Inflorescence

Biology and Chemistry of Jerusalem Artichoke Helianthus tuberosus L. 

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The proportion of essential oil sensibly diminishes in the stems, in the leaves, and especially in the inflorescences, and in the whole plant. The most active formation of essential oil is, therefore, in the early part of the plant s life up to the commencement of flowering. 

September, 1905, the flowering completed. The percentage of essential oil in the roots has increased still further a slight increase has taken place in the stems no alteration is noticed in the leaves, and a diminution has taken place in the inflorescence. 

That distilled from young plants not exceeding 50 cm. in height, the inflorescence having formed, but the buds not having made their appearance. 

That distilled from the plant when the buds were commencing to appear, but from which the inflorescences were removed. 

After allowing for the relative weights of the leaves and inflorescences, the composition of the average oil which would have been yielded hy (2) and (3) if distilled together would have heen as follows —... 

If, on the other hand, the aldehydic or ketonic portion of the essential oil is sparingly soluble, the effects of the phenomenon of circulation on the composition of the essential oils from the various organs will be the reverse of those produced by the chemical changes which take place in the inflorescence, since the principles which are displaced are principally those which are most soluble. The relative insolubility of such ketones and aldehydes will tend to make the oil of the leaves richer in these compounds on account of their restricted power of circulation, and on the other hand, to make the oil of the inflorescences richer in alcoholic principles, whilst the actual formation of these compounds in the inflorescence will have the effect of increasing the proportion of aldehydes or ketones in the inflorescence. The net result depends on which of the two features predominates. 

The earlier researches of Charabot have shown that the essential oil of the flowers is richer in menthone than the essential oil of the leaves. And it is in spite of a circulation of menthol, a soluble principle, from the leaf to the inflorescence, that this latter organ contains an essential oil particularly rich in menthone. It must therefore be that the menthol is there converted into menthone by oxidation. 

The differences in composition between the two essential oils examined show well, if they be compared with those which exist between the essential oils of the leaves and the inflorescences, that the distribution of the odorous principles between the leaf, the organ of production, and the flower, the organ of consumption, tends to take place according to their relative solubilities. But this tendency may be inhibited, or on the other hand, it may be favoured by the chemical metamorphoses which the substances undergo at any particular point of their passage or at any particular centre of accumulation. Thus, in the present case, some of the least soluble principles, the esters of menthol, are most abundant in the oil of the leaves, whilst another, menthone, is richest in the oil of an organ to which there go, by circulation, nevertheless, the most soluble portions. This is because this organ (the flower) constitutes the. medium in which the formation of this insoluble principle is particularly active. 

A quite different approach to the study of plant responses to stress has been explored by those ecologists who have followed the example of Harper (1977) in applying to plants techniques originally deployed in investigations of animal populations. Here the methodology has been demographic and the resulting data have allowed responses to stress to be analysed in terms of fluctuations in the rates of mortality and recruitment of either plant populations or plant parts (e.g. leaves, inflorescences). 

Borokowski, B., Kowelewski, S. and Skrzypczakowa, L. 1966. Chemical composition of inflorescence of some Arnica spedes. 1. Analysis of flavonoid fractions. Ehss. Pharm. Pharmacol. 18 367-374. 

The leaves are simple, spiral and 4-7 cm X 5-8 mm. The blades of basal leaves are ellipticat and the cauline ones are linear-lanceolate. The inflorescence consists of numerous umbels spreading to form a large, loose panicle. The flowers are bright yellow. The achenes are oblong, brown, and prominently ribbed (Fig. 18). 

Carpesium divaricatum Sieb. et Zucc., or gankubisou (Japanese), is an herb that grows to a height of 1 m in shady and damp waste places, roadsides, and hillsides in China, Japan, and Korea. The leaves are lanceolate, and the inflorescences consist of yellow, cylindrical capitula (Fig. 25). 

LARKIN, J., Isolation of a cytochrome P450 homologue preferentially expressed in the developing inflorescences of Zea mays, Plant Mol. Biol., 1994, 25, 343-353. 

When the expression of CYP79B2 was driven by the 35S promoter, a 4-fold increase in indole glucosinolates was observed for approximately 20% of the transgenic lines, whose appearance also resembled that of wild-type plants.13 The majority (approximately 80%) of the 35S CYP79B2 lines exhibited dwarfism, did not develop inflorescences, and, therefore, did not produce seeds. A possible explanation for this phenotype could be that the LAOX produced by CYP79B2 was partly channeled into production of the plant hormone IAA, which would disturb the growth and development of the plants. 

The problem of classification is related to the occurrence of a large number of species wide spread throughout the world, mainly in the tropics, and to the difficulty of obtaining a quantity of plant parts of adequate quality sufficient for complete botanical investigation. In addition, some species exhibit local variation in some characters (leaf, inflorescence, flower), whereas others (fruit) remain constant. This led in the past and recent years to improper classification or to different and controversial classifications of the same plant. 

P. Lowalowski, J. Burczyk, B. Smietana, A. Stolarczyk, K.Terminska. M. Zych and M. Kopec, The optimization of the chromatographic separation of the inflorescences of Calendula officinalis (Asteraceae) — orange modification. Herba Polonica XLV (1999) 324—333 (in Polish). 

Jeng JH, Hahn U, Lin BR, Hsieh CC, Chan CP, Chang MC. (1999). Effects of areca nut, inflorescence piper betle extracts and arecoline on cytotoxicity, total and unscheduled DNA synthesis in cultured gingival keratinocytes. J Oral Pathol Med. 28(2) 64-71. 

More commonly, owing to continual grazing or mowing of the seedstalk before it reaches the inflorescence stage, turfgrasses grow asexually through... 

Craker, L. E., and W. A. Feder. Development of the inflorescence in petunia, geranium, and poinsettia under ozone stress. HortScience 7 59-60, 1972. 

Patterning of vegetation. Curtis and Cottam (18) observed the fairy-ring pattern of the prairie sunflower Helianthus rlgidus, which is due to a pronounced reduction in plant numbers, size, and inflorescences in the center of the clone. They subsequently demonstrated that the pattern was due to autotoxins produced by decay of dead parts of the sunflower. 

Figure 4. Artemisia herba-alba, Branch (a) and Inflorescences (b). ...

Broccoli production. Table II shows results for the different treatments tested in summer 1983. All the parameters (mean number of har-vestable heads, mean diameter of the inflorescence, and total biomass produced) indicate that growth of broccoli was stimulated by cam-pestris. 

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