunningham 227: BM] = R. brachypodium var. tamarix. Rigodium elegantulum var. fernandezianum Card, in Skottsb., Bih. K. Svensk. Vet. Ak. Handl . 51(9): 63. 1914, nom. nud. in synon. = R. tamarix fide Card. & Broth. , Bih. K. Svensk. Vet. Ak. Handl. 63(10): 69. 1923. Rigodium kunerti C. Mull, in Par., Ind. Bryol . 1140. 1898, nom. nud. = R. araucarieti var. catenulatum fide C. Mull., Hedwigia 40: 82. 1901. Hypnum kunerti (C. Mull.) Broth., Bih. K. Svensk. Vet. Ak. Handl. 26 Afd. 3: 54. 1900, nom. nud. Rigodium lechleri Schimp. in C. Mull., Bot. Zeit. 16: 172. 1858, nom. nud. [Lechler 629: type R. arborescens] = R. brachypodium var. brachypodium . Rigodium longostipitatum Broth, in C. Mull., Hedwigia 40: 82. 1901, nom. nud. fLindman 176: type R. araucarieti var. catenulatum] = R. toxarion var. toxarion. Rigodium nano-fasciculare C. Mull, ex Kindb., Enum. Bryin. Exot. 103. 1891, nom. nud. orthogr. pro Rigodium nano- fasciculatum. Rigodium nano-fasciculatum C. Mull ex Dus., Rep. Princeton Univ. Exp. Patag. 8: 119. 1903, nom. nud. Rigodium nano-fasciculatum C. Mull, ex Ther. , Rev. Chilena 22: 90. Plate VI, Figs. 2a-f, 1918, nom. 237 nud. sub Art. 44.1. The epithet was later validated by Miiller (in Theriot, 1929; see Zomlefer, 1991). Rigodium penicilliferum C. Mull., Hedwigia 40: 81. 1901. TYPE: BRAZIL. SANTA CATARINA: Sao Jose, in via cava prope Praia-comprida, cum Helicodontio associatum, Jan 1887, Ule s.n. (specimen not seen). Although Ule's exsiccatae were well-distributed (Sayre, 1971) , none among the numerous of his collections on loan for this study match the locality and date cited by Miiller (1901) . Brotherus, who even distributed many of Ule's collections, stated in his keys to Riaodium (1909, 1925) that he had not seen any examples of R. penicilliferum. Subseguent to the publication of Brotherus' keys, the specimen (s) may have been lost when Miiller 's herbarium at B was mostly destroyed (Sayre, 1977) . Rigodium penicilliferum may be synonymous with R. toxarion. the only species which occurs in Brazil. Rigodium pseudo-thuidium Dus., Rep. Princeton Univ. Exp. Patag. 8: 125. 1903, nom. nud. The epithet was later validated by Dusen (1905) . Rigodium ptychomnioides Broth., Nat. 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Authors of names of bryophytes and the present location of their herbaria. Bryologist 80: 502-521. Schuster, R. M. 1983. Phytogeography of the Bryophyta. Pp. 461-626 in R. M. Schuster (ed.), New Manual of Bryology, Vol. 1. Hattori Botanical Laboratory, Nichinan, Japan. Schwagrichen, F. 1816. Joannis Hedwig. Species muscorum frondosorum. Supplementum primum. Joaniis Ambrosii Barth, Lipsiae . 1844 [1845]. Ueber einige Moose. Linnaea 18 (Ht. 5): 557-562. Sehnem, A. 1976. Musgos sul-brasileiros IV. Pesguisas, Bot. 30: 34-40. Seki, T. 1974 [1976]. A moss flora of Provinicia de Aisen, Chile. Results of the second scientific expedition to Patagonia by Hokkaido and Hiroshima Universities, 1967. 245 Sci. Hiroshima Univ., Ser. B, Div. 2 (Botany). 15: 9- 101. Sneath, P. H. A. & R. R. Sokal. 1973. Numerical taxonomy: the principles and practice of numerical classification. W. H. Freeman and Co. , San Francisco. Stark, L. R. 1987. A taxonomic monograph of Forsstroemia Lindb. (Bryopsida: Leptodontaceae) . J. Hattori Bot. Lab. 63: 133-218. Stuessy, T. F. 1990. Plant taxonomy. Columbia University Press, New York. Swofford, D. L. 1990. PAUP: Phylogenetic analysis using parsimony. Version 3.0. Illinois Natural History Survey, Champaign. Taylor, T. 1846. The distinctive characters of some new species of Musci, collected by Professor William Jameson, in the vicinity of Quito, and by Mr. James Drummond at Swan River. London J. Bot. 5: 41-67. Theriot, I. 1917. Contribution a la flore bryologigue du Chili, II. Revista Chilena Hist. Nat. 21: 6-37. . 1925. Cinquieme contribution a la flore bryologigue de Madagascar. Recueil Publ. Soc. Havraise Etudes Diverses 92: 122-151. . 1929 [1930]. Mousses critiques. Rev. Bryol . Lichenol., n.s. 2 (Fasc. 3-4): 231-233. . 1934 [1935]. Contribution a la flore bryologigue du Chili, lie article. Rev. Bryol. Lichenol., n.s. 7 (Fasc. 3-4) : 167-183. Touw, A. 1971. A taxonomic revision of the Hypnodendraceae (Musci). Blumea 19: 211-353. . 1974. Notes on taxonomic and floristic research on exotic mosses. J. Hattori Bot. Lab. 38: 123-128. U. S. Office of Geography. 1955, 1956, 1957, 1963, 1967, 1968. Official Standard Names. Gazetteer Nos. 4, (Bolivia) , 18 (Costa Rica) , 36 (Ecuador) , 71 (Brazil) , 6 (Chile, 2nd ed.), 103 (Argentina). United States Board on Geographic Names, Department of the Interior, Washington, D. C. Vitt, D. H. 1982. Bryopsida. Pp. 307-336 in S. P. Parker (ed.), Synopsis and classification of living organisms, Vol. 1. McGraw-Hill Book Co., New York. 246 . 1984. Classification of the Bryopsida. Pp. 696-759 in R. M. Schuster (ed.), New manual of bryology, Vol. 2. Hattori Botanical Laboratory, Nichinan, Japan. Walther, K. 1983. Bryophytina. Laubmoose. In J. Gerloff & J. Poelt (eds.), A. Engler's Syllabus der Pflanzenfamilien. Aufl. 13, V(2) : 1-108. Gebriider Borntraeger, Berlin. Watanabe, R. 1972. A revision of the family Thuidiaceae in Japan and adjacent areas. J. Hattori Bot. Lab. 36: 171-320. & Z. Iwatsuki. 1981. New name for Haplocladium (C. Muell.) C. Muell. (Musci) . J. Jap. Bot. 56: 259-261. Watrous, L. E. & Q. D. Wheeler. 1981. The out-group comparison method of character analysis. Syst. Zool. 30: 1-11. Wijk, R. van der, W. D. Margadant, & P. A. Florschiitz. 1967, 1969. Index Muscorum. Vol. 4 (P-S) . Vol. 5 (T- Z, addenda). Reg. Veg. 48: 1-604, 65: 1-922. Wiley, E. O. 1981. Phylogenetics. John Wiley & Sons, Inc. , New York. Wilken, D. & R. L. Hartman. 1991. A revision of the Ipomopsis spicata complex (Polemoniaceae) . Syst. Bot. 16: 143-161. Zanten, B. O. van. 1976. Preliminary report on germination experiments designed to estimate the survival chances of moss spores during aerial trans-oceanic long-range dispersal in the Southern Hemisphere, with particular reference to New Zealand. J. Hattori Bot. Lab. 41: 133-140. . 1983. Possibilities of long-range dispersal in bryophytes with special reference to the Southern Hemisphere. Sonderbd. Naturwiss. Ver. Hamburg 7: 49- 64. . 1984. Some considerations on the feasibility of long-distance transport in bryophytes. Acta Bot. Neerl. 33: 231-232. & T. Pocs. 1981. Distribution and dispersal of bryophytes. In W. Schultze-Motel (ed.), Advances in bryology, 1: 479-562. Zomlefer, W. B. 1990. Lectotypif ication of Riqodium Kunze ex Schwaegr. (Musci). Taxon: 39: 499-500. 247 1991. Identification of types and original material "for some epithets of Riaodium Kunze ex Schwagr. J. Bryol. 16: 397-402. 1992. A new species of Riqodium (Musci: Rigodiaceae) from Chile and Argentina. Syst. Bot. 17 (1) : (in press) . & W. R. Buck. 1990. A reassessment of four Riqodium types. Bryologist 93: 303-308. APPENDIX A OTUS (COLLECTIONS) USED IN THE PHENETIC ANALYSES The following lists the OTUs (collections) used in the phenetic analyses. All 12 0 OTUs were incorporated in the first study (Fig. 24) ; the starred (*) 85 OTUs were included for the second analysis of R. brachypodium var. brachypodium and R. toxarion var. toxarion complexes (Fig. 25) . The first 23 OTUs listed are type material. "Chile-J.F" refers to the Juan Fernandez Islands. Type material: *1. Ule 524 , Brazil (type R. araucarieti ; H-BR) *2. Lindman 176, Brazil (type R. araucarieti var. catenulatum; H-BR, S, UPS) *3. Lechler 629. Chile (type R. arborescens ; BM, BR, G, GB, H, L, MICH, NY, O, S, UPS, W) *4. Lorentz s.n. , Argentina (type R. argent inicum; BM, NY) *5. Bertero s.n., Chile (type R. brachypodium ; BM) *6. Tonduz [Pitter No: 1 5666, Costa Rica (type R. gracile; BR, G, NY, PC) *7. Ule 892 , Brazil (type R. hamirameum; H-BR, M) 8. Halle & Skottsberg 842 , Chile (type R. hylocomioides ; PC, S, UPS) 9. Halle 844 . Chile (type R. hylocomioides var. gracilius; PC, S, UPS) 248 249 10. Poeppig s.n., Chile (type R. implexum; BM) *11. Volkens 2349, Tanzania (type R. kilimandscharicum; H- BR, JE, M, S) *12. Germain [Muller No: 1 1166. Bolivia (type R. leptodendron; G, H-BR, JE, M, NY, S) 13. Looser 8p.p. . Chile (type R. looseri; G, PC) *14. Pus en 225. Chile (type R. nano-fasciculatum; BM, FH, FLAS, GB, H-BR, JE , M, MICH, NY, O, PC, S, W) *15. Perrier de la Bathie 168. Madagascar (type R. niveum; PC) *16. Sehnem 7367 . Brazil (type R. pallidum; PACA) *17. Schwabe 79/b2. Chile (type R. pendulum; JE, PC) *18. Ule 2135. Brazil (type R. pertenue ; FH, H-BR, M) 19. Dusen 481. Chile (type R. pseudo-thuidium ; BM, CHR, FH, FLAS, JE, M, NY, 0, S, UPS, W) 20. Skottsberq & Skottsberg 429 , Chile (type R. robustum; GB, H-BR, JE, S) *21. Jameson s.n., Ecuador (type R. solutum; E, FH) 22. Anonymous s.n., Hale Bay, Chile (type R. tamarix; BM) *23. Anonymous s.n., Hispaniola (type R. toxarion, G) Central and South American OTUs: *24. Holdridae 3023. Haiti (FH, FLAS, MICH, NY) *25. Dull 17, Mexico (ALTA, MEXU) *26. Sharp 4090. Mexico (MEXU, MICH, TENN) *27. Ventura 18869a. Mexico (ALTA, DUKE, FLAS, MEXU, NY, U) *28. Stevermark 32769. Guatemala (F, FH, MICH, NY) *29. Watson ES-0063 . El Salvador (MO) 250 *30. Crosby 3996B. Panama (DUKE, MO) *31. Hammen et al. 2676, Colombia (FLAS) *32. Troll 2017. Colombia (JE, S) *33. Fendler 135. Venezuela (BM, FH, FLAS, G, H, NY, O, S) *34. Laeaaard & Steere 27582A, Ecuador (ALTA, FLAS, NY) *35. Steere 9030. Ecuador (FLAS, NY) *36. Brvan 405. Peru (F, MO, NY) *37. Gardenas 3229. Bolivia (NY) *38. Herzocr 3817. Bolivia (FH, H, JE, L, M, NY, 0, S, W) *39. Castellanos TLIL No: 1 8806. Uruguay (FH) *40. Reitz 2610. Brazil (F, FH, FLAS, G, JE, NY, U) *41. Sehnem 315. Brazil (FLAS, PACA) *42. Sehnem 4686. Brazil (FLAS, PACA) *43. Sehnem 7087. Brazil (FLAS, PACA) *44. Ule 93. Brazil (C, DUIS, FH, FLAS, G, GOET, H, JE, L, NY, S, UPS, UWM, W) *45. Wasum 3964. Brazil (FLAS) *46. Cantino M-41. Argentina (MO) *47. Castellanos TLIL No: 1 2201. Argentina (FH) 48. Donat 2, Argentina (JE) *49. Kalela B3e. Argentina (H) 50. Kalela B4c, Argentina (H) *51. Kalela B9 3a. Argentina (H) *52. Kalela B93f . Argentina (H) *53. Kalela B130a. Argentina (H) *54. Kalela B133c. Argentina (H) 55. Kalela B136g, Argentina (H) 251 *56. Kalela B244f , Argentina (H) *57. Kalela B249i , Argentina (H) 58. Kiihnemann 5195. Argentina (ALTA, U) 59. Kuhnemann 5260, Argentina (ALTA, H, U) 60. Liunqner 1315. Argentina (JE, S) 61. Matteri & Schiavone 3525, Argentina (Herb. Matteri) 62. Matteri & Schiavone 4985. Argentina (Herb. Matteri) *63. Sleumer 1718. Argentina (B, S) 64. Barrandequy 345. Chile (MO) 65. Benove 65, Chile (H) 66. Claude-Joseph 5775. Chile (FH) *67. Crosby 11841, Chile (FLAS, MO) *68. Crosby 12022. Chile (MO) *69. Crosby 12038. Chile (MO) 70. Crosby 12295. Chile (FLAS, L, MICH, MO, NY) *71. Crosby 12365. Chile (MO) *72. Crosby 12984. Chile (FLAS, MO) *73. Crosby 12992. Chile (MO) *74. Crosby 13027. Chile (MO) 75. Dusen 75. Chile (H, S) 76. Dusen 196. Chile (CHR, H, S, UPS, W) *77. Dusen 357. Chile (BM, DUIS, FH, H, JE, MICH, NY, 0, S, UPS, W) 78. Dusen 397. Chile (CHR, DUKE, FH, FLAS, GB, NY, S) 79. Dusen 409. Chile (BM, CHR, DUIS, FH, H, JE, M, MICH, NY, 0, S, UPS, W) *80. Dusen 482. Chile (BM, FLAS, H, JE, MICH, NY, O, S, W) 252 81. Pus en 625. Chile (BM, S, W) *82. Dusen s.n., lac Llanquihue, Chile (S) *83. Elliott 139. Chile (H, L, 0) 84. Godlev 105. Chile (BM, FLAS, H) 85. Guisinde 4492. Chile (B, BM, BR, C, F, G, GB, H, KRAM, L, M, O, S, W) *86. Hahn s.n.. Chile (B, BM, C, CANM, DUKE, F, FLAS, MICH, MO, OXF, NY, S) 87. Halle 840. Chile (H, S, UPS) *88. Hollermaver 259. Chile (B, S, W) *89. Hollermaver 281a. Chile (S, W) *90. Hosseus 147. Chile (JE) *91. Kunkel 2029. Chile (B, H) *92. Landrum 167. Chile (MO) *93. Landrum 240. Chile (MO) *94. Landrum 588. Chile (MO) 95. Lechler 620a. Chile (BM, BR, G, H, L, NY, O, OXF, S, UPS, W) *96. Mahu 12530. Chile (MO) *97. Neaer 10, Chile (S) 98. Oberdorfer 178a. Chile (JE) *99. Oberdorfer 279b. Chile (JE) *100. Reiche 6, Chile (H) 101. Roivainen 1595. Chile (H) 102. Roivainen 1597. Chile (FH, H) *103. Schwabe 197. Chile (JE) *104. Schwabe s.n., 1940, Chile (JE) 253 *105. Seki 64. Chile (H) 106. Thaxter fCardot No; 1 83. Chile (FH, FLAS, MICH, NY) 107. Tsudaii & Yoshida 844. Chile (H) 108. Vergara 2917. Chile (G) *109. Hatcher & Enael 631. Chile-J.F. (DUKE, G, MICH, NY) 110. Skottsbera & Skottsbera M197 . Chile-J.F. (FH, GB, H, S, UPS) *111. Skottsbera & Skottsbera 409. Chile-J.F. (GB, H, NY, S, UPS) *112. Skottsbera & Skottsbera 418. Chile-J.F. (GB, H, S) *113. Skottsbera & Skottsbera 439. Chile-J.F. (BM, GB, H, NY, S) African OTUs: *114. Crosby & Crosby 13266A. Tanzania (MO) *115. Pocs 6782/B. Tanzania (G, L, MO, VBI) *116. Rwarden 11792. Malawi (O, VBI) *117. Mviller 2635. Zimbabwe (L, MO) *118. Schelpe 5552. Mozambique (BM, C, S) *119. Crosby & Crosby 7637. South Africa (DUKE, L, MO) *120. Vorster 1761b. South Africa (L) APPENDIX B DETERMINATION OF MINIMUM NUMBER OF MEASUREMENTS PER CHARACTER Below is justification for the choice of five measurements (for each character per OTU) as sufficient to obtain a mean which is an adequate estimation of the actual mean for that character for an OTU (Steven Linda, pers. comm. ) . These equations demonstrate a relationship between sample size (n) and the 95 per cent confidence interval for the actual mean (u) of a given OTU. For y, the sample mean of a measurement for a particular character for a given OTU, the variance of y or V(yj is: V(y> = £i_2 . N_^J! , n N where a 2 is the variability (variance) within a specimen and N is the actual total number of characters on an OTU (e.g., all the stem leaves in a collection). When N is sufficiently large, as in this study with moss exsiccatae, N-n = 1, N resulting in: v(y) - ^2 n The 95 per cent confidence interval for u (the actual mean of a given OTU) is: 254 M - Y ± t (n-l) , 0.025/^. 255 e n Note that the variability within a specimen ( oe 2 ) is inversely proportional to the sample size (n) . The t statistic (n-l degrees of freedom, at alpha level, 0.025) is also dependent on the value of n and also decreases as n increases. Simplifying the eguation further: M = y ± t (n-l) . 0.025 /ot A plot of t (n-l), 0.025//" vs. n (Fig. 49A) shows an apparent leveling of the curve around n values of four or five measurements. An additional plot (Fig. 49B) of the difference between between two consecutive numbers t(n_2), 0.025//n-l - t/n_]\ f 0.025//°" vs* n snows that the effect adding one additional measurement again levels off around four measurements. FIG. 49. Plots of the Relationship Between Number of Measurements (n) per OTU and the t Statistic. A. Graph showing relationship between n and the t statistic as expressed in the equation (presented in the text) for the 95 per cent confidence interval for the actual mean (u) . B. Graph showing the difference between two consecutive numbers . 257 to CM O d c > B o d i IO CM o d cm* I c > n n BIOGRAPHICAL SKETCH Wendy B. Zomlefer was born in Fitchburg, Massachusetts, on September 22, 1954. She attended public schools in Leominster, Massachusetts, and graduated from Leominster High School in 1972. In 1976, she received the Bachelor of Science degree in botany from the University of Vermont. From 1976 to 1978, she was employed as a botanical illustrator and herbarium assistant at the Marie Selby Botanical Gardens in Sarasota, Florida. For the next two years, Wendy studied under Walter S. Judd at the University of Florida in Gainesville, receiving the degree of Master of Science in botany in December 1980. For the past ten years, she has held the position of Medical Illustrator for the Natural Sciences Department at the Florida Museum of Natural History, University of Florida. Her graduate studies towards the Doctor of Philosophy degree in botany under the direction of Dana Griffin, III, were begun in September 1986. 258 I certify that I have read this study and that in my opinion it conforms to the acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degreef of Doctor of- Philosophy. klW H 4fc& . Dkna G. Griffin J fj.ll,\ Chair Professor of Botany I certify that I have read this study and that in my opinion it conforms to the acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy,. Walter S. Judd Associate Professor of Botany I certify that I have read this study and that in my opinion it conforms to the acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. .ogy James W. KimbroUgh Professor of Plant Pathol< I certify that I have read this study and that in my opinion it conforms to the acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Bruce /Ji. MacFadden ^75, Professor of Zoology I certify that I have read this study and that in my opinion it conforms to the acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor c-f— Ehilosophy. "Jonathan Reiskind Associate Professor of Zoology This dissertation was submitted to the Graduate Faculty of the College of Agriculture and to the Graduate School and was accepted as partial fulfillment of the requirements for the degree of Doctor of Philosophy. ~ JeW. j£_cJW Dean, College/of Agriculture May 1991 Dean, Graduate School UNIVERSITY OF FLORIDA II!IIII«IC"73 3 1262 08554 0473