摘要:

The Inflorescence ofEUCALYPTUSand its Interpretation. —The inflorescence in the genus Eucalyptus is apparently quite variable. Therefore, in the floral organisation morphologists have identified four different types: 1) solitary flowers; 2) umbel; 3) panicle; 4) corymb (fig. 1). The inflorescence called umbel may also appear under the following different aspects: a 3-flowered umbel (which is to be considered as a cyme); an umbel with pedicellate flowers; an umbel with sessile flowers (which is therefore a head) (fig. 2). Blakefirst (1953) thought, that the 3-flowered umbel was a simple dichasium, and he pointed out that the other types of inflorescences were branched and highly modified dichasia (figs. 4–2). This hypothesis has been confirmed and enlarged byPryor(1954)and Carr&Carr(1959) after a more detailed study of the developmental morphology of the inflorescence and mainly of the characters of bracts (figs. 10–2). Their studies proved that all the inflorescences (umbels, heads, panicles, etc.) are modified dichasia; even the solitary flower is a dichasium reduced to the terminal flower of the main axis (fig. 12). Therefore the dichasium, according toBlake,is the fundamental structure of all the inflorescences of Eucalyptus.

ISSN:0017-0070    

DOI:10.1080/11263506309430189

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Embriology ofCODIAEUM VARIEGATUM(L.) Blume var.PICTUM(Lodd.) Müll. —The development of the female gametophyte has been studied inCodiaeum variegatumvar. pictum.The gametophyte has been found to be monosporic, five-nucleate, of theGarciniatype, and not four-nucleate, of theCodiaeumtype, as established byArnoldi.

ISSN:0017-0070    

DOI:10.1080/11263506309430190

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Factors modifying the sex ratio inCANNABIS SATIVA L. — Given our lack of knowledge on the effect of age of seed and density of sowing on the sex ratio inCannabis sativaL., over65.000hemp stalks were examined during the years1959–2.These plants were sexually differentiated and were harvested from plots distributed in a randomized block. In each experiment it was found that the number of plants per square meter (which varied from 42,01 to 226,01) did not influence the sex ratio in spite of evident manifestations of natural selection due to this factor. On the contrary, alterations in the sex ratio in favour of the ♀ plants were caused by the age of the seeds, especially if plants obtanied from seeds of the same variety sown in different epochs were compared.

ISSN:0017-0070    

DOI:10.1080/11263506309430191

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Rate of plant development and endosperm texture inTRITICUM DURUMdesf. —The relationships between the rate of development of the plants obtained from kernels with hard or with porous endosperms have been examined. The devernalisation of the hard kernels obtained placing the kernels during 10 days at 25[ddot]C in moist air converts a hard endosperm into a porous one and the plants which grow afterwards have a lower rate of development than the controls.

ISSN:0017-0070    

DOI:10.1080/11263506309430192

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Formation and development of adventitious roots inOLEA EUROPAEAL.: Significance of the anatomical structure for the development of radicles. —A histological and anatomical study on olive-tree cuttings has been carried out in order to follow the structural modifications occurring during their stay in the rooting bed, and the processes of formation and development of adventitious roots. In the practice, the cuttings commonly used for the propagation of olive-tree are taken from 1-year old twigs; their rizogenous capacity is remarkably poor and the percentage of rooting may be increased only through special treatments (i. e. mist-propagation). The authors have studied the anatomical and histological causes of the different behaviour of coetaneous twigs taken from the same grown-up tree and kept under identical environment conditions. It has been ascertained the existence of a mechanical hindrance (the structure of the scleren-chymatous ring) to the development of the newborn radicles. When this hindrance is removed the newly formed radicles emerge along the internodes, and have no relation with the formation of a callus. To explain the different rhizogenous aptitude exhibited by the cuttings of the olive-tree a merely anatomical and histological study is not sufficient, but it is necessary to investigate also in the physiological field.

ISSN:0017-0070    

DOI:10.1080/11263506309430193

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263506309430194

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263506309430195

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0017-0070    

DOI:10.1080/11263506309430188

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor