摘要:

In south‐eastern Arizona, heterostylous (often trimorphic) populations ofOxalis alpina(Rose) Knuth are visited most commonly by females of the solitary beeHeterosarus bakeriCockerell. Bees collect pollen from flowers and are presumed to be the major pollinators ofO. alpinain this region. Analysis of pollen loads from the corbiculae ofH. bakerisuggests that individual bees may specialize temporally on different floral forms. However, the apparent preferential collection of pollen probably results from spatial segregation of morphs and the localized foraging behaviour of bees rather than preference on the part of individual bees for particular stylar forms. As a group, bees appear to visit floral morphs ofO. alpinaindiscriminately, even though individual bees may have a preponderance of pollen from one morph type. Despite spatial segregation leading to pollinator flights between members of the same incompatibility group, capsule and seed production in populations ofO. alpinais high for all forms. Loss of the mid form in some populations cannot be attributed to pollinator preferences for individual style morph

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb0085.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The literature on terminology of stomata and stomatal development is reviewed and the terminology rationalized. The classification of developmental types and of the developing cells should not be combined with the morphological classification of mature stomatal complexes. The cells involved in the development should be distinguished on the basis of their origin and position in the developing stomatal complex, and not on the basis of their future form and appearance. It is unsound to distinguish any kind of cell only on the basis of a presumed future division by which it is replaced by its two daughter cells.Development of stomata begins with the formation of a stomatal meristemoid by an unequal division of a protodermal cell. A meristemoid may divide unequally to produce a new meristemoid and a mesogene cell. Stomatal meristemoids eventually function as guard‐cell mother‐cells. The adjective perigene is restricted to those cells that have arisen by divisions of protodermal cells surrounding the future stoma. The undivided cells surrounding protodermal cells should be termed agene cells, and not neighbouring cells, a term which should be restricted to morphological terminol

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb0093.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

A new subsection,PandanussectionCauliflorasubsectionPaniculiflora, is described to containP. halleorum, on the grounds of the paniculate structure of its staminate inflorescence, a feature not known elsewhere within the genusPandanus. Both leaf anatomy and pollen morphology appear to support this taxonomic separation.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb00346.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The pollen morphology of 38 representative species and varieties within the genusCoffeaL. is described. Eight pollen types, placed in two major groups, have been identified on the basis of the number of colpi, colpus characteristics, exine morphology and pollen size. Differences in pollen structures of the species studied do not correspond to present taxonomic groupings, but support a current proposal to place some of the species in the genusParacoffeaLeroy. Among the four sections in the genus, the sectionEucoffeacontains a high degree of pollen polymorphism.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb00347.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Eucalyptusis a large genus in which hybridization may produce populations which present taxonomic difficulties. A small group of plants, apparently morphologically intermediate betweenEucalyptus paucifloraandE. radiata, was studied in an attempt to determine whether hybridization was occurring, and to investigate the use of different techniques of analysis (morphological, chemical and numerical). Taken as a whole, the data from adult and seedling morphology, flavonoid composition, and volatile oil composition of the plants studied prove that they are indeed hybrids between the two species ofEucalyptus; however, these data also indicate some interesting problems in the application of some of these techniques to this particular situation.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb00348.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Flowers of 34 species, representing 4 of the 6 genera of the morphologically diverse South American subtribe Hyptidinae and including members of many of the sections of the genusHyptisare investigated. Floral anatomy is basically uniform, with some minor variations which are mainly related to differences in flower size.Marsypianthesdiffers from the other genera in that the style is fused to the ovary, the hypogynous disc is relatively massive, and there are 12 or 13 calyx traces rather than the usual number of 10. The stylopodium, which is characteristic ofEriopeand certain sections ofHyptis, is a fold of stylar tissue which develops in the bud prior to opening of the flower and is probably an abscission layer.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb00349.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Transfusion tissue is universal in leaves of gymnosperms. It is composed of three kinds of cells: thick walled tracheids, parenchyma and albuminous cells. In this paper a comparative account is given of transfusion tissue in 82 species. Differences in transfusion tissue can be classified into 7 groups according to the distribution pattern of tracheids, the different characteristics of secondary walls and in some cases the occurrence of accessory transfusion tissue. The groups are:Pinus‐type;Pseudotsuga‐type;Tsuga‐type;Cupressus‐type;Texas‐type;Araucaria‐type, andCycas‐type. The phylogenetic relationships of various taxa of gymnosperms is discussed on the basis of these different kinds of transfusion tissue. Brief remarks on transfusion parenchyma, sclerenchyma and accessory transfusion tissue a

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1981.tb00350.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY