摘要:

Studies on the growth ofArchontophoenix cunninghamianain two separate populations show that this species establishes only a narrow apical meristem complex before rising above ground This complex continues to expand in girth as it rises, until at a height of about 12 m its girth becomes fixed. The lower regions of the trunk expand, more than equalling the expansion at the apex, producing at least a 20‐fold increase in volume. Anatomical observations show that this expansion, termedsustained primary growth, is due to cell enlargement and cell division in the ground tissue, and is relatively uniform along the radius of the stem. When the apex reaches a height of 12 m, sustained primary growth ceases abruptly, fixing the taper of the trunk. Subsequent growth produces a cylindrical top on this tapered base.These results are considered in the light of a review of earlier work on palm growth. The determinate nature of this type of arborescence is discussed, and brief reference is made to its evolutionary statu

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01374.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae andTricyrtis latifolia.Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01375.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The arguments lor the conspecificity of the tetraploid taxa inVulpiasectionVulpia sensuCotton&Stace are discussed.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01376.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Fuchsia lampadaria, a new species from Sierra Nevada de Santa Marta, Northern Colombia, is described and illustrated.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01377.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Two new species of Campanulaceae from New Guinea are described,Lobelia victoriensisandWahlenbergia papuana.Keys to and enumerations of the species of both genera of New Guinea taxa are provided.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01378.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

A new subspecies of the West AfricanEncephalartos barteriis described from plains on the Jos Plateau of northern Nigeria.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01379.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1978.tb01380.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY