首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The geographic distribution of three closely related Hyalomma species, namely Hyalomma (Euhyalomma) truncatum Koch, 1844, Hyalomma (Euhyalomma) albiparmatum Schulze, 1919 and Hyalomma (Euhyalomma) nitidum Schulze, 1919 is confined to Africa. A detailed comparison of all stages of development of the three taxa reveals that they possess many more shared than distinguishing characters. In fact differentiation between these species is based on single or dual qualitative characters on their adults. These are a conspicuous, ivory-coloured parma on H. (E.) albiparmatum males, and the absence or reduction in clarity of ivory-coloured bands on the leg segments of H. (E.) nitidum adults, as well as the shape of the external cuticular preatrial fold of the genital operculum of females of the latter species. The adults of all three species and the larva of H. (E.) truncatum are redescribed. The nymph of H. truncatum and the larva and nymph of H. (E.) albiparmatum and H. (E.) nitidum are described for the first time. Data on their geographic distributions and hosts are provided.  相似文献   

2.
Codonopsis pilosula subsp. tangshen is illustrated: its relationships, history and pollination are discussed. Instructions for its successful cultivation are given, and references are given to its use in Traditional Chinese medicine.  相似文献   

3.
《Journal of bryology》2013,35(4):268-276
Abstract

Two little known species of Cheilolejeunea, C. microscypha (Hook.f. & Taylor) M.Wigginton, comb. nov. (a reinstated St Helena liverwort), and C. rotalis (Hook.f. & Taylor) M.Wigginton comb. nov., endemic to St Helena, South Atlantic Ocean, are described and illustrated, and oil bodies of C. ascensionis (Hook.f. & Taylor) Grolle are newly described and illustrated.  相似文献   

4.
Male and female imagines, and pupal exuviae of Cricotopus (C.) nevadensis sp. n. are described. A discussion on the systematic position, a differential diagnosis and notes on the ecology of this new species are given.  相似文献   

5.
《Journal of bryology》2013,35(2):133-142
Abstract

Macrodictyum is a small acrocarpous moss genus of three species (M. latifolium (E.B.Bartram) M.J.Price, M. proliferum (Mitt.) E.H.Hegew., M. wrightii (Sull.) E.H.Hegew.). It grows in tufts and mats on trees or rocks at 450–1500 m in the Neotropics. The genus has a restricted distribution within the Neotropics and is currently known from only a few localities in Cuba, the Dominican Republic, and southeastern Brazil. Macrodictyum is characterized by four main features: 1) appressed, non-crispate, ovate–oblong, lingulate to ligulate or linear leaves; 2) large, rhomboidal, thin-walled cells in the upper leaf; 3) large, irregular, multicellular apical teeth; and 4) guide cells that are ventral at and above mid-leaf. These features are atypical of the Dicranaceae. However, Macrodictyum shares pseudautoicous sexuality, sheathing perichaetial leaves, and peristome structure with the large pantropical Dicranaceous genus Holomitrium Brid. In these two genera the peristome consists of 16 single, triangular, entire or weakly divided, fenestrate, striate teeth that are papillose throughout on both the inner and outer surfaces. Macrodictyum is retained in the Dicranoideae (Dicranaceae), close to Holomitrium, based on its pseudautoicous sexuality, sheathing perichaetial leaves, and peristome structure.  相似文献   

6.
Abstract

The various stages of female gametophyte development and embryogenesis in S. spiralis and S. aestivalis are described. In both species the reproductive cycle is sexual. Some peculiarities are present: the female gametophyte is usually 6-7-8-nucleate; after double fertilization a single endospermatic cell is formed; the proembryo appears differentiated and is made up of different cells in the chalazal and micropylar ends; a single basal cell in the proembryo acts as suspensor.  相似文献   

7.
Nutlets of Hemigenia R.Br. and Microcorys R.Br. were examined using SEM. Significant variation, mainly useful at the infrageneric level, was found in nutlet shape, nature of the attachment scar, nature of surface sculpturing, exocarp cell shape and sculpturing, and nature of the indumentum. Typical nutlets are ovoidal, strongly reticulate or rugose. The exocarp cells are isodiametric and convex to papillate. Also common are cylindrical nutlets, often with longitudinal ridging and papillate exocarp cells. Surface pitting and concave exocarp cells are rare. A cladistic analysis of nutlet characters suggests both Hemigenia and Microcorys are polyphyletic, and Microcorys paraphyletic with respect to Westringia Sm. Notwithstanding that, the infrageneric classification of Hemigenia was largely supported, while in Microcorys, there was support for sect. Hemigenioides, but sects Anisandra and Microcorys were not resolved as distinct.  相似文献   

8.
The morphology, ecology, cytology and systematics of Acrochaetium botryocarpum (Harv.) J. Ag. have been studied. This species occurs throughout the year in southern Australia and grows on a variety of hosts. The variable appearance of the prostrate system results from the effect of the substratum upon its morphology. Plants reach a height of 6 mm; cells of the erect filaments contain a single chromoplast with a variable number of pyrenoids. Tetrasporangial plants occur mainly in winter and sexual plants occur mainly in spring and early summer; the two generations are isomorphic. Stages of fertilisation have been observed and photographed. Acrochaetium polyrhizum (Harv.) J. Ag. is referred to the synonomy of A. botryocarpum, and A. codicolum Brg., A. grande (Levr.) De Toni fil. and A. rhizoideum (Drew) Sm. are regarded as probable synonyms. This study of A. botryocarpum indicates that host specificity, substrate relations, form of spermatangia and immediate post-fertilisation activity may not be as reliable as formerly thought for making taxonomic distinctions within the Acrochaetium-Rhodochorton complex.  相似文献   

9.
The organ bearing the sporangia of Biscalitheca kansana is a laminate rachis with subopposite fertile appendages, a structure previously unknown for Biscalitheca. The sporangia differ from those of the petrified Biscalitheca musata only by lacking nests of sclerotic cells. They contain spores which are called Convolutispora when found dispersed. Speculations are made that Monoscalitheca fasciculata will ultimately be regarded as a synonym of Biscalitheca musala and that some fossils called Aphlebia and Brittsia problematica may be the sterile foliage of zygopterids.  相似文献   

10.
A new species is added to the monotypic African genus Djinga. Djinga cheekii Ghogue, Huber & Rutish. (Podostemaceae) is described as a new species from Cameroon (Littoral Province) and its morphological affinities and conservation status are assessed. The main distinguishing characters are: stamens 2 (not 1 as in D. felicis), flower buds inside spathella strongly inclined (not only slightly inclined as in D. felicis), and stems lacking or only up to 6 mm long (not up to > 6 cm as in D. felicis). A molecular analysis revealed that D. cheekii is sister to D. felicis, and both together are sister to Ledermanniella linearifolia and L. pusilla which show completely inverted flower buds inside the spathella, as typical for the large and still artificial genus Ledermanniella.  相似文献   

11.
Summary Carnoya kermarreci n.sp. (Rhigonematidae; Nematoda) is described from Anadenobolus politus (Porat) (Rhinocricidae; Diplopoda) from Guadeloupe. The new species most closely resembles C. martiniquensis Adamson, 1984 from A. politus in Martinique and C. venezuelensis Adamson, 1984 from Rhinocricus flavocinctus from Venezuela in that the lips in the male are broad and the arrangement of caudal papillae is almost identical in the three species. Males of C. kermarreci are easily distinguished by the absence of spines, by the form of the cuticular projections at the base of the buccal cavity and by the fact that the most anterior pair of caudal papillae are located very close together. Females are distinguished by the presence of three pairs of somatic papillae near the level of the vulva. The nematode fauna of A. politus includes species from two distinct orders and presumably reflects the fact that diplopods are among the most ancient hosts of nematodes.  相似文献   

12.
Rosularia globulariifolia (Fenzl) A. Berger and R. pallidiflora (Holmboe) Meikle were originally described as species in Umbilicus DC. in 1842 and 1914, respectively. In the present study, morphological and palynological features were examined in detail to determine the status of these taxa. The general characteristics, seed structure and micromorphology, pollen measurements and pollen characteristics were established. Morphologically, the two taxa cannot easily be distinguished. Pollen grains of both species are tricolporate, subspheroidal and eutectate, ornamentation is psilate and exine structures are similar. Based on morphological and palynological similarities, and the fact that both taxa are found in the same habitats, we propose that R. pallidiflora should be reduced to the rank of variety as Rosularia globulariifolia (Fenzl) A. Berger var. pallidiflora (Meikle) Minareci & K. Yildiz comb. et stat. nov.  相似文献   

13.
A new species of mycelium-forming yeast,Endomycopsis platypodis Baker et van Rij is described. It occurs as an auxiliary ambrosia fungus of the wood-boring ambrosia beetlePlatypus cylindrus Fab. (Col. Platypodidae) and is the first fungus to become established in new tunnels where it forms a sparse irregular lining. Later a palisade-formingSporothrix becomes the dominant fungus in a mixed ambrosial flora. E. platypodis, which is apparently homothallic, assimilates nitrate and weakly ferments glucose. The asci typically contain 4 hat-shaped ascospores. Assimilation reactions and morphology are described and the affinities of the new species are discussed.  相似文献   

14.
Two new taxa of Minuartia L. (Caryophyllaceae) from Turkey, Minuartia aksoyi M. Koç & Hamzao?lu sp. nov. and Minuartia buschiana Schischk. subsp. artvinica M. Koç & Hamzao?lu subsp. nov. are described and illustrated. Their taxonomic positions are discussed and they are compared with allied taxa. The distributions of the new and closely related taxa are given. Seed structures were examined by SEM.  相似文献   

15.
Lathyrus sect. Lathyrostylis includes 20 Eurasian species that are more or less xerophytic. They are mainly distributed in South Europe and Southwest Asia, especially in Turkey. The majority of the species inhabits dry meadows, scrubs, Pinus forests, macchies, rocky slopes and screes. The following diagnostic characters are valuable: All species are perennial. The pinnate leaves consist of (1–)2–3(–8) pairs of parallelveined, amphistomatic leaflets and the rachis ending in a simple tip. The style is linear to broadly spathulate but not twisted. Within the section neither subsections nor series can be distinguished. The study is mainly based on herbarium specimens. Only few species had been cultivated. A key to species and subspecies and new maps, mainly based on revised herbarium specimens, are given. Species and infraspecific taxa are described, and their variability, relationships, phytogeography and ecology are discussed. At last some supplements and corrections to the revision of Lathyrus sect. Orobus (Bässler 1973) are added.  相似文献   

16.
17.
P. F. Galichet 《BioControl》1961,6(3):203-205
Summary Larvae ofDiparopsis watersi roths, are parasitized in the Tchad Republic by an unspecifiedMermitidae and byCarcelia evolans wied. (Tachinidae). TheMermis is only active during the rainy season, when 40% ofD. watersi larvae are commonly parasitized. More than one individual are able to develop inside the same host, a maximum of 44 being quoted; yet, solitaryMermis are of a greater length, the biggest recorded being 325 mm long. C. evolans is found all along the active life ofD. watersi. There is usually only one dipterous larva in each host: Out of more than a hundred cases, only twice two and thrice threeTachinidae were encountered in the same host. Evolution of theseC. evolans larvae is uncertain, only one of them developping into an adult. Association ofMermis andC. evolans, though exceptional, was also observed. This was described eight times through a three years survey; again, only one of the dipterous larvae developped into adult. The most extraordinary case reported concerns threeC. evolans encountered together with two Nematoda in the same host. An explanation to the unusual multiparasitism observed may be sought in an exceptional abundance ofC. evolans, combined with a relative scarcity of the host during the month of september 1956.   相似文献   

18.
19.
A taxonomic revision ofVerbesina sect.Ochractinia is presented. 40 species plus 7 additional infraspecific taxa are recognized. A table of the distribution of the species, key to the species and synonymy are included. Relationships to other sections ofVerbesina and species relationships within sect.Ochractinia are discussed.  相似文献   

20.
刺孢小克银汉霉[Cunninghamella echinulata(Thaxt.) Thaxt. ex Blakeslce]是小克银汉霉属的模式种,多年来因不同作者是否将贝尼尔小克银汉霉(C. bainieri Naum.)包含在内而对此种持广义(sensu lato)或狭义(scnsu stricto)的不同理解。我们在国内分离到51株刺孢小克银汉霉(广义)菌种,经与获自css的7株菌(包括刺孢小克银汉霉的模式菌种在内)和IMI的1株菌(原定名称均为刺孢小克银汉霉)一起研究后,根据它们的无性型形态特征有明显不同但在配合试验中又可互相配合形成可育的接合孢子的结果,认为将它们处理为同一个种的两个不同变种较为合理.其中,13株中国的菌和3株CBS及IMI的菌被鉴定为刺孢小克银汉霉原变种(C. echinulata var. echinulata);其余的38株中国的菌和5株CBS的菌被鉴定为轮生刺孢小克银汉霉变种(新组合)[C. echinulata var. verticillata (F. S. Paine.) comb. nov.j.以‘轮生(verticillata)’作为新组合变种的加词是根据与贝尼尔小克银汉霉同物异名的‘轮生布拉小克银汉霉(C. blakesleeana var. verticillata (F. S. Paine) Baijal & B. S. Mchrotra)’而来的.在前人的工作中,对刺孢小克银汉霉持狭义理解的作者往往根据孢子枝的分枝方式、巨型暗色孢子的有无、以及40℃能否生长来区分这两个分类群.对刺孢小克银汉霉持广义理解的作者则认为这些特性毫无意义.我们同意后面两个特性意义不大,因为二者的许多菌系都能形成巨型暗色袍子并在40℃生长,但认为孢子枝分枝方式确实是区别这两个分类群的重要依据.此外,根据产孢构造的种类、孢子枝主枝的直径、孢子枝第一次分枝的数目、分枝长度、孢子枝主枝的顶生泡囊形状以及其直径等性状综合考虑,这两个分类群是不难明确区分的,对12株刺孢小克银汉霉原变种和13株轮生刺孢小克银汉霉相互之间所进行的配合试验结果表明,在具一定性亲和力的(+)、(一)菌系同时存在时,两个变种内和变种之间均可形成可育的接合孢子。对上述三种配合的各六对菌所形成的有性型形态的研究结果则表明,除轮生刺孢小克银汉霉变种内形成的接合孢子的壁往往较厚外,各种配合形成的有性型形态基本上是一致的.我们研究组的其他成员最近曾对小克银汉霉的22株菌进行了rDNA的ITS区的PCR产物长度测定,其中包括了刺孢小克银汉霉原变种和轮生刺孢小克银汉霉变种的各3株菌,它们的平均长度(bp)分别为890±7.5和915±7.6.这个结果也支持了我们在这两个分类群可以互相配合的情况下仍将它们作为两个不同变种的处理.这两个分类群虽然已被发表多次,但它们的描述和绘图均过于简单而未能充分显示出它们的区别性特征,因此我们在本文中再次作了描述并再次提供了详尽的线条图和显微照相.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号