摘要:

The chromosome numbers and morphological characteristics, including life–form, vegetative and floral measurements and pollen fertility, of 70 artificial interspecificVulpiahybrid plants and 49 artificial intergenericFestuca rubraagg. xVulpiahybrid plants are presented, together with comparable data from 60 artificialFestuca rubraagg. xVulpia fasciculataplants produced by R. Cotton. The inheritance of various characters is summarized. It is concluded that most characters of the tetraploidVulpia fasciculataare dominant over those of diploid species ofVulpia, but that most characters of the hexaploidFestuca rubraagg. are dominant over those of diploid and tetraploid species ofVulpia.In diploid x diploidVulpiacrosses the pubescent ovary tip is dominant to the glabrous state, but the inheritance of lemma pubescence is more complicated. The keeled lemmas ofV. fasciculataandV. pyramidataare dominant to the rounded ones of otherVulpiaspecies, but recessive to the rounded ones ofF rubraagg. Bearing in mind such generalizations as these, the parentage of wild hybrids should be capable of correct interpretation. The significance of the results in our understanding of the origin ofV. fasciculatais discusse

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01501.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Two taxa of early–floweringEuphrasiaoccur on the island of Gotland, Sweden, viz.E. striclaJ. P. Wolff ex J. F. Lehm. var.tenuis(Brenner) Jalas andE. strictavar.suecica(Murb.&Wettst. ex Wettst.) Karlsson comb. nov. They are restricted to hay–meadows and, being sensitive to grazing and competition from taller plants, are now disappearing because hay–making on seminatural grassland has lost its economic importance and is being abandoned. Field studies showed that var.tenuisis restricted to meadows of the Arrhenatheretalia type, var.suecicato aspects of Molinietalia which approach Mesobrometum. A statistical analysis of mass collections showed that the best distinguishing character between var.suecicaand var.tenuisis that glandular hairs on the leaves are absent or only occasional in the former; in addition, var.suecicahas smaller flowers and narrower leaves with a cuneate leaf–base. These differences remained in cultivated material. However, the leaf shape is greatly dependent on vigour and is difficult to use for diagnostic purposes. There is a great deal of variation among populations, especially within var.suecica.Investigation of herbarium material confirmed the results from the analysis of mass collections, and also suggested that introgression from var.tenuisinto var.suecicahas taken place. Var.tenuishas spread to Gotland, possibly as early as during the Iron Age when haymaking became important, whereas var.suecicamay have originated on the island by selection from eglandular, autumnal variants ofE.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01502.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A new arborescent species ofCroton, C. megalocarpoidesFriis&Gilbert, is described from the coastal semi–evergreen forest and bushland in S Somalia and E Kenya. Its taxonomic affinity with other African species is demonstrated, particularly the relationship toC. megalocarpusHutch., a montane E African species with which it has long been confused, and toC. mayumbenseJ. Léonard, andC. mubangoMull. Arg., two species from lowland forest and forest–savannah mosaic in W Zaire and surrounding countries. The phytogeographical position of the new species is briefly discu

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01503.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01504.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Steenisia, with 5 species in Borneo and the Natuna Islands, is proposed to be removed from the tribe Argostemmateae (Rubioideae – Rubiaceae) to the tribe Rondeletieae (Cinchonoideae s. str. – Rubiaceae). The contorted aestivation of the corolla, the structure of the testa, the general absence of raphides, and the type of placentation are characters indicating this position. A key and descriptions, distribution maps and illustrations of all species are provi

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01505.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The generic concept ofGelasineHerb. (Iridaceae) is reviewed, and the characters discussed in connection withSphenostigmaBak., a synonym ofGelasine.The reduction ofSphenostigmais further justified on account of overlapping features. A new species from Uruguay,G. uruguaiensisRav. sp. nov., is described and illustrated. This is shown to include two subspecies: ssp.uruguaiensis, and ssp.orientalisssp. nov. The chromosome number of the latter is 2n = 14.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01506.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Detailed studies of comprehensive herbarium material confirmed that the afroalpineCerastium adnivaleChiov. is too indistinctly delimited from the earlier describedC. octandrumHochst. ex A. Rich, to be given more than varietal rank. The restricted distribution of var.adnivaleon only some of the high mountains harbouringC. octandrums. lat. as well as results of experimental cultivation show that the reduced pubescence of the former cannot be due to environmental influence alone but must result from genetic differences. The derivation of var.adnivalefromC. octandrums. lat. is discussed.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01507.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Distribution of starch and lipids has been studied in upper and lower parts of tilt branches and vertical branches ofAzadirachta indica A.Juss.,Mangifera indicaL. andPolyalthia longifolia(Sonn.) Thw. Starch grains in tiltwood are smaller than in vertical wood. Their accumulation is considerably lower in upper tiltwood than in lower tiltwood and vertical wood. The rays and axial parenchyma contiguous to vessels show the highest lipid content in the upper tiltwood ofA. indicaandP. longifolia.The accumulation of lipids in axial and ray parenchyma of upper tiltwood is smaller than in lower tiltwood and vertical wood. Since we found that not only the upper wood but also the lower part of the tilt wood is different from normal wood, we would like to suggest that the entire new wood of a leaning stem should be considered to be reaction wood.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01508.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01509.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Three morphological stages ofGeotrichum candidum, viz. the mycelium, a cylindrical spore type, and an ellipsoidal spore type, were subjected to qualitative and quantitative morphological and cytochemical analyses using scanning and transmission electron microscopy. Considerable variation in total cell shrinkage as well as cell wall thickness was found with fixation procedure and cell type. Cell walls were best preserved with simultaneous fixation in aldehydes and osmium whereas optimal preservation of the cytoplasm required sequential fixation. Mechanical pretreatment improved the visualization of ultrastructural details in the thick–walled ellipsoidal spores. Wall polysaccharides and cytoplasmic glycogen stained positively with periodic acid–thiosemicarbohydrazide–silver proteinate and with alkaline bismuth subni–trate. In all three cell types an electron–transparent wall region was sandwiched between outer and inner electron–dense and PAS–positive regions. Wall thickness in cylindrical spores corresponded to that of mycelium whereas ellipsoidal spores had a 1.7 times thicker wall and a 1.9 times greater wall volume than cylin

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1984.tb01510.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY