摘要:

The development of the gametophyte of the fernDryopteris thelypteris(L.) Gray was observed under sterile cultural conditions in order to recognize those features necessary for computer simulation of the thallus geometry. Drawings of plants at 12‐hour intervals revealed that the triangular apical cell divides according to a left‐right alternation of cell plate orientation and that cell lineages derived from vegetative daughters of apical cell divisions progressively enlarge and are pushed to the sides and down along the thallus. A computer program was written that includes both biological rules and laws of physical constraints. The computerized plant passed through the typical filamentous, juvenile asymmetric, heart‐shaped and biauriculate stages. Descriptive morphology can become more objective by selection of simple traits as the criteria for an ontogenic reconstruction of an observed pa

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01757.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Leaf venation patterns of 150 species ofEuphorbiaare presented and their value as a diagnostic feature in the genus assessed. Based on the gross venation patterns, the species have been grouped into uni‐, bi‐, tri‐veined and special categories. The majority of the species studied belonged to the tri‐veined category, in which ornamentation of the veins and the course of traces in the lamina proved useful additional characters.Features such as the size of the areoles, the number of vein endings, and their further ramifications and composition in each areole varied in the same leaf or in different leaves of a given species. Furthermore, no direct correlation could be established between the areole size and the numbers of vein endings and tips per areole.Forty species possess a parenchymatous vein sheath. Globular chloroplasts showed up conspicuously in the sheath cells of a few species. Dilated tracheidal elements, localized on the venules or at the tips of vein endings, are characteristic of the xerophytic species. In some instances, correlation was apparent between plants grouped according to their venation patterns and thei

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01758.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The stem and root anatomy ofG. andersonii, G. macrophyllusandG. velutinusfrom the peat‐swamps of Sarawak is compared. Sufficient anatomical differences exist to differentiate the four species. The main distinguishing anatomical features between the stems are the cork cells, the nature and relative quantity of cortical sclereids and the presence or absence of lignified pith parenchyma. In differentiating between the roots ofG. andersonii, G. macrophyllusandG. malayanus. theprincipal features are the cork cells and the relative quantity of cortical sclereids. In addition, the medullary rays ofG. macrophyllusroot in transverse sections are noticeably broader in the xylem towards the phloem than those of the other specie

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01759.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The structure of the leaf epidermis ofBombax ceibaL. is described. Leaves of this plant have been generally reported to be hypostomatic. The present paper reports that on the upper epidermis up to eight rows of stomata are present along either side of the midrib. Development of the stomata is typically of the mesogenous anisocytic trilabrate type, but tetralabrate initials are also reported.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01760.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The three investigated species ofCyperusL. subgen.Juncellus(Griseb.) C. B. Clarke show anatomical differences in the leaf pertaining to the number of vascular bundles and bundle sheaths, size of silica‐cells and their wall thickness, while those of subgen.Mariscus(Gaertner) C. B. Clarke segregate into two primary groups depending on the presence or absence of a distinct hypodermis; and the species within each group are further differentiated on the basis of the presence or absence of air‐cavities, the number of vascular bundles and their pattern of arrangement in the leaf. The interspecific differences observed within the genusLipocarphaR. Br. concern the size of the interstomatal cells and the number of vascular bundles and bundle sheaths of the leaf. Keys for the identification of the species in each genus and subgenus are given separat

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1974.tb01761.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.tb01756.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY