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1.
Ceratozamia norstogii sp. nov. from Chiapas, Mexico is described. This species is distinct from all others in the genus in that it has a straight rachis with very narrow leaflets (3–10 mm wide) which are strongly curved and almost round in cross section when dried. It is known only from Chiapas, Mexico and in cultivation.  相似文献   

2.
A taxonomic re-evaluation of the Ceratobasidium-Rhizoctonia group suggests that Ceratobasidium contains only the type species C. calosporum, which deviates in micromorphological and ultrastructural characters from all other species so far included in that genus. Rhizoctonia species are compared with the type species of Ceratobasidium, Cejpomyces, Oncobasidium, Tofispora, Waitea, and Ypsilonidium. The micromorphology, ultrastructure, cellular interaction with the host, and molecular phylogeny of a Rhizoctonia species parasitic on needles and young shoots of Picea abies have been studied. The parasite has been known for a long time, but misinterpreted, and not named so far. Rhizoctonia butinii is described and compared with related species of the genus.  相似文献   

3.
J. M. Campbell 《ZooKeys》2014,(415):269-293
The species of the genus Charisius Champion, from Mexico and Central America are reviewed. The flightless genus Narses Champion, with one included species, N. subalatus Champion, is placed in synonymy with the genus Charisius. Four new species are described and illustrated, C. granulatus and C. punctatus (from Guatemala) and C. apterus and C. howdenorum (from Mexico). Charisius subalatus (Champion) is redescribed and illustrated. The species C. interstitialis Champion is placed in synonymy with C. zunilensis Champion. The genus is redescribed to include the four new species and N. subalatus. New distributional records are presented for all other species of the genus and a revised key is presented for identification of all the species of the genus.  相似文献   

4.
A new white truffle species, Tuber panzhihuanense from China   总被引:1,自引:0,他引:1  
A new white Tuber species, T. panzhihuanense, is described based on collections from Sichuan and Yunnan, China. This is one of 10 new white truffle species, which were discovered in 2010 and 2011. Morphological and molecular analysis shows that T. panzhihuanense is clearly different from any other taxon in the genus of Tuber. It grows in mycorrhizal association with trees of Pinus yunnanensis in limestone soils. It has a pleasant aroma and is good edible. This is the first white truffle species discovered in China that has commercial potential.  相似文献   

5.
Accurate delimitation of species is a critical first step in protecting biodiversity. Detection of distinct species is especially important for groups of organisms that inhabit sensitive environments subject to recent degradation, such as creeks, springs, and rivers in arid or semi-desert regions. The genus Dionda currently includes six recognized and described species of minnows that live in clear springs and spring-fed creeks of Texas, New Mexico (USA), and northern Mexico, but the boundaries, delimitation, and characterization of species in this genus have not been examined rigorously. The habitats of some of the species in this genus are rapidly deteriorating, and many local populations of Dionda have been extirpated. Considering the increasing concerns over degradation of their habitat, and pending a more detailed morphological revision of the genus, we undertook a molecular survey based on four DNA regions to examine variation over the range of the genus, test species boundaries, and infer phylogenetic relationships within Dionda. Based on analyses of two mitochondrial (cytb and D-loop) and two nuclear (Rag1 and S7) DNA regions from specimens collected throughout the range of Dionda, we identified 12 distinct species in the genus. Formerly synonymized names are available for two of these species, and four other species remain undescribed. We also redefine the known range of six species. The limited distribution of several of the species, coupled with widespread habitat degradation, suggests that many of the species in this genus should be targets for conservation and recovery efforts.  相似文献   

6.
Two new species of Leptolobium from Brazil are described and illustrated. Leptolobium araguaiense, restricted to northern Brazil, is similar to L. panamense, but differs in raceme length, ovary pubescence, flower and bract length, hilum shape, habit, geographical distribution, and preferential habitat. Leptolobium multijugum, from midwestern Brazil, is perhaps most closely related to L. glaziovianum, but it has more numerous leaflets and smaller bracts and bracteoles than any other species in the genus.  相似文献   

7.
Macaranga (Euphorbiaceae) is a genus of tropical trees. Five aspects of species evolution in Malaya are discussed. (1) Seventy per cent (20) of the species in Malaya have come to be common as small trees in secondary forest. Their original habitat was small forest clearings mainly along rivers, where they grow as big trees in small populations, fruiting all the year round. Their biology has enabled them to become the most successful genus in the extensive secondary forests that have resulted from forest clearing over the last 90 years. In so spreading they have not hybridized or developed regional differences within the country. (2) There are however marked differences from populations in northern Borneo, 800 km east over the shallow South China Sea; this is thought to reflect morphological divergence since the lands were last separated in the Pleistocene. (3) M. andamanica has a disjunct distribution coupled with polymorphism. (4) M. laciniata which replaces M. heynei in north and east Malaya has trivial morphological differences, thought to be genetically simple. (5) M. quadricornis , member of a close-knit species group round M. triloba , grows in lowland swampy forest in south Malaya to 2o20'N and in the mountains of central and north Malaya from 3o20'N. It is a very conspicuous and common species yet no intermediates have been found between these two groups. The simplest explanation of the disjunction in habitat and distribution seems to be that it has evolved twice from out of its complex.  相似文献   

8.
Rita Singh  P. Radha 《Brittonia》2006,58(2):119-123
A new cycad species,Cycas annaikalensis, has been discovered from the Malabar Coast of the southern Western Ghats of India. Although geographically distributed in a small population within the range ofC. circinalis, it can be distinguished from the other described IndianCycas species by its distinct habitat, habit, morphology of vegetative and reproductive parts, and anatomy of leaflets.  相似文献   

9.
Liu Z J  Liu K W  Chen L J  Lei S P  Li L Q  Shi X C  Huang L Q 《农业工程》2006,26(9):2791-2799
Paphiopedilum armeniacum is an endangered orchid species, endemic to China. During the period of April 2000 to October 2005, 66 observation sites were selected in Luoshapo of Nushan Mountains in Yunnan, China, to carry out the conservation ecological research on P. armeniacum. A total of 443 genets (1302 ramets in total) of P. armeniacum were sampled, their biological characteristics such as reproductive pattern, phenology, and life cycle were observed, and the ecological habits of the species such as the habitat and the structure of communities were studied. Experiments on ex-situ conservation were conducted, and the cloned ramets were replanted to their original habitat after ex-situ reproduction in Shenzhen, Guangdong, China. The relationships between P. armeniacum and climate, vegetation, other environmental factors in the original habitat, and the biological characteristics of asexual offsprings of P. armeniacum, which were replanted to the original habitat after ex-situ cultivation and reproduction, were investigated. The studies show that P. armeniacum in Luoshapo grows very well in secondary shrub boskets or in tussocks on limestone hills. It has both sexual and asexual reproduction. Asexual reproduction serves to complete the sexual reproduction and to extend the lifetime of genets, while it does not reduce sexual reproduction. There are two modes of asexual reproduction-by tillering or by producing rhizomes. The litter of shrub boskets or tussocks provides P. armeniacum with humus, and the rhizome reproduction of P. armeniacum is an adaptation to the litter-covered condition, i.e. to escape from the unfavorable environment. Blooming rate of ramets is 7.39% 1.02%, and fruit set rate from the blooming ramets is 32.23% 12.08%. P. armeniacum is able to invade the moderately destroyed forests and those in early restoring but is unable to grow in large dense forests. P. armeniacum also grows very well in artificial spare woods in Shenzhen and can reproduce many cloned ramets, which can normally bloom and yield fruits after being replanted to the original habitat. The results of this study show that P. armeniacum can be conserved by ex-situ conservation and by replanting the ex-situ reproduced ramets to original habitat. On the basis of the analysis of endangered mechanisms of P. armeniacum, it can be concluded that P. armeniacum has strong capability of both asexual and sexual reproductions, and an emergency mechanism consisted of massive production of rhizomes to cope with damage. Because highly effective pollinating insects that facilitate pollination in P. armeniacum are present in the habitat, flowering ramets produce fruits with large quantity of seeds, many of which in turn grow into new genets that can reproduce many cloned ramets. P. armeniacum makes very effective use of its environment and has distinct characteristics of enduring harsh environmental conditions; therefore, rather than its own inherent biological defects, the main threats facing this species are the destruction of its survival space and the wipe-out collecting of the plants as a result of trading. Based on the analysis mentioned above, certain appropriate strategies have been proposed for the conservation of P. armeniacum.  相似文献   

10.
11.
The flavonoid chemistry of eight species of Chrysosplenium has been established. The species studied were C. americanum, C. echinus, C. flagelliferum, C. glechomaefolium, C. iowense, C. rosendahlii, C. wrightii and C. valdivicum. The major compounds present were O-methylated flavones having an extra hydroxyl group at positions 6 and/or 2′ except for C. valdivicum which has isorhamnetin as its major flavonoid and only a trace of a compound bearing an extra hydroxyl group. Distribution of the O-methylated compounds in the genus correlates well with Franchet's sectional view of the genus wherein he recognized alternate-leaved vs opposite-leaved groups. The flavonoids of C. valdivicum represent a link between the more advanced members of the genus and other genera of the Saxifragaceae.  相似文献   

12.
Understanding the processes that underpin adaptive evolutionary shifts within major taxonomic groups has long been a research directive among many evolutionary biologists. Such phenomena are best studied in large monophyletic groups that occupy a broad range of habitats where repeated exposure to novel ecological opportunities has happened independently over time in different lineages. The gekkonid genus Cyrtodactylus is just such a lineage with approximately 300 species that range from South Asia to Melanesia and occupy a vast array of habitats. Ancestral state reconstructions using a stochastic character mapping analysis of nine different habitat preferences were employed across a phylogeny composed of 76% of the known species of Cyrtodactylus. This was done in order to ascertain which habitat preference is the ancestral condition and from that condition, the transition frequency to more derived habitat preferences. The results indicate that a general habitat preference is the ancestral condition for Cyrtodactylus and the frequency of transitioning from a general habitat preference to anything more specialized occurs approximately four times more often than the reverse. Species showing extreme morphological and/or ecological specializations generally do not give rise to species bearing other habitat preferences. The evolution of different habitat preferences is generally restricted to clades that tend to occur in specific geographic regions. The largest radiations in the genus occur in rocky habitats (granite and karst), indicating that the transition from a general habitat preference to a granite or karst‐dwelling life style may be ecologically uncomplicated. Two large, unrelated clades of karst‐associated species are centered in northern Indochina and the largest clade of granite‐associated species occurs on the Thai‐Malay Peninsula. Smaller, independent radiations of clades bearing other habitat preferences occur throughout the tree and across the broad distribution of the genus. With the exception of a general habitat preference, the data show that karst‐associated species far out‐number all others (29.6% vs. 0.4%–10.2%, respectively) and the common reference to karstic regions as “imperiled arcs of biodiversity” is not only misleading but potentially dangerous. Karstic regions are not simply refugia harboring the remnants of local biodiversity but are foci of speciation that continue to generate the most speciose, independent, radiations across the genus. Unfortunately, karstic landscapes are some of the most imperiled and least protected habitats on the planet and these data continue to underscore the urgent need for their conservation.  相似文献   

13.
The adults’ mobility and oviposition preferences of Zerynthia cassandra have been studied for the first time, with the aim of integrating auto-ecological information into recommendations for the habitat’s management of this species. Results of our mark-release-recapture study have highlighted that Z. cassandra is a strictly sedentary species, since detected movements only occurred over very short distances (≤200 m) and mainly within the species’ reproductive habitat (i.e. around Aristolochia rotunda stands), with males moving further than females. Our study shows that the main oviposition habitat of Z. cassandra is found where A. rotunda plants are growing in large stands; sites where plants growing in half to full sun and mostly oriented to the south are preferred. The distance of deposited eggs from the plants’ roots was narrowly correlated with the plants’ length. Eggs were deposited singly, mainly on the underside of leaflets. Management strategies necessary for improving the most important habitat features for the conservation of this species are suggested.  相似文献   

14.
王文采 《广西植物》2016,36(Z1):95-96
该文描述了自广西发现的毛茛科铁线莲一新种,靖西铁线莲,此新种与宝岛铁线莲在亲缘关系上接近,与后者的区别在于本种的茎疏被短柔毛,小叶卵形或狭卵形,不分裂,聚伞花序有1~3花,萼片较大长1.7~2 cm,宽0.5~0.7 cm。  相似文献   

15.
16.
王文采 《广西植物》2016,36(Z1):233-235
描写了自黑龙江省发现的紫堇科紫堇属一新种,鹤岗延胡索。此种与新疆元胡相似,但本种叶的小叶多在顶端具1~5牙齿,花序苞片有3~5小裂片,上花瓣及其辦片和距均较小,蜜腺呈狭卵球形,弯曲,顶端尖锐而与新疆元胡相区别。  相似文献   

17.
Both male and female of a new species of Eriopeltasttes Burmeister & Schaum, 1840, E. (E.) ornatus Ricchiardi, sp. n., are described from the mistbelt grassland of KwaZulu-Natal. Sexual dimorphism is extreme in this genus, with females being brachypterous, fossorial and entirely black to dark brown in general body colour. This is only the fifth out of 12 known species in this genus for which the female is known. The species appears to be restricted to areas within or in the immediate vicinities of two marginal nature reserves, Karkloof and Blinkwater, in a grassland habitat that is regarded as one of the most threatened in the Province of KwaZulu-Natal. Despite its acknowledged importance as centre of endemism the area is currently in a precarious state of large-scale degradation.  相似文献   

18.
The genus Impatiens (Balsaminaceae) includes three widespread species in the Czech Republic, central Europe: the native I. noli-tangere, and two invasive species, I. parviflora and I. glandulifera, differing in the dynamics of invasion. They all occur in similar habitats and share basic life-history characteristics, which make them a suitable model for studying species traits associated with invasiveness. In this study we investigated differences in habitat requirements of these Impatiens species, their coexistence and short-term population dynamics in the field. We established 84 1 × 1 m permanent plots in five localities where all three species co-occurred. In each plot vascular plant species were determined, their cover estimated and all individuals of Impatiens species counted. Site characteristics including tree canopy cover, soil moisture, nitrogen and carbon content, and slope were measured directly. Nutrients, light, humidity and soil reaction were estimated using Ellenberg indicator values. The presence of I. noli-tangere was strongly correlated with high soil moisture, that of I. parviflora with high tree canopy cover and low soil moisture. Impatiens glandulifera exhibited a unimodal response to tree canopy cover, avoiding both very shaded and fully open sites. The current-year abundances of all species were negatively related to those of congeneric species. These results suggest that the coexistence of Impatiens species in the same habitat is due to microsite differentiation. Further spread of I. glandulifera to new habitats, and reduction of the native I. noli-tangere niche, can be expected in areas where the latter species co-occurs with competitively strong invasive congeners.  相似文献   

19.
Euryte koreana sp. nov. is described from the shallow littoral on the East Coast of South Korea, and represents the first record of the subfamily Euryteinae Monchenko, 1974 in the Pacific Ocean north of the tropics. It belongs to a group of species that have the caudal rami length/width ratio of around four, but differs from all congeners by a number of morphological features. Detailed drawings and extensive scanning electron micrographs of many characters of ornamentation provided for this species should serve as a benchmark for distinguishing closely related species in this subfamily with conservative macro-morphology. A morphologically distinct population from anchialine caves in Mallorca, identified previously as Euryte longicauda Philippi, 1843, is described as another new species: Euryte jaumei sp. nov. To test the phylogenetic relationships of its members and previous hypotheses about generic placement of two species associated with scleractinian corals, several cladistic analyses are performed on all 16 currently recognized species of Euryteinae and two outgroups, Neocyclops australiensis Karanovic, 2008 and Troglocyclops janstocki Rocha and Iliffe, 1994, using 25 morphological characters. All resulting trees suggest a close relationship between the two commensal species and them as a sister clade to all other Euryteinae. They are transferred into a newly erected genus Coraleuryte gen. nov., as C. bellatula (Humes, 1991) comb. nov. and C. verecunda (Humes, 1992) comb. nov., and a revised diagnoses is provided for the genus Euryte Philippi, 1843. Obtained cladograms also show that Ancheuryte Herbst, 1989 is nested deeply within the Euryte clade, so the genus is synonymized and its only species is transferred, as E. notabilis (Herbst, 1989) comb. nov. A key to species of Euryteinae is also provided.  相似文献   

20.
Traditionally, zooplankton studies have been carried out on larger species and later developmental stages, at least in the case of copepods. This fact is due to the difficulty of distinguishing between all the morphologically very similar species and genus, especially at immature stages. Nowadays, however molecular techniques allow us to discriminate these species easily. We have developed a RFLP (Restriction Fragment Length Polymorphism) technique to distinguish between the species of the genus Clausocalanus which are present at our study zone, the Central Cantabrian Sea. This genus belongs to the “small” fraction of mesozooplankton (500-200 μm), and it has been scarcely studied even though it is an important component of the mesozooplankton. This technique allows identification of individuals and from small body parts.  相似文献   

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