摘要:

A comparative account is given of the anatomy of 28 species, three varieties and one hybrid of the Central and South American genusEscalloniaMutis ex L.f. (classified variously in the Saxifragaceae, Escalloniaceae or Grossulariaceae). On anatomical grounds, five species groups can be distinguished. These are discussed in relation to the recent monograph ofEscalloniaby H. Sleumer.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01744.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

By means of serial sections and cinematographic methods the vascular system in the stems of certain Pandanaceae is analyzed, in both mature axes and developing crowns. This serves to establish the three‐dimensional basis for the bi‐ or tri‐polar vascular bundles which are apparent in single sections of stems of all species of Pandanaceae which so far have been examined. The basic “R/iap/s‐principle”, which characterizes woody monocotyledons, is here expressed in a distinctive way which can be seen as an important developmenta

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01745.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The distribution of the phloem in relation to the xylem was examined in the stem ofHibiscus cannabinusL. with reference to a report in the literature that this species has internal (intraxylary) phloem, a feature not previously observed in the Malvaceae. In the present study, the stem was found to have phloem only outside the xylem (external or extraxylary phloem). In the protophloem, the sieve tubes are obliterated while the internode elongates and the associated cells become fibres with thick secondary walls. Fibres occur in the secondary phloem also. As seen in transections of stems, the secondary xylem forms a continuous ring. The primary xylem extends in the form of arcs into the pith. The tracheary cells of the protoxylem become crushed or completely obliterated in elongating internodes. The associated parenchyma cells either retain thin walls or develop secondary thickenings.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01746.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A detailed comparison of the vegetative and reproductive structures inLaurus nobilisandL. azoricais presented. Most of the characters used by authors to differentiate the two species show a marked degree of overlap. The only characters for which absolute differences could be demonstrated were the leaf tomentum and chromosome number. The fossil record is discussed. None of the taxa referred toLauruscan be accepted as representatives of the genus. However, an examination made of leaf‐remains known asLaurophyllum abchasicumestablished that these belong to the genusLauru

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01747.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The foliar epidermis and cuticle ofStaurogyne longifolia(Nees) Kuntze,Elytraria acaulis(L.f.) Lindau var.acaulis, E. acaulisvar.lyrata(Nees) Bremek. andNelsonia campestrisR.Br, have been investigated, revealing broad similarities with those of the rest of the Acanthaceae; the presence of diacytic stomata in the Nelsonioideae is evidence of its affinity with the Acanthaceae in general‐, while the presence of panduriform glandular hairs and the absence of the cystoliths in Nelsonioideae indicate its particular affinity with the Thunbergioideae. Substantial evidence is provided to support the retention of Nelsonioideae as a subfamily of the Acanthaceae, rather than its transfer to the Scrophulariacea

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01748.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The stomata in the six Indian species ofPortulacaL. are paracytic and predominantly dicyclic, completely enclosed at their polar ends by the subsidiaries, and mesogenous dolabrate and basipetal in differentiation except inP. oleracea, where they are diffuse in origin. The subsidiaries of the outer cycle develop directly from the stomatal meristemoids. The leaves are amphistomatic except inP. quadrifida, where they are epistomatic. The stomata are mostly orientated atc.90oto the midrib of the leaf, but inP. oleraceathey are irregularly orientated. The origin of the stomatal orientation appears to be genetically regulated rather than epigenetic. InPortulaca, as in some other angiosperms, the epidermal pattern of the costae is similar to that of the interstices, i.e. stomatiferous with nearly isodiametric cells. This is considered to be due to prevention by the thick chlorenchyma, characteristic of these plants, of the stomatal inhibitory stimuli originating in the vascular tissues from reaching the epidermis.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01749.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01744a.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY