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1.
Conantiopteris schuchmanii gen. et sp. nov. The specimen, 23.2 cm long and 11.7 cm wide, shows helically arranged persistent frond bases embedded in
adventitious roots, and is clothed by multicellular trichomes. A parenchymatous pith with mucilaginous cells and sclerotic
nests is surrounded by an amphiphloic distyostele, parenchymatous inner cortex, and outer sclerenchymatous cortex. Sclerenchyma
also surrounds the cauline vasculature and leaf traces. Medullary and cortical bundles are absent. Phloem contains both axially
elongated and tangential sieve elements. Frond bases are oval in outline with three vascular bundles, including an undulating
abaxial arc and an adaxial pair. Protoxylem of the stipe is endarch and is associated with cavity parenchyma. These characters
are indicative of tree fern affinities. A cladistic analysis using trunk characters of both living and fossil tree ferns was
conducted to help establish relationships of the new species and other fossil ferns, and to test hypotheses of general tree
fern relationships. Additional analyses of living taxa only were also performed. Results from the analysis using both living
and fossil taxa compare favorably with those that included only living species when either morphological characters or molecular
sequences of the chloroplast gene rbcL are utilized. Although there are variations in the topologies of the various trees, results indicate that the new genus is
nested among a paraphyletic assemblage of dicksoniaceous, lophosoriaceous, and metaxyaceous species that subtend a monophyletic
Cyatheaceae s.s.
Received 26 April 1999/ Accepted in revised form 15 July 1999 相似文献
2.
N. S. Nagalingum 《Plant Systematics and Evolution》2007,264(1-2):41-55
Three new taxa from Albian, Early Cretaceous assemblages in Gondwana (Australia and Antarctica) and two previously described
fossils from the Late Cretaceous and Eocene of North America are attributable to the heterosporous semi-aquatic fern family
Marsileaceae. They are assigned to Marsileaceaephyllum, a morphotaxon erected here for sterile remains (whole plants, and isolated leaves and leaflets) of Marsileaceae. The Gondwanan
taxa, Marsileaceaephyllum lobatum and Marsileaceaephyllum spp. B-C, have either a cruciform leaflet arrangement or dichotomous and anastomosing venation characteristic of modern Marsileaceae.
Two previously established taxa, Marsilea johnhallii and Marsilea sp., which represent sterile Marsileaceae, are also transferred to the new genus (now Marsileaceaephyllum johnhallii and Marsileaceaephyllum sp. A, respectively). Examination of all fossil venation patterns reveals four new venation types not present in extant taxa,
suggesting that most fossil Marsileaceae (leaves) are distinct from extant genera, and are likely members of extinct lineages.
This is further supported by the absence of modern megaspore types in the Early Cretaceous. 相似文献
3.
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. 相似文献
4.
We describe 16 new species of Thelypteris (Thelypteridaceae) from Bolivia: T. aymarae, T. chaparensis, T. fasciola, T. fayorum, T. inaequilateralis, T. lumbricoides, T. madidiensis, T. minima, T. nephelium,
T. parva, T. pelludia, T. pilonensis, T. rosulata, T. sapechoana, T. stephanii, and T. yungensis. 相似文献
5.
John T. Mickel 《Brittonia》2001,53(4):487-489
Elaphoglossum trichomidiatum is described from northeastern Mexico. The new species is a member of theE. petiolatum comples, which is widespread in tropical America, Africa, Southeast Asia, and the Pacific Islands. It is unique in the complex
and in sectionLepidoglossa in bearing trichomidia on the abaxial blade surface. 相似文献
6.
Toshiyuki Sato 《Journal of plant research》1990,103(2):165-176
A quantitative comparison was conducted on the foliage development during sporophyte development of three allopatric ferns in cool temperate and subalpine regions of Hokkaido and Tirol, European Alps. The foliage development ofDryopteris crassirhizoma, D. coreano-montana andD. filix-mas was quantitatively described by the leaf development (NV, number of veins); NV correlates the leaf-shape complexity from a circle (DI, L/2(3.14×S)1/2). Nearly similar patterns were detected on frequency distribution of fertile leaves, fertility increase and number of leaves in threeDryopteris ferns which exhibit funnel-shaped foliage arrangements in mature sporophyte. No difference was found in number of leaves, maximum NV, fertility rate and leaf-shape parameters among three ferns. A positive difference was found only on changes in order of pinnae with maximum number of costa branches (NVP) and the DI of outline of pinnae betweenD. crassirhizoma andD. filix-mas. These allopatricDryopteris ferns seem to have a similar foliage structure, in spite of some sympatricDryopteris ferns capable of producing putative hybrids (D. austriaca andD. amurensis; D. tokyoensis andD. monticola) having different foliage structures in Hokkaido. Contribution No. 3346 from the Institute of Low Temperature Science, Hokkaido University. 相似文献
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9.
Three new species of ferns are described from Mexico:Athyrium tripinnatum, Cystopteris millefolia, andPolypodium praetermissum. 相似文献
10.
Alexandre Salino 《Brittonia》2002,54(4):331-339
Three new species ofThelypteris are described and illustrated:T. littoralis andT. paranaensis, endemic to the rainforest of the southern Brazilian Atlantic coast, andT. multigemmifera, endemic to inland gallery forests of the São Paulo state. In addition, four new combinations are made:T. cutiataensis (Brade) Salino,T. iguapensis (C. Chr.) Salino. A new name is proposed forDryopteris lugubris var.quadrangularis:T. montana Salino. The species treated here belong toThelypteris subg.Goniopteris due to the indument of furcate and stellate trichomes. 相似文献
11.
采用光学显微镜对旱生金毛裸蕨(Gymnopteris vestita)配子体发育的全过程进行了观察。结果显示,(1)旱生金毛裸蕨孢子三裂缝,成熟时黄褐色,接种后10~15d萌发,萌发类型为书带蕨型。原叶体母细胞首先形成单列的丝状体,其后配子体发育明显区别于非旱生的蕨类,金毛裸蕨配子体发育最明显的特征是形成大量的分枝,通常单列的丝状体基部细胞可通过细胞纵分裂形成丝状分枝,这些分枝又可进一步产生新的分枝,分枝的末端可形成片状体,这些片状体又可产生分枝丝状体或片状体,最终整个配子体可发育为群丛。有时,单列的丝状体也可直接发育为片状体,然而这些片状体并不发育为原叶体而是产生大量的丝状分枝。当群丛形成时,在丝状体或片状体表面可产生数量较多的精子器,但在人工培养条件下并没有发现颈卵器。如果培养条件适宜,配子体可进行营养繁殖,持续较长时间,老的片状体上可产生新的丝状体。金毛裸蕨位于群丛外的大型心形原叶体可进行无配子生殖产生孢子体。金毛裸蕨的配子体发育特征,包括多分枝、发达的营养繁殖及无配子生殖现象的发生,表明了金毛裸蕨配子体群丛的形成是对于旱生环境的一种适应性。 相似文献
12.
A new hybrid,Lomariopsis ×farrarii, is illustrated and described from the La Selva Biological Station, Costa Rica. It is intermediate between its parents,L. japurensis andL. vestita in length and color of the rhizome scales, shape and number of the pinnae, and size and division of the juvenile leaves in a heteroblastic series. 相似文献
13.
The antifungal efficacy of Ficus sycomorus and Pergularia tomentosa plant extracts on Bufo regularis experimentally infected with Aspergillus niger was studied. After an oral administration of the pathogen for 15 days, the blood, kidney and liver were examined. Treatment with A. niger produced a reduction in red blood count cells and hemoglobin content. Also, both livers and kidneys revealed marked destruction and degenerative changes. These changes included congestion of blood vessels, leukocytic infiltration, and cytoplasmic vacuolization of the hepatocytes. As well as complete destruction of the cellular boundaries of the tubular epithelia, inflammatory leukocytes between the intertubular spaces, destruction and necrosis in renal tubule cells and the swollen glomeruli with wide glomerular spaces were seen. Pretreatment with F. sycomorus and P. tomentosa plant extracts 1 h prior the administration of A. niger for two weeks improved blood parameters and protected against hepatic and renal damage as observed from histological examination and reduced spore numbers in culture media on these organs. 相似文献
14.
M. J. Asíns R. Herrero L. Navarro 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(6):892-898
Ten enzymatic systems of Citrus species and cultivars have been evaluated for identification purposes and for genetic variability studies. The following factors that could affect their expression were studied: season of sampling, location, rootstock, position of the branch, infection, and age of the tree. Differences involving the presence-absence of the Cu/Zn SOD within the same tree were found. This difference is mainly related to the position of the leaf relative to the sunlight. No change was observed at any of the ten enzymatic systems assayed regarding the location, the rootstock, the growing condition, the season, or the infection with most virus and virus-like pathogens. Viroids induced noticeable changes on 6PG and PRXa zymograms in C. medica. A new peroxidase (not present in healthy plants) was detected that could be related to appearance of symptoms. This may induce errors when trees without sanitary control are characterized by this enzymatic system. On the other hand, it provides a new possibility for studying the plant response to the presence of viroids. An effect of age, from 3 months up to 12 years, was observed on citrange Troyer and mandarin Cleopatra PRX, MDH and 6PG patterns. An important change occurs around the first year, most likely related to the end of the seedling stage. This is followed by a long transition phase, the end of which (around 9 years later) coincides with a change in the PRX pattern. These age-related changes seem to involve post-translational modifications of pre-existing isozymes. 相似文献
15.
Two different morphogenetic pathways, adventitious bud and corm-like structure (CLS), were observed on organogenic calli derived
from the petioles of Amorphophallus albus in vitro. The organogenic calli was established via culture of petiole segments on Murashige and Skoog (MS) medium supplemented
with 1.0 mg l−1 α-naphthaleneacetic acid (NAA) and 1.0 mg l−1 6-benzyladenine (BA) and subculture of the petiole-derived calli on MS medium with 0.5 mg l−1 NAA and 0.5 mg l−1 BA. These organogenic calli were used to induce morphogenesis via culture on MS medium with various concentrations of NAA
and BA. BA alone favoured adventitious bud differentiation (57.0 ± 8.3% at maximum) from the organogenic calli but inhibited
CLS formation. In the presence of NAA and BA, both adventitious bud and CLS were observed in a same culture system. The maximum
CLS formation (71.2 ± 9.3%) were found on MS medium with 0.5 mg l−1 NAA and 2.0 mg l−1 BA, associated with 26.7 ± 8.6% adventitious bud differentiation. A small part of the adventitious buds developed into normal
shoots which needed rooting culture phase to form complete plants. About 80% survival rate was obtained with these plants
after transplantation to soil. More than 90% of the CLSs produced complete plants with shoots and root systems, regardless
of the rooting media tested. Transplantation of the CLS-derived plants to soil gave 100% survival rate. Histological observations
revealed both the two morphogenetic events originated from the meristematic cells located in superficial layers of callus
tissue. 相似文献
16.
Lignite fossil flowers (including pollen) and isolated stamens of probable hamamelidalean (possible hamamelidaceous) affinities from the upper Cretaceous (Late Santonian or Early Campanian) of Sweden are described. The flowers are 6–7-merous with probably a double perianth, one whorl of stamens and (2-?)3 carpels. The stamens are disporangiate; each theca opens by a valve towards the centre of the flower. Pollen is tricolpate, tectate-columellate and reticulate; the endexine is lamellated in the apertural region. The gynoecium has free styles and a syncarpous ovary. In the one flower that was serially sectioned the ovary is either non-functional or development of the few (2?) ovules is retarded. 相似文献
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18.
Botryosphaeria spp. are common endophytes of woody plants, and they also include some serious pathogens of Eucalyptus and Acacia species. Numerous anamorphs have been associated with Botryosphaeria, of which the species Fusicoccum are amongst the most common. Here, we characterize two new Fusicoccum species, isolated from Eucalyptus and Acacia trees in Venezuela, based on morphological features in culture and comparisons of DNA sequence data. The two taxa named Fusicoccum andinum and F. stromaticum spp. nov, reside in two well-supported clades (BS values = 100 %) based on a combined data set of the ITS of the rDNA operon and translation elongation factor 1-α (EF1- α) gene sequences. The conidia of F. andinum are unusually large amongst Botryosphaeria anamorphs, and peripherally resemble those of B. mamane and B. melanops. F. stromaticum is characterized by large conidiomata in cultures, growth at 35 °C and slightly thickened conidial walls, which is different to most other Fusicoccum spp. No teleomorphs were observed for these fungi, but DNA sequence data show that they are anamorphs of Botryosphaeria. 相似文献
19.
Phylogenetic utility and comparative morphology of the composite scale brushes in male phycitine moths (Lepidoptera, Pyralidae) 总被引:2,自引:0,他引:2
Male pyralid moths in the subfamily of Phycitinae are known to possess composite scale brush structures associated with the 8th abdominal sternite, but the histology and the structural morphology of these organs have not been adequately explored. As such, the phylogenetic utility of these structures is unknown. We examine the pre-genitalic abdominal histology of male Dioryctria reniculelloides (Pyralidae: Phycitinae) associated with the composite scale brushes, as well as structural morphology within the genus Dioryctria and two closely related genera. The composite scale brushes are composed of fused scales. The musculature associated with the base of sternum 8 shows considerable modification compared to previously described Lepidoptera. Complex glandular tissue was also found associated with the scale brush structures, suggesting secretory function. Phylogenetic utility of ultrastructure and gross morphology was examined for major Dioryctria species groups. Many characters were homoplasious, but several supported the monophyly of the genus, as well as some internal relationships. In conclusion, the combination of ultrastructural, gross morphological and histological characters can be a rich source of information for elucidating a range of evolutionary relationships within the subfamily. 相似文献
20.
Leticia Pacheco 《Brittonia》2004,56(2):121-123
A new species ofDiplazium,D. lellingeri from Ecuador, is described and illustrated.
Resumen Se describe e ilustra una nueva especie deDiplazium de Ecuador,D. lellingeri.相似文献