1146 



ESCONTRIA 



ESCONTRIA (named for Sefior Don Bias Escontria, 

 of Mexico). Cactacese. Large, much-branched cacti. 

 Ribs few: areoles narrow, bearing pectinate clusters 

 of spines: fls. small, yellow, diurnal: fr. and ovary 

 covered with chartaceous, translucent, persistent 

 scales, without hairs or spines; fr. fleshy, edible; seeds 

 black. For cult., see Succulents. 



chiotilla, Rose (Cereus chiotilla, Web.). Sixteen ft. 

 or more high: ribs mostly 7: radial spines 10-15; cen- 

 tral 1-2, the upper one 2 in. long, curved downward: 

 fr. 1 in. diam. Mex. Rare in cult. j. N. ROSE. 



ESPALIER, a trellis or open support on which a 

 tree or woody plant is trained in formal shape and to a 

 given number of branches, usually in a vertical plane; 

 and also the plant so trained. Apple trees and others 

 are often trained as espaliers in Europe; the tree may 

 be transplanted and subsequently attached against a 

 wall or building, or it may be kept permanently on the 

 trellis or open support. Sometimes espalier-training is 

 employed only when the tree or bush is young, for the 

 purpose of bringing it into shape and to prepare it for 

 a wall or other support. Trees are trained on espaliers 

 also to give them full exposure to the sun on all sides, 

 to regulate the fruit-bearing and to provide easy means 

 of controlling insects and diseases. Espalier-training is 

 most frequent in cool and cloudy regions, in those in 

 which space must be utilized to the utmost, and where 

 hand-skill is obtainable or is relatively cheap. 



There are many forms of training. The plant may 

 be trained to a single shoot, or to two shoots lying in 

 opposite directions, mostly horizontal, in which case 

 it is called a cordon; or the top may be spread fan- 

 shaped on the trellis, or in other forms, and it may 

 then be called an espalier. The training is begun 

 when the plant is very young perhaps only a year 

 or two from the graft or bud and before it has pro- 

 duced a stiff trunk and unmanageable head. Usually 

 the branching is started within a foot or so of the 

 ground by heading back the main stem; and as many 

 shoots as may be desired on the trellis are allowed to 

 grow. These shoots are tied to the trellis or posts as 

 they grow, and the side shoots are pinched out except 

 such as are desired for further arms in the framework 

 or for fruit-spurs. The trellises themselves may be of 

 wire strung on posts, or the tree may be tied from 

 post to post or stake to stake set close together. Espa- 

 liers are little used in this country, and then only in 

 small gardens, and mostly when a trained gardener is 

 employed. L. H. B. 



ESULA: Euphorbia. The E. cristata of the trade is probably 

 the cristate form of Euphorbia lactea or similar species. 



ETHERIZATION OF PLANTS. Etherization, as 

 applied to plants, means strictly the forcing of a dor- 

 mant plant into growth by subjecting the plant to ether 

 vapors at certain concentrations in a closed chamber 

 for a definite period of time, usually twenty-four to 

 seventy-two hours. The plant after such treatment is 

 placed under environmental conditions favorable for 

 growth. Since in practice the use of chloroform is 

 similar in its application and effects, it will be discussed 

 here. The general nature of etherization was first 

 noted by Johannsen in 1890, and following his investi- 

 gation a wide stimulus was given to the commercial 

 forcing of flowering shrubs. For other methods of 

 forcing a dormant plant, see Rest-period. 



Before discussing the method of etherization, its 

 effects and application, it is necessary first to have some 

 idea of what is meant by the term rest-period or the 

 condition of dormancy. 



Rest-period. 



Perennial plants, especially those in the temperate 

 regions, in general have a season of growth and active 

 metabolism followed by a period of quiescence as 



regards any outward manifestations of metabolism. 

 During this period, not all of the vital processes are at 

 a standstill and changes in the reserve food may be in 

 progress, but the plant appears to be at rest and is 

 dormant. The rest-period begins with the advent of 

 the unfavorable growth conditions of the autumn, and 

 normally continues until the favorable conditions of 

 the spring. 



One might reasonably assume that growing perennial 

 plants removed from out-of-doors at the approach of 

 autumn conditions to a greenhouse, would continue 

 growth and not pass into the rest condition. One might 

 assume, also, that if a plant in a dormant condition be 

 brought into favorable conditions it would resume 

 growth immediately. But experience and investiga- 

 tions show that many plants will not immediately con- 

 tinue growth, and, provided they do continue growth, 

 it is at a slower rate. Dormant plants, that is those in 

 the rest-period, may require considerable time before 

 resuming growth. There are some plants that during 

 dormancy respond quickly when brought into the 

 greenhouse; there are others that remain dormant 

 despite the most favorable environmental conditions. 

 The rest-period in various species of Acer (maple), of 

 Quercus (oak), of Fraxinus (ash), and of Fagus sylvat- 

 ica, as well as other plants, is so well fixed as to make 

 it almost impossible to force the dormant plants into 

 growth by warmth and moisture alone. Special treat- 

 ment is necessary, such as etherization. There are 

 other plants in which the rest-period is not well estab- 

 lished. These quickly respond to favorable growth con- 

 ditions normally prevailing in a greenhouse. In many 

 plants this rest-period has attained an almost habit- 

 like character. The following table with data taken 

 from results secured by Howard with branches 

 brought into the greenhouse at Halle, Germany, is 

 instructive: 



GROWTH RESPONSE OF BRANCHES WHEN BROUGHT 

 INTO GREENHOUSE. 



*0=No growth 



In the investigation made by Howard, 234 species 

 were collected from October 20 to November 4, and of 

 these only 125 grew; and of the 125, only 18 per cent 

 began growth within a period of nine days. Between 

 January 8 to 10, another collection was made includ- 

 ing practically all the species of the first lot and others 

 in addition, so that the number totaled 283 species. 

 Of this number 244 grew, of which 50 per cent began 

 growth within the first nine days. The species that 

 did not grow when brought into the greenhouse Janu- 

 ary 8 to 10 made growth when brought into the green- 

 house on February 26. From these and the results of 

 other experiments the conclusion is drawn that plants 

 in general tend to pass out of the rest condition as the 



