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1.
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   

2.
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   

3.
Stegnogramma pozoi (Lagasca) K. Iwats. subsp.mollissima (Fischer ex Kunze) K. Iwats. is one of the most common ferns in Japan with a very broad geographical distribution and habitat ranges. We examined the intrasubspecific variation of therbcL gene, and found three types in the subspecies (Atami-1, Atami-2, and Tateyama types). The Atami-1 and 2 types shared three apomorphic nucleotides and their geographical distribution is intermingled. Thus, we considered them to have intraspecific variation. In contrast, the Tateyama type had 4–5 different nucleotides than the Atami types, and showed a more northern distribution. Leaf morphology of the Tateyama type is distinct from that of the Atami types, though the leaf shape in Tateyama type varies considerably and in some cases overlaps with other types. Ferns have fewer morphological features that are systematically significant than flowering plants because they lack complex reproductive organ. It is reasonable to expect that species recognition of ferns based only on leaf morphology can be fine tuned by molecular features. Variation in therbcL sequences might be useful as an indication of significant biological units.  相似文献   

4.
5.
李中阳  和兆荣 《广西植物》2010,30(4):443-445
根据标本研究和野外观察,将疏羽毛蕨、拟渐尖毛蕨、慈利毛蕨和光叶毛蕨处理为渐尖毛蕨的异名。  相似文献   

6.
将乐清毛蕨( Cyclosorus luoqingensis )处理为德化毛蕨(C.dehuaensis)的异名,南岭毛蕨(C.narlingensis)和少羽毛蕨(C.paucipinnus)处理为[梣]叶毛蕨(C.fraxinifolius)的异名,倒披针毛蕨(C.oblanceolatus)处理为南平毛蕨(C.nanpingensis)的异名,雁荡毛蕨(C.yandongensis)和寻乌毛蕨(C.xunwuensis)处理为华南毛蕨(C.parasiticus)的异名,并作了相应的讨论。  相似文献   

7.
Three new neotropical species of subulate-scaledElaphoglossum are described and illustrated:E. minutissimum, E. rosettum, E. semisubulatum. The first occurs in Costa Rica, the second and third in Bolivia.  相似文献   

8.
Rumex sect.Axillares first described by the author in 1937 is known to be represented in N. America by 20 endemic species. From S. America only five species, all endemic, were previously known; this number is raised in the present revision to 15. Outside America there exist small groups of endemic species in S. Africa and in the islands of Hawaii as well as in Australia and scattered single species in C. Africa, on the remote Atlantic islands of Tristan de Cunha and Gough Island, and in eastern Asia.—In Europe the section is completely absent, except for three American species which occur as rare aliens. TheAxillares are not only morphologically well-characterized by their growth—no leaf rosettes, flowering period practically unlimited by formation of later flowering axillary shoots, flowers often monoecious—but also by their genetic structure expressed by a different behaviour in hybridization. Hybrids are frequent between species of sect.Rumex (syn.Simplices) and are easy to recognize by their sterility which results in a certain peculiarity in habit. In contrast, no spontaneous hybrids are known with certainty among species of sect.Axillares. Most artificial hybrids are fairly fertile. So far only three hybrids between species of the two sections have been known. Three more have been found by the author in Chile, all being highly sterile and showing the growth characteristics resulting from sterility as occur in hybrids between species of sect.Rumex.
Resumen Rumex secciónAxillares fue descrito por primera vez por el autor en 1937. Se conoce en América del Norte con 20 especies endémicas. De América del Sur se conocían sólo 5 especies, todas ellas endemicas; este número asciende a 15 en la presente revision. Fuera de las Américas se encuentran pequeños grupos de especies endémicas en Sudáfrica, en las Islas de Hawaii y en Australia; especies aisladas se encuentran en Africa Central, en las lejanas Islas Atlánticas de Tristan de Cunha y Gough Island y en Asia Oriental. La sección no tiene representantes en Europa, con excepción de tres especies americanas introducidas, poco frecuentes. La secciónAxillares se caracteriza bien, tanto morfológicamente por su forma de creciemiento—sin rosetas foliares, período floral prácticamente ilimitado por la formación de inflorescencias axilares parciales, flores a menudo monoicas—como por su estructura genética que se manifiesta en un comportamiento diferente de hibridación. Híbridos son frecuentes en las especies de la secciónRumex (syn.Simplices) y reconocibles por su esterilidad que se expresa en cierta particularidad del habito. Al contrario, no hay seguridad de híbridos espontáneos en la secciónAxillares. La mayor parte de los híbridos artificiales son totalmente fértiles. Hasta ahora se conocían solo tres híbridos entre las especies de ambas secciones. Otros tres han sido encontrados por el autor en Chile. Todos completamente estériles y con las características de hábito típicas resultantes la esterilidad, como ocurre en los híbridos de la secciónRumex.
  相似文献   

9.
Solanum homalospermum (Solanum subgen.Leptostemonum) is described and illustrated from central Argentina.Solanum homalospermum is characterized by having heteromorphic gynoecia, strongly flattened seeds, unequal anthers, and gemmiferous roots.  相似文献   

10.
报道了广西毛蕨属Cyclosorus植物6个新记录种:三都毛蕨C.sanduensis,学煜毛蕨C.houi,缩羽毛蕨C.abbreviatus,毛囊毛蕨C.hirtisorus,巨型毛蕨C.subelatus,秦氏毛蕨C.chingii,并提供了广西产该属植物的分种检索表。  相似文献   

11.
Pollen viability has been investigated in 20 blackberry species using 3 methods, (1) cotton blue, (2) TTC, and (3) germination in a sucrose solution. Significant differences were found between species. Correlations between high pollen viability and high seed set were also obtained.  相似文献   

12.
InRubus L. a connection seems to exist between the degree of meiotic disturbances on the one hand, and the production of unreduced embryo sacs, pollen fertility and relative seed set on the other hand. Severe meiotic disturbances commonly encountered in apomictic taxa decrease pollen fertility and thereby seed set since pollen is necessary for endosperm development. By contrast interspecific hybrids between apomictic taxa appear to be sexual and exhibit high pollen fertilities, probably due to an improved meiosis. Thus, apomixis leads to a decreased fertility inRubus, not the opposite, as often discussed.  相似文献   

13.
14.
H. Nybom 《Oecologia》1987,72(4):562-568
Summary Pseudogamous blackberry species are polyploid and usually exhibit meiotic irregularities causing severe reduction in pollen viability. When species means were compared, relative seed set was strongly correlated with the number of good pollen grains produced per flower divided by the number of ovules (good-pollen/ovule ratio).Partial correlation analysis for percentage viable pollen and relative seed set, controlling for good-pollen/ovule ratio, revealed an almost significant relationship, presumably because meiotic irregularities have a similar effect on both pollen viability and the viability of meiotically derived embryo sacs. Seed germination, on the other hand, showed no relationship with relative seed set or with pollen viability.The automatic selfing capacity exhibited by most of these blackberry species does not appear to be related to either pollen production or relative seed set.  相似文献   

15.
The pollen morphology of 29 species ofOdontites and related genera was examined by light and scanning electron microscopy. Three major pollen types differing fundamentally in exine sculpturing were found. In the parasitic tribePedicularieae retipilate sculpturing is the most widespread type representing a plesiomorphic character state from which the two other types are derived. Of these, reticulate sculpturing is confined toOdontites, whereas a complex retirugulate pattern was found only in the monotypic Near East genusBornmuellerantha. Within the retipilate and the reticulate major types eight minor types were distinguished based on the differential correlation of exine surface morphology, size, shape and amb form. The pollen data are generally well correlated with macromorphological features and furnish important taxonomic characters at the genus—as well as at the specieslevel.  相似文献   

16.
Nutlet sculpturing of 22 taxa ofScutellaria sect.Resinosa, representing 18 of its 19 species, and the monotypic genusSalazaria was studied by scanning electron microscopy (SEM). The nutlets of sect.Resinosa, while remarkably variable among themselves, differed from hypothetically closely related sections in lacking circumferential banding and sessile glands. Species could be grouped by surface sculpturing into seemingly meaningful phenetic clusters.Scutellaria potosina var.platyphylla was sufficiently distinct micromorphically so as to be elevated to specific status asScutellaria platyphylla comb. and stat. nov. The significance of nutlet microcharacters within sect.Resinosa is discussed, especially as compared to closely related sections. The genusSalazaria had nutlet sculpturing quite different from all taxa belonging to sect.Resinosa.  相似文献   

17.
A review of current knowledge of chromosome numbers and modes of reproduction in the genusRubus L. is presented. Chromosome numbers from some species of subg.Malachobatus Focke together with results of crossing experiments are reported for the first time.  相似文献   

18.
Polygonum sect.Tovara comprises three morphologically very similar species;P. virginianum,P. filiforme, andP. neofiliforme. Sequences of internal transcribed spacers (ITSs) of nuclear ribosomal DNA of these were determined to examine phylogenetic relationships and the levels of differentiation among them. The size of ITS 1 was 241 bp inP. filiforme andP. neofiliforme, and 242 bp inP. virginianum. The size of ITS 2 was 243 bp, and that of the 5.8S rRNA coding region was 163 bp. The ITS sequences clearly separate North AmericanP. virginianum from the eastern Asian species. Nucleotide divergence between them ranges from 3.3% to 3.8% for ITS 1 and from 9.3% to 10.7% for ITS 2. The molecular data also revealed that two eastern Asian species are closely related but should be treated as distinct species.  相似文献   

19.
At an early stage of growth gametophytes support the sporophytes of ferns. Young sporophytes become independent of gametophytes when the first leaves develop. Although large fern gametophytes produce multiple archegonia simultaneously, only one sporophyte is typically established on one gametophyte. The number of sporophytes is believed to be controlled in two possible directions, from gametophyte to sporophyte or from preceding sporophyte to another sporophyte. To investigate the effects of gametophytes on their sporophytes, we studied the relationship between organic matter production by gametophytes and the growth of young sporophytes of Thelypteris palustris. We cut gametophytes in half (CGs) to reduce the gametophytes’ production of matter. There was no significant difference between the growth of sporophytes on intact gametophytes (IGs) and that on CGs. According to our estimates, based on the rate of organic matter production, the large gametophyte was able to produce two or more sporophytes. The resources required for CGs to make similar-sized sporophytes was twice that for IGs. In polyembryony each of the multiple sporophytes was similar in size to the single sporophytes. Resource limitation does not seem to explain why fern gametophytes establish single sporophytes.  相似文献   

20.
The fine structure of the type species of the genusCyanothece Komárek 1976,C. aeruginosa, is described and compared with the main cytological characteristics of morphologically related members of the generaCyanobium, Cyanobacterium andSynechococcus. Several morphological features, such as cell walls with thick outer layers containing a special type of vesicles, position of thylakoids, keritomy (net-like appearance of protoplast caused by arrangement of thylakoids, net-like nucleoids and/or by tendency to form intrathylakoidal spaces) and a special structure of mucilaginous envelopes were found to be characteristic of this genus, supporting its separate position among coccal cyanoprokaryotes (cyanobacteria, cyanophytes). The taxonomic significance of ultrastructural features in all mentioned genera is discussed.  相似文献   

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