1828 



TRAGOPOGON 



TRANSPLANTING 



A. Flowers purple 



porri!61ius, Linn. SALSIFY. VEGETABLE OYSTER. 

 OYSTER PLANT. Pigs. 2238, 2543. Tall strict biennial, 

 sometimes 4 ft. high when in bloom, glabrous: fis. 

 showy, closing at noon or before, the outer rays ex- 

 ceeded bv the involucre scales : peduncle thickened and 



2543. Flowers of Salsify or Oyster Plant 

 Tragopogon porrifolius (X %). 



hollow beneath the heads. S. Eu. Naturalized in many 

 parts of the country, often becoming a persistent weed. 

 See Salsify. 



AA. Flowers yellow. 



prat6nsis, Linn. GOAT'S BEARD. More or less branched, 

 3 ft. or less tall : outer rays exceeding the involucre 

 scales: peduncle scarcely swollen. A weed from Eu- 

 r pe- L. H. B. 



TRAILERS. See Vines. 

 TRAILING ARBUTUS. Epigcea, repens. 

 TRAILING BEGONIA. Cissus discolor. 

 TRAINING. See Priming. 



TRANSPIRATION is the process by which water is 

 given off in the form of vapor from leaves and stems. 

 Instead of a circulation of the sap in plants similar to 

 the movements of the blood of animals, water contain- 

 ing mineral salts is taken in at the roots in liquid form 

 and carried upward to the leaves through the woody 

 tissue, and then evaporated, leaving the mineral or ash 

 behind in the leaf, where it serves in making food. The 

 chief purpose of transpiration is, therefore, to carry a 

 stream of mineral food from the soil to the green parts 

 of the plant, although it also serves to aid in the ex- 

 change of gases with the air, and preserves more equable 

 temperatures of the body of the plant. 



Minerals may be absorbed by the plant only in very 

 dilute solutions. Hence it is necessary for the plant to 

 lift several thousand pounds of water to the leaves in 

 order to obtain one pound of minerals. After the mineral- 

 laden water reaches the green organs it is of no further 

 use and must be evaporated. It is estimated that 98 

 per cent of the energy received from sunlight by the 

 plant is used in this important work. That an enormous 

 amount of work is performed by the plant in transpira- 

 tion may be seen when it is known that a single sun- 

 flower plant will evaporate a pint of water from its 

 leaves in a single day, and about seventy times this 

 much in the course of its development. A birch tree 

 with 200,000 leaves will transpire from 700 to 1,000 



pounds of water daily in the summer. A single oak tree 

 will throw 120 or 130 tons of water into the air during 

 the course of a season, and an acre of beech trees con- 

 taining 400-600 specimens will transpire about 2,000,000 

 pounds in a single summer. 



To determine the exact amount of water transpired 

 by a plant, a specimen not more than a yard in height 

 growing in a pot may be used. Set the pot on a square 

 of oil-cloth, then bring the cloth up around the pot and 

 tie closely to the stem of the plant. This will prevent 

 evaporation except from the shoot. Now set the pre- 

 pared plant on one pan of a scale, together with a 

 small measuring glass, and balance. Allow the plant to 

 remain in the warm sunshine for eight hours, then 

 pour water into the measuring glass until the scale 

 shows original position or reading. The water in the 

 glass will represent the amount of transpiration. 



To demonstrate that water vapor does actually come 

 from the leaf, cut off a small leafy shoot of any conve- 

 nient plant and thrust the base of the stem through a 

 piece of cardboard into a tumbler of water; now cover 

 the exposed part of the shoot with another tumbler and 

 set in a warm, light place. Moisture, which could have 

 come only from the leaves, will soon gather on the glass. 



Some transpiration occurs over the entire surface of 

 the plant, although only about one-thirtieth as much is 

 given off by a stem as from the same amount of leaf 

 surface. The leaves are specially adapted to carry on 

 this function. The interior of the leaf is made up of a 

 great number of loosely arranged cells which evaporate 

 water into the air between them. The air in the leaf 

 communicates with the atmosphere through openings 

 called stomata, which are generally placed on the lower 

 side of the leaf. Consequently the watery vapor dif- 

 fuses put through the stomatal opening. The stomata 

 are controlled by guard-cells which may completely 

 close them up, and the action of the guard-cells is 

 under the control of the plant. When the plant is 

 losing too much water the stomata close; and they are 

 variously affected by winds and sunshine. 



Species growing in very dry localities adapt them- 

 selves to the conditions by building only limited sur- 

 faces from which transpiration may take place and by 

 reducing the number of stomata. The cactus is an ex- 

 ample of this type, and this plant transpires only about 

 one three-hundredth as much water as a leafy plant of 

 the same volume. As might be expected, the character 

 and amount of the mineral salts in the soil also affect 

 the amount of transpiration. j)_ ip < MACDOUGAL. 



TRANSPLANTING is a general term used to desig- 

 nate the removal of living plants whereby they may be- 

 come established in new quarters. Transplanting may 

 be performed when the plant is in a dormant condition, 

 as in winter, or when it is still actively growing. Small 

 herbaceous plants are usually the only ones that are 

 transplanted when in a growing condition, and this only 

 when the plants are living under special garden condi- 

 tions where they may have the best of attention as 

 to watering and shading. Considered from the stand- 

 point of the plant, transplanting is always a violent oper- 

 ation, for it destroys a considerable part of the root- 

 system, loosens the plant's attachment to the soil and 

 arrests for the time being a large part of its pro- 

 gressive vital activities. In order to overcome these 

 dangers the earth into which the plant is set should be 

 well prepared and moist, so that the plant may quickly 

 reestablish itself; part of the top usually should be re- 

 moved in order to lessen transpiration, and with succu- 

 lent and growing plants some shade should be pro- 

 vided for a time. The deeper and finer the soil, and 

 the greater the quantity of moisture it holds, the more 

 successful the transplanting operation will be, other 

 things being equal. The operation is also more 

 successful in humid regions, as in the Atlantic states, 

 than it is in dry regions, as on the plains and westward. 

 In the more arid parts of the country transplanting is 

 performed as little as possible, whereas in the eastern 

 part great quantities of annual and other garden plants 

 are transferred from seed-beds to the open ground. 



The successful transplanting of any plant depends in 

 part on the condition of the plant itself. The younger 

 the plant, as a rule, the better it withstands the opera- 



