摘要:

The genusHypecoum(Papaveraceae) is subdivided into five sections. Two of them (sect.Chiazospermumand sect.Leptocarpaesect, nov.) are comprised in subgen.Chiazospermum, and three in subgen.Hypecoum(sect.Hypecoum, sectPendulaesect. nov., and sect.Mnemosillacomb, et stat. nov.). The morphology of the sections is discussed, and a hypothesis of the possible course of evolution within the genus is presented. Chromosome numbers are given for seven taxa.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01760.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Cerastium regeliihas a distribution confined largely to regions north of 70° N but has retained a strong short‐day (SD) response for primary flower induction despite the fact that it will hardly ever experience SD in a non‐frozen condition in its natural environment. However, like many other high‐latitude short‐long‐day plants it has also an alterntive long day (LD) pathway for floral initiation at low temperatures (<15°C). Floral primordia which are fully differentiated during SD have an absolute requirement for LD for flower development. The critical photoperiod for this LD response is about 16 h at 18°C and more than 20 h at 9°C. Plant morphology, including key characters for identification of the species, is greatly modified by environment and stage of plant development. At higher temperatures and LDC. regeliidevelops a striking resemblance to the sub‐arcticC. jenisejense. Based on examination of authentic herbarium material it is concluded that the latter is merely a high‐temperature morpho

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01761.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Justicia tetrasperma, a new species ofJusticiasect.Monechma, is described on material from Shaba in Zaire. Its capsules with four smooth and compressed seeds is a character combination in favour of an inclusion ofMonechmainJusticia.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01762.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Three new species,Ruprechtia maracaensis, Ruprechtia nitida, andTriplaris matogrossensisare described.Ruprechtia glaucais a poorly known species from the state of Bahia. Its relationship withR. laxiflorais discussed.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01763.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A new species ofSarcoglyphis, S. arunachalensis, from Arunachal Pradesh, India is described.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01764.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The distribution of 725 species and 4 subspecies of vascular plants in 522 grid squares of 50×50 km within Denmark, Finland, Norway and Sweden was analysed by detrended correspondence analysis (DCA) and two‐way indicator species analysis (TWINSPAN). Two phytogeographical gradients were recognized: a major gradient running both latitudinally and altitudinally, from southern and lowland areas to northern and mountain districts, and from southerly distributed species to alpine and northerly distributed species, and a secondary gradient running from eastern districts and easterly distributed species to western districts and westerly distributed species. The results are in agreement with previous recognized phytogeographical patterns within the considered area. Possible ecological and historical causes for these patterns are briefly discuss

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01765.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Alpha and beta diversity and habitat niche relationships of a poor, boreal mire was studied, based upon an ordination by detrended correspondence analysis and a subjective classification. The three first DCA axes were interpreted as variation along the following ecoclines: (1) mire expanse carpet–mire expanse hummock–mire margin hummock, (2) nutrient status: ombrotrophic–poor minerotrophic, and as a coenocline (3) associated with peat‐producing ability of the vegetation with an unclear ecological basis. The autecology of the 39 most frequent species was decribed with respect to these gradients. Alpha diversity patterns varied considerably between coenoclines. Beta diversity was always higher in the bottom layer than in the field layer. Habitat niche breadth was strongly correlated with species abundance, and separable into a frequency‐independent and a frequency‐dependent component. The former decreased from vascular plants to hepatics, and further toSphagnumspp. It was argued that the importance of interactions was high in the bottom layer, particularly amongSphagnumspp., but also among hepatics. Interactions among vascular plants was considered unimportant, except in hummocks. Plant strategies were discussed. The niche breadth approach was evaluated, and found fruitful, while niche overlap was considered to provide redundant information. The importance of each of (1) interspecific interactions, (2) destabilizing factors, (3) stress, and (4) chance, as structuring factors in boreal mires, is discussed. Boreal mires are considered to conform to the patch‐dynamics theory of non‐equilibr

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01766.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Anamorphs ofMycocalicium albonigrumandM. subtilehave been obtained in culture from ascospores, conidia collected in the field, and conidia produced in culture. The ontogenies of the conidiomata and conidia are described. Differences between the species with respect to cultural characteristics, septation of ascospores during germination, occurrence of chlamydospores and pyriform cells as well as ultrastructural details of conidiogenous cells and conidia were studied. Conidia are suggested to possibly be important in the dispersal of the species.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01767.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Whole cells ofMallomonas costataandMallomonas galeiformiswith complete scale and bristle complements present few problems for their identification by TEM. Individual scales however, such as those usually encountered in paleolimnology, have often been difficult to identify in isolation. Both species occur in collections from Ontario, Canada, butM. galeiformisis apparently more acidophilic thanM. costata. Several differences in structure of scales from both species are described which, if used as criteria for distinguishing between the two species, should facilitate identification of individual scales.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb01768.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY