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 34 毫秒
1.
Desmarestia antarctica Moe & Silva, a new species from the Antarctic Peninsula and the Scotia Arc, is distinguished from all other ligulate members of the genus by the arrangement of zoosporangia, which are produced together with paraphyses in a raised sorus. Among all species in the genus, onlyD. anceps Montagne shares this feature.Desmarestia antarctica is the first species of the genus for which an endophytic gametophyte is demonstrated, the usual host beingCurdiea racovitzae De Wildeman, a red alga of the familyGracilariaceae. The sporophyte contains only a moderate concentration of acid compared to Northern Hemisphere ligulate species, while physodes that probably contain polyphenolic compounds form noticeable speckles and dark margins in preserved plants. Often more than one axis arises from a single holdfast, probably as the result of compounding rather than proliferation.Dedicated to Prof. DrLothar Geitler on the occasion of the 90th anniversary of his birthday.  相似文献   

2.
Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.  相似文献   

3.
Phagnalon rechingeri spec. nova from S Baluchestan (Iran) is described as a species new to science and illustrated; its relationships to other species of the genus, in particular to thePh. woodii group from S Arabia, are discussed.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday.  相似文献   

4.
Anew osteostracan genus and species,Victoraspis longicornualis n. gen., n. sp., is described based on material from Rakovets’, present day Ukraine. This new taxon shares characters with the two generaStensiopelta Denison, 1951 andZychaspis Janvier, 1985. A phylogenetic analysis supports the position ofVictoraspis as the sister group to a monophyleticStensiopelta, while the interrelationships of the various species ofZychaspis are poorly resolved. A morphometric analysis is carried out in an attempt to further resolve the taxonomic affinity. This analysis groups all examinedZychaspis species closely together, and further supports the establishment ofVictoraspis as separate genus.   相似文献   

5.
6.
A new genus,Aurantiosporium Piepenbring, Vánky & Oberwinkler (Ustilaginales), is proposed for the smut speciesUstilago subnitens Schröter & Hennings onScleria melaleuca Reichb. The soral morphology, teliospore development, the ultrastructure of the teliospore wall and teliospore germination ofAurantiosporium subnitens, studied on collections from Costa Rica, are described for the first time. The character set ofA. subnitens including intercellular teliospore development, spores in irregular groups and light coloured spore walls with numerous layers in TEM is neither known fromUstilago norCintractia nor any other smut species.Part 113 in the series Studies inHeterobasidiomycetes from the Botanical Institute, University of Tübingen.  相似文献   

7.
Cyclamen somalense Thulin & Warfa, spec. nova, the first member of the genus known from tropical Africa, is described from the Al Miskat Mts in NE. Somalia. The new species is closely related to the E. MediterraneanC. persicum Mill. The disjunct Mediterranean element in the mountain flora of northern Somalia, to whichC. somalense belongs, is believed to be largely a relict of Tertiary origin.  相似文献   

8.
A new genus ofCruciferae, Dolichorhynchus Hedge & Kit Tan (D. arabicus Hedge & Kit Tan) and a new speciesArabidopsis erysimoides Hedge & Kit Tan, both from northern Saudi Arabia, are described and illustrated. An addendum lists new Crucifer generic or species records for the Arabian peninsula.  相似文献   

9.
Microparacaryum (M. Pop. exH. Riedl)Hilger & Podlech is described as a new genus of theBoraginaceae-Cynoglosseae. It comprises the annual species hitherto included inParacaryum (DC.)Boiss. andMattiastrum (Boiss.)Brand. Distribution maps are given for all 3 genera.Microparacaryum consists of two species,M. salsum (Boiss.)Hilger & Podlech (M. s.) andM. intermedium (Fresen.)Hilger & Podlech (M. i.). ParticularlyM. i. is a very variable species, and most of the species formerly recognized belong here. Scattered all over the range of the genus, plants occur with nutlets exhibiting flat or incurved marginal wings, often in mixed populations. This fruit polymorphism is taxonomically treated by recognizing formae. In addition, the following new infraspecific taxa and combinations are described:M. i. var.intermedium formaparacaryoides Hilger & Podlech,M. i. var.stellatum (H. Riedl)Hilger & Podlech,M. i. var.stellatum formamattiastroides Hilger & Podlech,M. s. formamattiastroides Hilger & Podlech.
  相似文献   

10.
The author has proceeded with a cytotaxonomical study of the genusSideritis L. Chromosome numbers (mostly new) are reported for about twenty taxa from sectionEmpedoclea (Rafin.)Benth. This section occupies a very isolated position within the genus and has evolved quite independently.
  相似文献   

11.
Morphological data and results from scanning electron microscopy of seeds and pollen show thatNormania Lowe [syn.Solanum L. subg.Potatoe (G. Don)D'Arcy sect.Normania (Lowe)Bitter] (Solanaceae: Solaneae) should be considered as a distinct genus fromSolanum L. It has two species, one restricted to the island of Madeira [Normania triphylla (Lowe)Lowe] and the other to Tenerife and Gran Canaria [Normania nava (Webb & Berthel.)Franc.-Ort. & R. N. Lester]. These species are extremely rare and had not been found for about 100 years, untilN. nava was rediscovered in two different localities in Tenerife in 1973 and 1982.Normania triphylla was reported in two different places from northern Madeira in 1991. Both species have the highest conservation priority in the Macaronesian region.  相似文献   

12.
Seven flavonol glycosides were identified from the main taxa of theF. bruguieri complex. Of these, kaempferol 3-rhamno-galactoside, Quercetin 3-rhamnogalactoside and Quercetin 3-galactoside are new records for the genusFagonia L. and theZygophyllaceae s. str. The distribution of these flavonoid glycosides is discussed with respect to the morphology, chemosystematics, and possible phylogeny of the complex and the genus.Dedicated to Hofrat Univ.-Prof. DrKarl Heinz Rechinger on the occasion of his 80th birthday.  相似文献   

13.
Intergeneric crosses were made between representatives of the genomically-defined generaElymus, Agropyron, Elytrigia, Pseudoroegneria, andThinopyrum. The genomic constitution ofElytrigia repens, the type species ofElytrigia, is shown to be SSH, a genomic combination otherwise found only inElymus. The S genome ofPseudoroegneria has almost always a dominant influence on the morphology of the taxa of which it is a component.Wang (1989) showed that the J genome inThinopyrum and the S genome have considerable homoeology, with a mean c-value of 0.35 in diploid SJ hybrids. A genetic coherence from S to SJe, Je, JeJb, and Jb can be expected, agreeing with the continuous morphologic variation pattern observed. Because of the absence of morphological discontinuities between the taxa,Pseudoroegneria (S),Elymus (SH, SY, sometimes with additional genomes),Elytrigia (SSH, SSHX), andThinopyrum (SJ, SJJ, J) are best treated as a single genus,Elymus, following the generic concept ofMelderis in Flora Europaea and Flora of Turkey. The basic genomic constituents ofElymus will then be the S and/or J genomes.Agropyron, with diploids, tetraploids, and hexaploids based on the P genome is morphologically distinct from other genera inTriticeae. In a few species ofElymus andPseudoroegneria, a P genome is an additional constituent. In these cases the P genome has a negligible morphological influence. Therefore, it seems reasonable to maintainAgropyron as a separate genus.  相似文献   

14.
The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.  相似文献   

15.
A study of both silicified and nonsilicified specimens of Permian reticularioid brachiopods from South China suggests thatPermophricodothyris, a genus previously rarely reported from China, is actually very common and abundant in the Middle and especially Upper Permian of South China. This study also clarifies, for the first time, that many of the reticularioid brachiopod species previously described asSquamularia in fact belong toPermophricodothyris. The new data presented in this paper also allows a critical evaluation ofPermophricodothyris in relation to its closest allies:Phricodothyris, Squamularia, Bullarina andNeophricodothyris. The revision reveals that a total of 18Permophricodothyris species are present in the Middle and Upper Permian of South China, with only one species,P. squamularioides, having survived the Permian-Triassic mass extinction. Two species,P. grandis (Chao) andP. guangxiensis Han, Zhou & Wang, are redescribed here, providing critical new information on the morphology and taxonomy of these species.  相似文献   

16.
Statistical analyses and scatter diagrams illustrate for the polymorphic E. and SE. BrazilianDrimys brasiliensis a clear correlation between morphological variation and eco-geographical differentiation. This is backed by data on the (ultra)structure of the lower leaf surface. A new infraspecific taxonomy is proposed, andD. roraimensis andD. angustifolia are recognized as distinct species of the Guyana Highlands and S. Brazil, respectively. The affinities between these and other taxa of the paleopolyploid genus, its evolution and its position within the family are discussed.Dedicated to Prof.Lothar Geitler at the occasion of his 80th birthday.  相似文献   

17.
The chromosome numbers of the five European seagrasses have been determined in material from several sites along the coasts of the Atlantic Ocean, the North Sea and the Mediterranean:Zostera marina L., 2n = 12;Z. noltii Hornem., 2n = 12;Posidonia oceanica (L.)Delile, 2n = 20;Cymodocea nodosa (Ucria)Aschers., 2n = 14, 2n = 28;Halophila stipulacea (Forsk.)Aschers., 2n = 18. The difference in chromosome morphology betweenZ. marina andZ. noltii supports the division of the genus into two subgenera.  相似文献   

18.
The endemic New Guinean genusIschnea F. Muell. (Asteraceae, Senecioneae, Blennospermatinae) is revised and four species are recognized. Characters of special interest are tubeless ray florets, male disc florets, and secretory spaces in leaves. A principal component analysis is made on theIschnea elachoglossa F. Muell. complex which shows great variation. One new species,I. capellana Swenson, from the Star Mountains, is described. A key, illustrations, and distribution maps to all species are supplied.  相似文献   

19.
The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinus Benth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.  相似文献   

20.
Phyllagathis tuberculata King and two closely allied new species,P. magnifica A. Weber andP. stonei A. Weber, are described and illustrated. Within the genus, these species form a distinct and isolated group which is restricted to Peninsular Malaysia.P. tuberculata occurs in Perak (probably confined to G. Bujang Melaka),P. magnifica andP. stonei are found in the mountains on the Pahang/Selangor border (Genting Highlands, Gombak valley). The distinctive characters of the three species are listed and some general information relating to inflorescence morphology, tubercle anatomy, fruit structure and seed dispersal is provided.  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