摘要:

The value of the leaf epidermis, particularly of the glandular trichomes, in the identification and classification ofCombretumsubgenusCombretumin the African continent is assessed. The peltate hairs (‘scales’), found in every species of this subgenus, show a wide range of anatomy and have proved extremely valuable in assessing taxonomic relationshipS. In general, differentiation by these means is at the sectional level, and the species are treated under the 22 sections now recognized in Africa. It may be concluded that the systematic value of the scales is at least as great as that of any other organ in the subgenus, and in a great number of cases valuable indications have been obtained for the first time. In an appendix three new sections are descri

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01962.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Examination of the pollen morphology, floral morphology and anatomy, and vegetative anatomy ofEmblingia calceoliftoraF.Muell.leads to widely divergent views concerning its systematic affinities.Erdtman considers that pollen morphology showsEmblingiashould be referred to, or near to, Polygalaceae; the pollen grains are unlike those of Capparaceae, Goodeniaceae or Sapindaceae.Leins concludes thatEmblingiais probably allied to the Sapindaceae. He lists the following similarities: three‐carpellate, septate ovary with one axile ovule in each loculus; short androgynophore; eccentric, extrastaminal disk; reductions in corolla and androecium; ventral appendages to petals; spiral embryo and aril; bitegmic and crassinucellate ovules.Melville interprets the hood of the androgynophore ofEmblingiaas a third petal and the gland (‘disc’) as a reduced stamen fascicle; the floral parts show a tendency to adhesion such as is common in the Goodeniaceae.EmblingiaresemblesScaevolain general habit and hair type; the trimerous ovary, stigmatic vascular brush, and reniform seeds with curved embryos and complex vascular supply also suggest an affinity with Goodeniaceae.Metcalfe's examination of the leaf and stem anatomy ofEmblingiashows that the histological resemblance is closest to Goodeniaceae and next closest to Polygalaceae. Similarities to Goodeniaceae include minutely warty, unicellular hairs; branched sclereids; vascular bundles of leaf sheathed by inflated parenchymatous cells; deep‐seated origin of cork in stem; xylem forming a closed cylinder in stem, traversed by narrow rays; mostly solitary vessels with simple perfo

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01963.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

The Hawaiian genusBrighamia(Lobeliaceae) was published in 1868 as monotypic, and it long remained so, even though it occurs on four islandS. It is a spectacular herb with a simple, thickened, fleshy, stem 1–5 m tall, with the leaves terminal and crowded, and subtended by them are the fragrant, salver‐shaped flowers 12–15 cm in length. Further explorations have revealed new localities, mostly on the cliff faces of the windward sides of the islands. The present investigation has revealed significant differential characters in the calyx lobes, the flower colour, the hairiness of the filament tube and the anther connective, and the nature of the seed testa. Hence, the following new taxa are described:B.citrinavar.napaliensis, B.rockiiandB.rockiiformalongilobaandB.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01964.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Representatives of theTradescantia geniculataalliance (genusGibasisRafin.) in cultivation at Kew display considerable cytological and morphological diversity. Chromosome complements consist of either large or small chromosomeS. Plants with small chromosomes have either 2n= 16 or 2n= 32, and all form only bivalents at meiosis and have presumed basic numbers ofx –8 andx= 8 or 16 respectively. The 2n= 32 accessions are considered to representT.geniculatain its strict sense; the identity of the 2n=16 plant is uncertain. Plants with large chromosomes have either 2n= 16 or 2n = 20 and each forms quadrivalents to the extent that they can be considered as cytological autotetraploidS. Basic numbers are thenx= 4 andx=5, the lowest yet recorded for theCommelinaceae.The identity of thex= 4 species is uncertain. Thex =5 plants are readily identified asT.karwinskyan

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01965.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Tubers in all five species develop from the hypocotyl region of the seedlingS. A perivascular cambium arises cutting off mainly starch‐storing parenchyma and collateral vascular bundles to the inside. A phellogen gives rise to cork on the outside. Between the two cambial layers there may or may not be layers of parenchyma, not storing starch but containing raphides. The vascular bundles consist of xylem with vessels, scalariform tracheids and parenchyma; and phloem, with sieve tubes and parenchym

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01966.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Some Lower Carboniferous seed megaspores have triradiate sutures–unequivocal evidence of their being arranged in a tetrahedral configuration. This type of tetrad arrangement is unknown in the ovules of modern gymnospermS. Some of the fossil tetrads consist of one large functional megaspore and three smaller abortive spores attached at the apex of the large one. All four spores have an exinous covering.Spores arranged in tetrahedral tetrads, and hence with triradiate sutures, are characteristic of many modern and fossil free‐sporing pteridophyteS. In possessing this feature the fossil seed megaspores are more similar to the spores of these pteridophytes than to the megaspores of modern gymnospe

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01967.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Previous records ofPyramimonas tetrarhynchusare examined, and a morphological variant is designated as var.lobata var.nov.The species was studied by light microscopy using cultured material, as a supplement to investigations with the electron microscope published separately. Particular attention was paid to aspects of cell symmetry at various stages of division.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01968.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

The taxonomy of isolates referred toSaprolegnia asterophorade Bary has been investigated. Two new species are described andSaprolegnia asterophorahas been re‐defined. These three species are regarded as segregate species within an aggregate and are placed in a new genus of the Saprolegniaceae,ScoliolegniaDic

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1969.tb01969.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY