摘要:

The results of a chemotaxonomic survey of the Rosaceae for the occurrence of flavone C‐g!ycosides, together with a general literature review of Rosaceae chemotaxonomy, are compared with the hypotheses of classical botanical taxonomy relating to the origins and evolution of the subfamilies of the Rosaceae. A tentative phyiogenetic scheme is presented, based upon all available taxonomic evidence. The chemotaxonomic data is consistent with the hypothesis that the Pomoideae are of allopolyploid origin, produced by ancient hybridization between primitive forms of the subfamilies Prunoideae and Spiraeoideae, although the possibility cannot completely be excluded that primitive Spiraeoideae only were involved. Flavone C‐glycosides, hitherto thought to be restricted in the Rosaceae toCrataegus, have also been detected in the following genera:Pyracantha, Osteomeles, Aronia, Hesperomeles, Malacomeles, Chamaemetes, Dichotomanthes(Pomoideae);Quillafa(Spiraeoideae);Agrimonia, Adenostoma, doubtful traces inSanguisorba, Potentilla, Alchemilla(Rosoideae). None could be detected in the Prunoideae. The chemotaxonomic evidence supports the hypothesis thatQuillajais a relict of an apocarpous ancestor of the Pomoideae and thatDichotomanthesis a relict of the primitive Pomoid

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01629.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The detailed morphology and anatomy of the aerial parts of two subspecies ofPsiadia salviifoliaBaker (Compositae), collected in Madagascar, are described. Certain histological differences are noted between the trichomes of subsp.salviifoliaand subsp.mandrarensiswhich indicate a means of differentiating between the two subspecies.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01630.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

When leaves of the Taxodiaceae are placed in 10% chromium trioxide at 40oC for 6–24 hours, a macerated cuticle is obtained. Examination of the inner surface of these cuticles by the scanning electron microscope reveals a consistent steady state structure, which we show to be usable for comparative study. The variations of the sculpture, both within the same leaf and throughout the family, are presented. Both the structural and the evolutionary significance of the features are discusse

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01631.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Epidermal and cuticular characters of 30 taxa ofEphedra(including 24 species and six additional varieties) are described and their taxonomic value is discussed.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01632.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Complete elimination of a node‐internode alternation in the branchlets ofCharais reported for the first time. Adult plants ofC. vulgarisvar.inconnexa(T. F. Allen) R. D. Wood from Canada were observed during the early part of the growing season to have isolated branchlets and entire whorls of branchlets which lacked nodes, consisting instead of a monopodial series of four to six undifferentiated segments. In plants of the same taxon from Germany all branchlets completely lacked nodes. During the summer months, however, all new branchlets developed the typical node‐internode alternation. A developmental explanation is put forward for this phenome

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01633.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY