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.
(1) The ability to produce cephalodia is usually a genus-specific character in lichens. (2)Lecidea shushanii Thoms., is a member of the genusTephromela, closely related toT. aglaea. It is not clear, whether or not the cephalodia of this taxon are true cephalodia or colonies of epiphytic cyanobacteria and whether or notLecidea shushanii is an independent species. (3)Lecidea dovrensis Nyl., is, in contrast to the traditional concept, not conspecific withLecidea alpestris Sommerf., but an earlier name forLecidea pallida Th. Fr. (4)Lecidea dovrensis is described in some detail. Chemically the species is characterized by the presence of isousnic acid (previously unknown in lecideoid lichens). It is restricted to areas north of the 60th parallel with an oceanic climate. (5) In connection with the attempt to clarify the taxonomic relationships ofLecidea dovrensis, figures of ascus apical structures of the following species are given (marked by an asterisk are genera where we found discrepancies with published data):Austrolecia antarctica, Catillaria chalybeia, Lecidea alpestris, L. caesioatra, L. limosa, Lecidoma demissum, Koerberiella wimmeriana, Micarea assimilata, M. crassipes, M. melaenida, M. prasina, Pilophorus robustus, Placodiella olivacea, Placolecis opaca, Porpidia trullisata, Protoblastenia rupestris, Psilolechia lucida, Psorula rufonigra, Squamarina gypsacea, Xanthopsorella texana. (6) Among crustaceous lichens we find no groups related toLecidea dovrensis. We supportTimal's concept of including this species in the genusPilophorus. Pilophorus, as well asLecidea dovrensis is characterized by the same ascus type, by a similar structure of thallus, cephalodia, paraphyses, and ascocarp (although there is no pseudopodetium developed inLecidea dovrensis), and the presence of isousnic acid. In addition, both taxa are restricted to cool oceanic climates and non-calciferous substrates. The following combination is proposed:Pilophorus dovrensis (Nyl.)Timdal, Hertel & Rambold, comb. nova. (7) The species of theLecidea alpestris-group form an independent genus, probably near toAustrolecia Hertel.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

2.
Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels.,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt.,A. rosea Greene, andA. umbrinella Rydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifolia Rydb.,A. arida E. Nels.,A. confinis Greene,A. scariosa E. Nels.,A. foliacea humilis Rydb.,A. concinna E. Nels., andA. viscidula E. Nels. are considered to represent F 1 hybrids.  相似文献   

3.
Quantitatively evaluated C-banded and conventional karyograms are presented for the related speciesScilla bifolia subsp.danubialis Speta,S. drunensis (Speta)Speta, andS. vindobonensis Speta. On the basis of banding patterns and karyotype structureS. bifolia subsp.danubialis (2n = 18, 2×) andS. drunensis (2n = 36, 4×) are quite similar, whileS. vindobonensis (2n = 18, 2×) is entirely different. There is a moderate degree of karyotypic variation withinS. bifolia subsp.danubialis andS. drunensis. However, inS. vindobonensis karyotypes and banding patterns are almost completely stable over a geographical range of about 500 km. The present results confirm the recent taxonomic separation ofS. vindobonensis fromS. bifolia, and suggest a considerable phylogenetic distance between these two diploid species. The results are discussed with reference to the morphological characters of the species and their geographical distribution.Evolution ofScilla and Related Genera, II.Dedicated to Univ.-Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 60th birthday.  相似文献   

4.
Three species of the genusPicris L. are native in Tropical Africa:P. abyssinica Sch. Bip. (Ethiopia),P. xylopoda Lack, spec. nova (Nigeria, Ethiopia) andP. humilis DC. (Senegal, Mali). There are indications that the two perennial species,P. abyssinica andP. xylopoda, are related to and have evolved from a primitive Central Asiatic stock in a manner parallel to many African species ofCrepis L.P. humilis, on the other hand, is a small annual plant with a high number of derived characters. The introduced species of European origin growing south of the Sahara are briefly mentioned.  相似文献   

5.
Leucojum plants from the Ionian Islands (Western Greece) until now have been confused with the SW. to W. MediterraneanL. autumnale L. from the subgenusAcis. They are conspecific withL. valentinum Pau from subgenusRuminia, described from E. Spain (near Valencia).L. autumnale has 2n = 14 chromosomes, whileL. valentinum from the Ionian Islands has 2n = 16 chromosomes. The morphology, cytology, distribution and ecology of the species is demonstrated and compared with allied taxa.
Beiträge zur Flora Ionica V. Der folgende Beitrag basiert auf Untersuchungen, die parallel zu denen vonD. & U. Müller-Doblies durchgeführt wurden (vgl. S. 117 dieses Heftes). Die Ergebnisse ergänzen sich bzw. stimmen überein. Das interessante Bild der verwandtschaftlichen Beziehungen der mediterranenLeucojum-Sippen wird so abgerundet und bestätigt. Damit erscheint der parallele Abdruck der beiden Veröffentlichungen in einem Heft unserer Zeitschrift gerechtfertigt (Herausgeber).  相似文献   

6.
Filaments ofPhymatodocis nordstedtiana Wolle were isolated from a sample of a Texan lake. Cultures were established and examined by light and scanning electron (SEM) as well as transmission electron microscopy (TEM). It is shown that the pores apparent on light microscopical examination are not of the cosmaroid type as expected. TEM examination disclosed that they are similar to those found in the generaClosterium Ralfs andPenium Bréb. Furthermore, it could be demonstrated by light and SEM microscopy that the primary cell wall is shed during cell division. The remaining secondary cell wall of the mature cell consists of interwoven bands of parallel microfibrils. A conspicuous overlap of the semicell walls clearly denotes the isthmus region. The significance of these deviations unusual for desmids is discussed. Suggestions are made that the taxonomic position ofPh. nordstedtiana should be re-evaluated.  相似文献   

7.
Verrucaria schaereri (Fr.)Nyl. is accorded generic status asPlacocarpus Trev. emend.O. Breuss. The main differences between the two genera concern the thallus anatomy and the spores which are halonate inPlacocarpus. The following new combinations are proposed:Placocarpus schaereri (Fr.)O. Breuss andPlacidiopsis cinerascens (Nyl.)O. Breuss.  相似文献   

8.
The esterase and peroxidase patterns in five varieties ofAegilops caudata (genome type C) andAe. comosa (genome type M) were studied in order to elucidate the phylogenetic relationships within and between the two groups. The electrostarch gel electrophoresis technique was applied to extracts of shoot and root of 4-day-old seedlings, and the electropherograms were evaluated by gel densitometer traces. Inspite of considerable isozyme polymorphism, closer relationships in the banding patterns were found between different varieties of a single species than between varieties of the two different species. Esterase and peroxidase patterns of the twoAe. caudata varieties (caudata andpolyathera) are very similar and prove their close phylogenetic relationship. The isozyme affinities withinAe. comosa varieties are illustrated by the seriessubventricosa—biaristata—thessalica. The latter endemic variety has quite a number of characteristic bands and is relatively isolated. Altogether, the electrophoretic data agree well with morphological and cytological similarities (Zhukovsky 1928,Eig 1929,Karataglis 1973, 1975b).  相似文献   

9.
TheThymus teucrioides Boiss. & Spruner aggregate is revised and the following new taxa, all from the alpine zone in the Greek mountains, are described:Th. leucospermus Hartvig from the calcareous mountains of Pindhos and Mt Parnassos in Sterea Ellas,Th. rechingeri Hartvig with the subsp.macrocalyx Hartvig from calcareous mountains in Sterea Ellas and N Peloponnissos, andTh. teucrioides subsp.alpinus Hartvig from the serpentine areas of N Pindhos. In the variableTh. teucrioides s. str. many characters have turned out to be markedly geographically correlated and many local populations can be distinguished by a particular combination of characters.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.  相似文献   

10.
Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.  相似文献   

11.
Asperula visianii Korica is described as a new stenoendemic species from the small Central Dalmatian island of Svetac (near Vis). It differs in several morphological features (which remain constant in cultivation) and in its ecology from the closely relatedA. staliana Vis., endemic on the nearby island of Bievo.
  相似文献   

12.
The following new hybrids are described:Euphrasia ×dilata = E. hirtella Jordan exReuter ×alpina Lam.;Euphrasia ×trikoviana = E. tricuspidata L. ×rostkoviana Hayne. The chromosome number ofEuphrasia tricuspidata L. has been established for the first time: 2n = 22.
  相似文献   

13.
Significant increase of pod production occurs inLupinus palaestinus Boiss. andL. pilosus Murr. following insect visits. The cause of this increase is investigated through (1) examination of the biology of pollination, (2) examination of pod production under various pollination conditions, (3) examination of cross pollination by genetical markers. All data strongly suggest that Insect Induced Self Pollination is the main factor in the increase of pod production of these species in nature.  相似文献   

14.
Lupinus pilosus Murr. andL. palaestinus Boiss., are both East Mediterranean annuals, greatly resemble each other in morphology, and have the same chromosome number (2n = 42). Some fertile hybrids can be formed by artificial hybridization or under unusual habitat conditions. Isolation in nature between the species is, however, maintained by prevalent selfing, partial reproductive barriers and genic imbalance, together with differences in ecological requirements. It is suggested that this speciation pattern which includes little morphological and hardly any chromosomal divergence might have occurred in other cases of edaphic vicariants too.  相似文献   

15.
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   

16.
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   

17.
The chemical variation inLecanora epibryon andL. subimmersa, two species of theL. subfusca group, has been examined. In both species the chemical differences are correlated with geographical distribution, but not with morphological differences. As a consequence the chemotypes are recognized at subspecific level. InL. epibryon three chemical races are segregated according to the various chemosyndromes present. Subspeciesepibryon, containing atranorin and triterpenoids, occurs in the northern hemisphere and South America, while the other two subspecies occur only in the southern hemisphere. The subsp.broccha (Nyl.)Lumbsch, comb. nova, contains atranorin, the stictic acid and the 2,5,7-trichloro-3-O-methylnorlichexanthone chemosyndromes, while subsp.xanthophora Lumbsch, subsp. nova, is similar but lacks the stictic acid chemosyndrome. Two chemical races occur in the pantropical speciesL. subimmersa. While subsp.subimmersa contains atranorin and zeorin, subsp.ramboldii Lumbsch & Elix, subsp. nova, contains an additional ten chlorinated xanthones.L. impressa is reduced to synonymy toL. subimmersa.  相似文献   

18.
The biosystematics of theFestuca violacea group (F. rubra subsp.violacea sensuHackel) in the Eastern Alps is studied.F. picturata Pils (=F. picta Kit. exSchultes nonJ. F. Gmelin) is confirmed as diploid, whereas the chromosome numbers forF. nitida (diploid),F. puccinellii (hexaploid), andF. norica (diploid, tetraploid and hexaploid) are reported for the first time. Details of morphology, leaf anatomy, and epidermal structures now allow a better separation of these species; new maps illustrate their distribution. Karyological, chorological, morphological, and anatomical data form the basis for a discussion of the phylogeny of theF. violacea group and its position withinF. rubra s. latiss.
  相似文献   

19.
Alginate beads containing axillary buds of in vitro-grown gentian (Gentiana scabra Bunge var. buergeri Maxim.), were successfully cryopreserved following 2 step-preculture with sucrose and desiccation. The optimal preculture conditions were as follows: axillary buds were excised from in vitro-grown gentian plants and precultured on semi-solid Murashige and Skoog (MS) medium containing 0.1 M sucrose for 10 days (25 °C, 16-h photoperiod) (first step). This was followed by incubation on semi-solid MS media containing 0.4 M (1 day) and then 0.7 M sucrose (1 day) (second step). After preculture, the buds were encapsulated in alginate beads and desiccated aseptically on silica gel for 9 h to a water content of 10% (fresh weight basis), followed by immersion in liquid nitrogen (LN). With this protocol, 87% of the gentian buds survived exposure to LN and showed normal development of shoots and roots in vitro and in vivo. Depletion of NH4NO3 in the regeneration medium did not improve survival following desiccation and exposure to LN. The results show that 2 step-preculture with sucrose is effectively applicable in encapsulation–desiccation based cryopreservation of gentian axillary buds. This preculture can replace the conventionally used lengthy cold-hardening treatment and is useful for routine cryopreservation of gentian germplasm.  相似文献   

20.
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   

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