Vegetative stem

Tough plant and vegetable stems Old bedding plants Fall leaves ... 

Bauer and Remiger (1989) reported that the tetraenoic alkamides content was 0.04-0.39 mg/g root of E. purpurea and 0.09-1.51 mg/g root of E. angustifolia. The aerial parts had less than 0.01-0.3 mg/g of these alkamides in samples obtained from the United States and Europe. Rogers et al. (1998) found similar levels of tetraenoic alkamides in Australian-grown E. purpurea and E. angustifolia. Perry et al. (1997) observed that the tetraenoic alkamides accounted for 27% of the alkamides in the roots, 71% in the rhizome and 74% in the vegetative stem. These three parts are often harvested as a root and thus collectively the root system accounted for 84% of the total tetraenoic alkamides in the E. purpurea plant tissue. In the aerial parts of the plant, 64% of tetraenoic alkamides were found in the flower, and 31 and 5% were found in the reproductive stem and leaves, respectively. In E. purpurea, the tetraenoic alkamides accounted for 45 and 76% of the alkamides from the roots and aerial parts, respectively (Wills and Stuart, 1999). Additional research showed that the tetraenoic alkamides dodeca-2 , 4E, 8Z, lOZ-tetraenoic acid isobutylamide and... 

Location Roots Rhizome Flower Leaf Vegetative Stem Productive Stem... 

The vegetative stem. This does not produce a flower, and has not such an erect habit of growth as the culm. Perennial grasses have both flowering and vegetative stems. 

Polysaccharides are macromolecules which make up a large part of the bulk of the vegetable kingdom. Cellulose and starch are, respectively, the first and second most abundant organic compounds in plants. The former is present in leaves and grasses the latter in fruits, stems, and roots. Because of their abundance in nature and because of contemporary interest in renewable resources, there is a great deal of interest in these compounds. Both cellulose and starch are hydrolyzed by acids to D-glucose, the repeat unit in both polymer chains. 

Vegetable fibers are classified according to their source ia plants as follows (/) the bast or stem fibers, which form the fibrous bundles ia the inner bark (phloem or bast) of the plant stems, are often referred to as soft fibers for textile use (2) the leaf fibers, which mn lengthwise through the leaves of monocotyledonous plants, are also referred to as hard fibers and (J) the seed-hair fibers, the source of cotton (qv), are the most important vegetable fiber. There are over 250,000 species of higher plants however, only a very limited number of species have been exploited for commercial uses (less than 0.1%). The commercially important fibers are given ia Table 1 (1,2). 

Urena and Abutilon. These are less important vegetable fibers of a jute-like nature. Urena lobata (Cadillo) of the mallow family (Malvaceae) is a perennial that grows in Zaire and Brazil to a height of 4—5 m with stems 10—18 mm in diameter. Because of a lignified base, the stems are cut 20 cm above the ground. The plants are defoflated in the field and retted similarly to jute and kenaf. The retted material is stripped and washed and, in some cases. 

Castor oil is also known as riciaus oil, oil of Palma Christi, tangantangan oil, and neoloid. Typical of vegetable oils and most fats, castor oil is a triglyceride of various fatty acids (see Fats and fatty acids.) Its uniqueness stems from the very high (87—90 wt %) content of riciaoleic acid, stmcturaHy... 

It is important to note that diet is a complex mixture that contain compounds with varying activity. Chemical stimulators of colon cancer growth include bile acids, 1,2-diglycerides and prostaglandins which stem from consumption of fat. In contrast, fruits and vegetables contain substances such as carotenoids, flavonoids and fibre, which may inhibit cancer cell growth, and the risk of colon cancer appears to be mirrored by the ratio of plant sterols to cholesterol in the... 

Quantities of nutrients lost will also be dependent upon the type of vegetative materials harvested. Tissue nutrient concentrations are highest in fine wood debris (stems and twigs), leaves and reproductive plant parts. For example. 

Only natural dyes were known until the nineteenth century. By trial and error and probably also by chance, humans learned to extract and use a large variety of dyes of vegetable and animal origin. Dyes were extracted from the roots, trunk bark, and branches of trees, the stems, leaves, flowers, and fruits of plants, the bodies of insects and mollusks, and the eggs of insects. All the dyes obtained from natural sources are rather impure, and hence the accurate reproducibility of colors was almost impossible during antiquity. Still, many of the dyes and dyeing techniques used in antiquity were highly developed and remained in use until the discovery of the synthetic dyes in the middle of the nineteenth century (Colombo 1995 Robinson 1969). 

---