VARIEGATION 



vigor of the plants are reduced as a result. It is further 

 tvident that the initial causes of variegation may In 1 

 quite diverse, some of the most usual being seed of 

 low vitality ; unsuitable nourishment, especially a lack 

 of elaborated nitrogen ; rapid growth in very moist 

 soil : severe injury to the roots during a period of rapid 

 growth of the upper parts of the plant; severe cutting 

 back, etc. 



Though started at first through the influence of envi- 

 ronment, variegation, when of value horticulturally, 

 lias in many cases been increased and fixed by selection 

 till it has become almost a specific character in some 

 groups of plants. 



Ant nut mil t'i>lor<tti<i,A word might be said in this 

 connection regarding autumnal coloration. The produc- 

 tion of color in autumn foliage is, as is well known, due 

 in part to the gradual destruction of the chlorophyll 

 when the leaves have reached maturity and approach 

 the period of death, and in part to the action of acids 

 on anthocyanin as described below. Many of the de- 

 structive changes which take place in the chlorophyll 

 are oxidation processes, the same as occur in the 

 cells of highly colored variegated plants, and physio- 

 logically they are not very different from the changes 

 occurring in Calathea, Caladium, Codiaeum, etc. The 

 approach of maturity in the leaf, and the coming on 

 of cool weather in autumn, stimulates the production of 

 oxidizing ferments, and the action of these and the 

 acids of the cell-sap upon the chromogen, or color con- 

 tents of the leaves, especially the chlorophyll and 

 anrhoeyanin, causes many of the brilliant colors of 

 autumn foliage. There is a popular belief that these 

 colors are due to cold weather or frosts; but while 

 frosts, if they are light, hasten the solution and de- 

 struction of the chlorophyll, they cannot be looked upon 

 as more than hastening "changes which would occur in 

 time without them. Even in the tropics, some foliage 

 before it matures becomes highly colored, and on the 

 Japanese maples the writer has observed beautiful 

 autumnal colorations in July in the region of Washing- 

 ton. 



In practically all deciduous trees, bushes, etc., before 

 the maturing and falling of the leaves, all of the valu- 

 able food materials, such as sugars, albuminoids, etc., 

 pass from the leaves through the vascular bundles into 

 the twigs and branches so that they are not lost to the 

 plant. When the leaves finally fall they are therefore 

 nothing but mere skeletons, containing waste materials. 

 In the passage, especially of albuminoid matters, from 

 the leaves to the stems, it is necessary that the ma- 

 terials be protected from the strong action of light, and 

 it is believed that part of the coloration of maturing 

 leaves serves this purpose. 



A coloring material, or chromogen, known as anthocy- 

 anin, is always present in such cases, and develops 

 beautiful reds when the cell-sap is acid, blue when no 

 acids are present, and violet when there is only slight 

 acidity. This, in connection with the disorganizing 

 chlorophyll, causes the various mixtures of yellow, 

 brown, violet, red, orange, etc., of autumnal coloration 

 as described above. In very young leaves of many 

 plants, such as Ailanthus gland it lx<i, Jiiylans regia, 

 Vitis, Cissus, and many other plants, this same antho- 

 cyanin is developed as a protection to the albuminoid 

 materials traveling to the young cells. Such protective 

 colorations have to be distinctly separated from varie- 

 gations. In evergreen leaves, during the winter, the 

 chlorophyll granules are protected by the development 

 of anthocyanin, forming a brownish or reddish tinge in 

 the cell-sap. This is especially prominent in many 

 conifers. 



While, as stated above, these protective and in some 

 cases transitory colorations should be, clearly distin- 

 guished from variegation, it is an interesting fact that 

 they develop when the conditions for active nutrition are 

 unfavorable, and may in many cases be produced in 

 maturing leaves by starving the plants or permitting 

 them to become sufficiently dry to check growth. 



CWorrt.si.s.-This term is usually applied to those 

 cases of the production of yellow or white foliage caused 

 by a lack of some nutrient salt, such as iron, potash, 

 lime, phosphoric acid, etc. The most common cause of 

 chlorosis, or yellowing, is due to the lack of iron. In 



120 





1903 



such cases, the disease j s readily cured by cither -pray- 

 ing the foliage with a dilute omtton of iron sulfate or 

 other iron .suit, or watering the roots with the MUIIC. 

 Hven within a few hours the chromoplasts will betrin to 

 turn green, and the plant goes on making' staid, und 

 sugar from the carbon dioxid of the air in the normal 

 manner. A lack of phosphoric acid sometimes cm. 

 similar trouble, which is cured by the addition of this 

 nutrient substance to the soil. Numerous cases are on 

 record of yellowing of foliage due to excess of soluble 

 lime in the soil. Grapes are especially sensitive to an 

 excessive amount of lime, ami turn yellow readily as a 

 result of its action. Soils which contain too much mag- 

 nesia in proportion to lime also often cause a yellowing 

 of foliage of plants growing in them. All causes of this 

 kind can be readily distinguished from variegation by 

 the fact that all the young leaves produced under such 

 conditions become yellowish or white and are not mot- 

 tled or marked as in variegated plants. Moreover, the 

 condition is readily corrected by furnishing the proper 

 nutrition, and usually all plants growing in such soils 

 show the same trouble. ALBERT F. WOODS. 



VARNISH TREE. KceJreuteria paniculata, Ailini- 

 (Jiiifi i/liiHtltilii.'ni. JfJinx vernicifera, and other plants. 



VASES. Such vases as are shown in Fig. 2642 are 

 common features of formal gardening. All matters 

 concerning their manufacture or beauty are clearly 

 outside the province of this work, but every gardener 

 who purchases such a vase is interested in certain 

 practical horticultural features of its construction. It 

 is imperative that the vase have a hole at the bottom 

 for drainage, otherwise the soil will become sour. It 

 is desirable that the rim of a vase be rounded, as a 

 sharp edge cuts the vines that trail over it and are 

 swayed by the passing 

 wind. Many of the 

 old-fashioned stone 

 vases 4 or 5 ft. high 

 were made with a bowl 

 too shallow for the 

 good of the plants. 



Vases are generally 

 stationed in conspic- 

 uous positions near 

 buildings, where they 

 receive daily attention 

 from all, including the 

 gardener. It is neces- 

 sary to water them 

 every morning during 

 hot weather, and it is 

 therefore desirable to 

 have the water supply 

 near at hand. A water- 

 ing cart is often used 

 in taking care of vases. 

 Vases are often placed 

 in the sunniest situa- 

 tions, but they can also 

 be used in partially 

 shaded spots. On the 

 north side of a build- 

 ing in a shady place 

 sheltered from the 

 high winds small palms 

 may be used in vases, 

 together with Rex be- 

 gonias and Pandanux 

 Veitchii. 



The plants used in vases should be or a Or tr,-, 



and resistant to drought, dust and occasional high 

 winds, ('annas, ferns and foliage plants that are likely 

 to be cut or whipped by the winds are necessarily ex 

 eluded. The first thought should be given to a center- 

 piece This should usually be some plant of a rather 

 stiff formal or architectural nature. Cnnli/lnte indiv 

 and C. <i,,st,;,li* are excellent for the pur: 

 should stand well above the other plants. Around the 

 edge* vines are OMd, e-pccially periwinkles, green 

 and variegated, nasturtiums and S,>n,-,,, nnkunioides. 

 Another choice plant for this purpose is Heltckrywm 



2642. Stone flower vase 4 or 5 

 feet high, used in formal gar- 

 dening. 



