Plant structure flower

The two types of wood differ, however, in their nature and structure. The main structural characteristic of the hardwoods (which are botanically known as angiosperms, plants that flower to pollinate for seed reproduction) is that in their trunks or branches, the volume of wood taken up by dead cells, varies greatly, although it makes up an average of about 50% of the total volume. In softwoods (from the botanical group gymnosperms, which do not have flowers but use cones for seed reproduction) the dead cells are much more elongated and fibrous than in hardwoods, and the volume taken up by dead cells may represent over 90% of the total volume of the wood. 

A compilation of structure-function relationships for plant cells is depicted in Table 2 while Table 3 categorizes their locations within plant tissues. A color atlas of plant structure has been published by Bowles (102). The reader is referred to Esau (103), Fahn (105), Fosket (108), Maseuth (106), Moore and Clark (109), Steeves and Sussex (104), and Raven et al. (107) for in-depth discussions of both the morphology and physiology of stems, roots, leaves, and flowers, i. e., plant organs. Certain of these volumes consider the structural differences between monocot and dicot roots and stems. 

Species of the mulberry family may be either monoecious or dioecious, depending on whether male and female flowers occur on the same plant (monoecious) or on separate plants (dioecious). Flowers of the Moraceae are in tightly packed groups, known as heads, spikes, catkins, or umbels. Fig flowers are produced inside a synconium, a hollow fleshy structure. The small flowers lack petals. Male flowers consist of four sepals, which are usually leaf-like appendages, and four stamens. Female flowers consist of four sepals and a pistil with a two-chambered ovary. 

Human interest in snowflakes has a long history. The oldest known recorded statement on snowflake forms dates back to the second century b.c. and comes from China according to Needham and Lu Gwei-Djen [2-26]. Flowers of plants and trees are generally five-pointed, but those of snow are always six-pointed . . . was stated as early as 135 b.c. Six was a symbolic number for water in many classical Chinese writings. The contrast between five-pointed plant structures and six-pointed snowflakes became a literary commonplace in subsequent centuries. Of several other relevant citations collected by Needham and Lu Gwei-Djen [2-26], another is reproduced here, from a statement by a physician from 1189 ... 

Fig. 2.36 The coffee shrub and its berries, cocoa beans and tea flowers. Shown below are the 3D molecular models of caffeine, theobromine and theophylline. The difference between the chemical structures is the number and position of methyl groups (highlighted by dark shacMng). (Authors own work and copyright-free pictures from the book Bessette, Alan E., Chapman, William K. (eds.) Plants and flowers. 1761 Illustrations for artists and designers. Dover Publications, Inc., New York, 1992)...

Pyrethrms are a group of naturally occurring insecticidal substances found in the flowers of vanous plants of the chrysanthemum family The following is the structure of a typical pyrethnn cmerin I (exclusive of stereochemistry)... 

Plant cells contain a unique family of organelles, the plastids, of which the chloroplast is the prominent example. Chloroplasts have a double membrane envelope, an inner volume called the stroma, and an internal membrane system rich in thylakoid membranes, which enclose a third compartment, the thylakoid lumen. Chloroplasts are significantly larger than mitochondria. Other plastids are found in specialized structures such as fruits, flower petals, and roots and have specialized roles. 

Abscisin II is a plant hormone which accelerates (in interaction with other factors) the abscission of young fruit of cotton. It can accelerate leaf senescence and abscission, inhibit flowering, and induce dormancy. It has no activity as an auxin or a gibberellin but counteracts the action of these hormones. Abscisin II was isolated from the acid fraction of an acetone extract by chromatographic procedures guided by an abscission bioassay. Its structure was determined from elemental analysis, mass spectrum, and infrared, ultraviolet, and nuclear magnetic resonance spectra. Comparisons of these with relevant spectra of isophorone and sorbic acid derivatives confirmed that abscisin II is 3-methyl-5-(1-hydroxy-4-oxo-2, 6, 6-trimethyl-2-cyclohexen-l-yl)-c s, trans-2, 4-pen-tadienoic acid. This carbon skeleton is shown to be unique among the known sesquiterpenes. 

The colors of flowering plants such as hydrangeas are highly sensitive to soil acidity. At pH > 6.5, these showy flowers are deep pink, but at pH < 5, the blossoms are vivid blue. The chemistry of these changes involves complexation of aluminum by pigments that have acidic groups, as the structures show. 

In addition to the bitter acids and essential oils, the flowers of hops offer a rich array of polyphenolic compounds, primarily chalcones and their accompanying flavanones, many of which are prenylated derivatives (Stevens et al., 1997,1999a, b). The most prominent flavonoid in all plants studied was xanthohumol [342] (3 -prenyl-6 -0-methylchalconaringenin chalconaringenin is 2, 4, 6, 4-tetrahydroxychalcone) (see Fig. 4.11 for structures 342-346). Several additional chalcones—variously adorned with 0-methyl and/or C-prenyl functions—were also encountered, along with their respective flavanones. Three new compounds were described in the Stevens et al. 

Many recent stndies of NMR spectroscopy have been reported for structure elucidation of anthocyanins from many plant materials such as carrot, tart berries, boysenberries, " flowers, black soybeans, and anthocyanin and flavonol derivatives in red wine. Ginsti et al. (1998) structurally elucidated two novel diacylated anthocyanins and two monoacylated anthocyanins from radish Raphanus sativus) by one- and two-dimensional NMR. Anderson et al. (2006) applied two-dimensional NMR to characterize carboxypyranoanthocyanins. Two 3-deoxyantho-cyanins, lnteolinidin-5-glncoside, and apigeninidin-5-glucoside were identified by Swinny et al. nsing H and C NMR. 

Carpita, N.C. and Gibeaut, D.M. (1993) Stmctural models of primary ceU walls in flowering plants consistency of molecular structure with the physical properties of the waUs during growth. Plant J. 3 1-30. 

The plant pigments responsible for the variable coloration in hydrangeas is the class of pigments known as the red and blue anthocyanins. The anthocyanins are water soluble and display a color dependent on the acidity of their environment in the flower petal vacuoles. In acidic solution, the general structure of an anthocyanin is given by Fig. 9.4.2, with a formal charge on one oxygen atom and... 

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