Three new species of ferns (Woodsiaceae and Polypodiaceae) from Mexico

Three new species of ferns are described from Mexico:Athyrium tripinnatum, Cystopteris millefolia, andPolypodium praetermissum.     

A new species of Diplazium (Woodsiaceae) from Ecuador

A new species ofDiplazium,D. lellingeri from Ecuador, is described and illustrated.

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Resumen  Se describe e ilustra una nueva especie deDiplazium de Ecuador,D. lellingeri.

     

Monograph of the neotropical species of Callipteris with anastomosing veins (Woodsiaceae)

Callipteris is a pantropical fern genus defined by two synapomorphies of its rhizome scales: 1) dark-castaneous to black borders, and 2) bifid marginal teeth. This monograph treats 15 neotropical species ofCallipteris that are further defined by the synapomorphy of anastomosing veins (free-veined species of the genus occur in the Neotropics and elsewhere). Three species are newly described here; the remaining 12 were previously classified inDiplazium. All the species ofCallipteris grow on wet forest floors at 100–2300 m. In the Neotropics the genus occurs from Guatemala to Bolivia, northern Brazil, and the Lesser Antilles. It has two centers of species richness. The first is the Chocó region on the western side of the Andes in Colombia and northwestern Ecuador. This region contains eight species, five of which are endemic. The second center is the mountains of Costa Rica and Panama, where six species occur, three of which are endemic. Only one species, an endemic, occurs in the Lesser Antilles in Martinique, St. Vincent, and Grenada. Four species occur only on the eastern side of the Andes, and these apparently represent at least two separate dispersal events from the western side of the Andes.     

岩蕨科、球盖蕨科的系统位置:叶绿体DNAtrnL-F区序列证据

岩蕨科(Woodsiaceae)和球盖蕨科(Peranemaceae)历来被多数学者认为是亲缘关系密切的两个科,它们的系统位置一直存在争议,两科曾被放入三叉蕨科(Aspidiaceae)、碗蕨科(Dennstaedtiaceae)、鳞毛蕨亚科(Dryopteridoidaae)及鳞毛蕨科(Dryopteriaceae)蹄盖蕨亚科(Athyrioideae)中.根据岩蕨科1种、球盖蕨科3种、蹄盖蕨科8种、鳞毛蕨科2种及1种外类群假大羽铁角蕨(Asplenium pseudolaserpitiifolium)的cpDNA基因trnL-F区序列建立的系统树,结果显示,岩蕨科和球盖蕨科的亲缘关系较远,岩蕨科与蹄盖蕨科有密切的亲缘关系,球盖蕨科与鳞毛蕨科亲缘关系较近,岩蕨科和球盖蕨科是处于不同进化线上的植物.秦仁昌(1978)和Pichi-Sermolii(1977)的系统将二者分别作为独立的科是合适的.     

Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification

The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date. In this study, we carry out comprehensive phylogenetic analyses of Woodsiaceae using molecular evidence from four chloroplast DNA markers (atpA, matK, rbcL and trnL–F) and covering over half the currently recognized species. Our results show three main clades in Woodsiaceae corresponding to Physematium (clade I), Cheilanthopsis–Protowoodsia (clade II) and Woodsia s.s. (clade III). In the interest of preserving monophyly and taxonomic stability, a broadly defined Woodsia including the other segregates is proposed, which is characterized by the distinctive indument and inferior indusia. Therefore, we present a new subgeneric classification of the redefined Woodsia based on phylogenetic and ancestral state reconstructions to better reflect the morphological variation, geographic distribution pattern, and evolutionary history of the genus. Our analyses of the cytological character evolution support multiple aneuploidy events that have resulted in the reduction of chromosome base number from 41 to 33, 37, 38, 39 and 40 during the evolutionary history of the cliff ferns.     

Prothallia in nine species of Callipteris and its comparison with other genera of the Woodsiaceae family

The development of the prothallia in nine species of Callipteris Bory (Woodsiaceae), four species of Diplazium, the genus from which Callipteris has been segregated, and one species of Dryoathyrium are studied in this paper. The data obtained are compared with the development of the prothallia of several other genera of Woodsiaceae. The main difference between Callipteris and the other genera of Woodsiaceae was that the antheridia dehiscence of Callipteris, occurs by an opercular cell and whereas some of Diplazium and other Woodsiaceae antheridia dehiscence occurs by a lateral or apical pore. The presence of antheridiogens is suspected on the basis of small ameristic male gametophytes in the cultures. Spore germination in Callipteris is Vittaria-type, prothallial development corresponds to Adiantum-type.     

Patterns of variation of a common fern (Athyrium filix-femina; Woodsiaceae): population structure along and between altitudinal gradients

Genetic variability of Athyrium filix-femina populations was evaluated with regard to phenotypic, allozyme, and RAPD variation in 20 Swiss populations along five altitudinal gradients at four different elevations in the northern Swiss Alps. Additionally, allozyme and phenotypic variations in one Italian and two Spanish populations were compared with the variation in the Swiss populations. We hypothesized that there will be statistically significant genetic differences among populations of different altitudes and sites. The results showed no substantial correlation between genetic variation and phenotypic variation among Swiss populations. These results imply that outbreeding and effective gene exchange (long-distance spore dispersal) are the keys to population structure in this fern species, and as a consequence, phenotypic plasticity is assumed to be favored. This contrasts with results found in similar studies of herbaceous flowering plants where genetic adaptation to gradients like altitude is common. However, when data from the more distant Italian and Spanish populations of A. filix-femina were included, significant variation was detected.     

Cytological and Reproductive Studies on Japanese Diplazium (Woodsiaceae; Pteridophyta): Apomictic Reproduction in Diplazium with Evergreen Bi- to Tripinnate Leaves

Diplazium , including polymorphic terrestrial species with evergreen bi- to tripinnate leaves. Diplazium hachijoense, D. virescens var. virescens, var. conterminum, var. okinawaense, and two other unnamed varieties, D. kawakamii var. kawakamii, D. dilatatum var. heterolepia, D. taiwanense, D. × kawabatae (=D. dilatatum × taiwanense), D. × takii (=D. hachijoense × virescens var. virescens), and D.× nakamurae (= D. hachijoense × virescens var. conterminum) are apomictic triploids (2n=n=123). Diplazium amamianum and D. esculentum are sexual diploids (2n=82, n=41) and D. subtripinnatum is a sexual tetraploid (2n= 164, n=82). Diplazium dilatatum var. dilatatum includes both sexual diploid and apomictic triploid populations. Cultivated gametophytes of six triploid taxa produced sporophytes apogamously, confirming their apomictic reproduction. All three putative hybrids, D. × kawabatae, D. × takii, and D. × nakamurae, are triploid, apomictic, and fertile taxa, therefore they are not the result of hybridization between known pairs of Japanese Diplazium plants. Received 16 March 1999/ Accepted in revised form 30 September 1999     

Taxonomic Studies of the Diplazium mettenianum Complex (Woodsiaceae; Pteridophyta) in Japan: Morphology, Cytology and Taxonomy of Plants with Normal-Shaped Spores

Diplazium mettenianum complex, including two polymorphic species D. mettenianum and D. griffithii, with normal-shaped spores collected from 62 sites. An analysis of 20 qualitative morphological characters showed that the complex can be divided into five forms. A statistical analysis of 16 quantitative morphological characters supported the distinctness of five forms which are regarded as independent species: D. mettenianum, D. fauriei, D. deciduum nom. nov. (=D. mettenianum var. tenuifolium), D. griffithii, and D. hayatamae sp. nov. A cytological study on 150 plants showed that D. deciduum and plants in a single population of D. fauriei are sexual hexaploids (2n=6x=246=123ll), and all others are sexual tetraploids (2n=4x=164=82ll). Received 18 May 1998/ Accepted in revised form 3 December 1998     

<Emphasis Type="Italic">Diplazium mickelii</Emphasis> — a new species of Woodsiaceae from Brazil

A new species, Diplazium mickelii Mynssen & Sylvestre, only known from the mountain forests of Espírito Santo, Brazil, is described and illustrated.     

Apomixis in the interspecific triploid hybrid fern <Emphasis Type="Italic">Cornopteris christenseniana</Emphasis> (Woodsiaceae)

Cornopteris christenseniana is a "sterile" interspecific triploid hybrid of diploid C. crenulatoserrulata and tetraploid C. decurrenti-alata. Morphological and cytological studies show that, of 41 young plants of Cornopteris that have been propagated naturally in the Fern Garden of the Botanical Gardens, University of Tokyo, 30 plants are the sterile C. christenseniana, 10 are fertile C. decurrenti-alata and 1, fertile C. crenulatoserrulata. This proportion supports the view that the young plants of C. christenseniana are derived from spores of reproductively mature plants of the species cultivated. Cytogenetic observations and culture experiments show that C. christenseniana produces normal spores in various proportions in some sporogenetic pathways that are aberrant from the ordinary process in sexual and apomictic ferns. Under culture conditions, normal spores germinate in rough proportion to the frequency of normal spores, and sporophytes are apogamously produced in rough proportion to the frequency of spore germination. As a whole, the rates of spore germination and apogamous sporophyte development vary according to the specific plant. Taken together, these observations suggest that C. christenseniana is an incipient apomict. Electronic Publication     

Cytological and Reproductive Studies of Japanese Diplazium (Woodsiaceae; Pteridophyta). III. The Cytological Complexity of Species Groups with Simply Pinnate to Bipinnatifid Leaves

Diplazium with simply pinnate or bipinnatifid leaves. Diplazium wichurae var. wichurae, D. wichurae var. amabile, D. okudairae, and D. pin-faense are sexual diploids (2n=82; n=41II); D.× kidoi and D. × okudairaeoides are sterile diploids (2n= 82; meiosis irregular); D. donianum var. donianum is an apomictic triploid (2n=123; n=123II); D. donianum var. aphanoneuron is a sterile triploid (2n=123; meiosis irregular); D. crassiusculum, D. cavalerianum, D. incomptum, D. longicarpum, and D. pullingeri are sexual tetraploids (2n= 164; n=82II); and D. lobatum is an apomictic tetraploid (2n=164; n=164II). This is the first report of the chromosome numbers of D. lobatum, D. crassiusculum, D. incomptum, D. longicarpum, D. pullingeri, and D. × okudairaeoides, as well as the mitotic chromosome numbers of D. wichurae var. amabile, D. okudairae, D. pinfaense, and D. ×kidoi. The mitotic chromosome number, meiotic behavior, sterility, and allozyme analysis confirm that D. × kidoi and D. × okudairaeoides are hybrids between D. pin-faense and D. wichurae var. wichurae and D. okudairae and D. wichurae var. wichurae, respectively. Diplazium with simply pinnate to bipinnatifid leaves displayed an extraordinary cytological and reproductive complexity: a polyploidal series with diploids to hexaploids, sexual and apomictic reproduction, and natural hybridization. Received 14 August 2001/ Accepted in revised form 1 October 2001     

Cytological and Reproductive Studies of Japanese Diplazium (Woodsiaceae; Pteridophyta). II. Polyploidy and Hybridity in the Species Group with Summer-Green Bi- to Tripinnate Leaves

Diplazium with summer-green bi- to tripinnate leaves. Diplazium mesosorum and D. sibiricum var. sibiricum are sexual diploids (2n=82; n=41ll); D. chinense and D. squamigerum are sexual tetraploids (2n=164; n=82ll); and D. sibiricum var. glabrum is a sterile triploid (2n=123; meiosis irregular). Diplazium nipponicum includes both sterile triploid and sexual tetraploid populations. The triploid is larger in relation to several morphological characteristics and occurs in more southern regions than the tetraploid. Allozyme analysis suggests that the triploid is a hybrid of recurrent origin between the tetraploid and an unknown diploid. Diplazium × bittyuense is a sterile tetraploid, and the mitotic chromosome number, meiotic chromosome behavior, and allozyme analysis confirm the working hypothesis that it is a hybrid between D. nipponicum and D. chinense. Apomicts are not found within Diplazium with summer-green bi- to tripinnate leaves, and the taxonomic complexity can be attributed to polyploidy and natural hybridization. Received 3 March 2000/ Accepted in revised form 19 April 2000