42 



Garden and Forest. 



[January 22, 1890. 



habit is good and often exceedingly graceful ; the foliage 

 has a bright cheerful green color, and the leaves remain 

 fresh and green on the branches long after those of nearly 

 all our other native trees have fallen. They drop finally 

 without any marked change of color. This tree grows 

 very rapidly ; it is free from serious attacks of insects, and 

 it is admirably suited to plant as a street or roadside tree. 

 It will thrive in all sorts of soil and in all exposures, still 

 there are few American trees which have been so seldom 

 planted, or whose beauty or value are so little known or 

 appreciated. 



The illustration on page 43 is from a photograph for 

 which we are indebted to Dr. William Herbert Rollins, of 

 Boston. The illustration serves to emphasize what has 

 been said more than once in these columns, that trees in 

 winter possess peculiar beauty, and that to know them well 

 and to appreciate them they must be seen at this season of 

 the year as well as in the summer. C. S. S. 



Foreign Correspondence. 



London Letter 



The Weather Plant. — About a year ago we were informed 

 by the London papers that Mr. Nowack, of Vienna, had dis- 

 covered a wonderful property in the leaves of the plant whose 

 seeds are commonly known as "Crab's-eyes," and which is 

 known by the name of Abrns precatorius. Like a great many 

 plants belonging to LeguminoscE, the leaves of the Abrus per- 

 form many extraordinary movements under the influence of 

 light, etc. Whatever the cause may be, no one can doubt that 

 the movements of the leaves of this plant, of the Sensitive 

 Plant (Mimosa), of the Telegraph Plant (Desmodium), of many 

 Acacias, Bauhinias, and other Legumes, have not yet been 

 properly accounted for. Charles Darwin made many experi- 

 ments and observations on these very movements, and finally 

 concluded that "leaves which sleep continue to move during 

 the whole twenty-four hours." He also demonstrated that 

 there is a continual motion going on, although not generally 

 perceptible, in all plants at all times. The Abrus is not the 

 most striking amongst plants whose movements are excep- 

 tionally palpable; but Mr. Nowack, ■ after long observation, 

 concluded that in them we possess a " weather indicator" 

 much more trustworthy than any meteorological instrument 

 whatever. He declares that "its sensitiveness to atmospheric 

 and electric influences may be turned to practical account for 

 forecasting the local weather, with truly marvelous precision, 

 forty-eight hours beforehand, and likewise earthquakes or 

 subterraneous disturbances, both at a distance and locally, 

 with respectively three to eight days previous notice." An 

 apparatus in which the plants were to be grown was patented 

 by Mr. Nowack, and this, along with his plants, he brought to 

 Kew in July last, with a letter of introduction from H. R. H. 

 the Prince of Wales. 



The Directors of Kew naturally afforded every facility to 

 Mr. Nowack in his demonstrations, and Dr. Oliver, one of the 

 best of the younger school of physiological botanists, under- 

 took to watch and check Mr. Nowack's work. The result is 

 about to be published in the Kew Bulletin. That the plant is 

 of absolutely no value as a weather indicator is proved by the 

 statistics given in Dr. Oliver's report. Mr. Nowack's prognos- 

 tications were scarcely ever nearly right, and whatever the 

 cause of the movements it is proved that they are not pro- 

 duced by the weather of the day after to-morrow. Mr. Nowack 

 may plead that weather in England is made up of samples, 

 and no plant, nor yet instrument, however nicely arranged, 

 could foretell weather here. The movements of the leaves of 

 the Abrus are influenced by changes in the intensity of light, 

 changes in atmospheric humidity, and changes in temperature. 

 So also are the movements of many other Leguminous plants; 

 but why their leaves should move so conspicuously whilst 

 those of other plants under the same conditions show no per- 

 ceptible movement remains an unsolved problem. 



The idea that some plants in their movements foretell the 

 weather is not new. At the end of last century, Ruiz and Pavon 

 describe the movements of Porlieria hygrometrica, a Chilian 

 Zygophyllaceous plant, not unlike a Mimosa. These move- 

 ments, they say, foretell the weather by closing their leaves in 

 the evening half an hour before sunset if the morrow is to be 

 dry, and an hour before sunset if it is to be overcast and tem- 

 pestuous. This plant is in cultivation at Kew, and Dr. Oliver 

 has found nothing in its movements^to support the above theory. 



A Gardener's Problem. — Under this title the Director of 

 Kew has communicated to Gardeners' Chronicle, a paper on 

 horticulture, which he declares is "essentially an empirical 

 art." This statement the editor of that journal finds fault with 

 on the ground that it is too absolute, and " very discouraging 

 to those who believe that practical horticulture has a right to 

 look to vegetable physiology and anatomy for guidance and 

 profitable suggestion, and, moreover, that it will not look in 

 vain." I need not attempt to reproduce Mr. Dyer's arguments 

 here; but I may say that, however discouraging it may appear, 

 there is no getting away from the fact that horticulture, pure 

 and simple, high-class horticulture, too, obtains practically 

 very little help from the professors of physiology or any 

 other department of botany. An exception might be allowed 

 in favor of those who supply names for garden plants, but 

 the name of a plant is of no assistance in its cultivation, and 

 there are dozens of first class cultivators whose knowledge 

 of nomenclature would be called wofully deficient by the 

 systematic botanist. On the other hand, there are many good 

 gardeners who know a good deal of botany ; but they are no 

 better cultivators on that account. I use the term gardener 

 only in the sense of a cultivator of plants. The gardener as 

 an educated man is another question. It would not be difficult 

 to name a dozen men, past and present, who stood, or stand, 

 head and shoulders above their compeers in a knowledge of 

 gardening art, but who never looked for any assistance from 

 the physiologist, and probably never wanted it. The fact is, 

 as Mr. Dyer states, good gardening is the outcome of experi- 

 ment, and he is the most successful cultivator who is the most 

 thoroughly acquainted with the best methods — i. e., the best 

 results arrived at by experiment on the part of gardeners 

 generally. Take as an example any plant newly introduced, 

 whose cultural requirements are unknown. Nepenthes 

 Rajah was introduced by Messrs. Veitch about six years ago. 

 They knew where it came from, and no doubt were well ac- 

 quainted with the conditions under which it grew when wild.* 

 The plants of N. Rajah were distributed, and many were lost 

 through wrong treatment, even by those who grow Nepenthes 

 well. It looked as if this grand Pitcher Plant would prove in- 

 capable of cultivation, when lo, the information came from 

 Glasnevin, the garden of many important horticultural achieve- 

 ments, that the cool conditions afforded by the Masdevallia, 

 house suited exactly this Nepenthes. Physiology would not 

 have been of the slightest avail if called in here, nor would 

 anything have equaled the empirical act of Mr. Moore when 

 he removed a Nepenthes from the hottest to the coldest house 

 and watched the result. It often proves the case that some 

 outsider, working in utter ignorance of the conditions pro- 

 vided by Nature for a particular plant, has discovered the best 

 method of culture by accident, some would say, but at any 

 rate, by purely empirical means. Propagation, one of the most 

 important departments of horticulture, neither seeks nor re- 

 quires assistance from the botanist, and it is questionable if the 

 botanist could help toward the discovery of the most suitable 

 method for the multiplication of any plants. So far as I know 

 he has not done so yet. ' 



Botany, however, explains a great deal of what the gardener 

 does, and in this manner it may be said to help him. The 

 man who understands somewhat the nature of what he is 

 doing is superior to the man who works blindly by rule of 

 thumb. The fact remains, however, that horticulture goes its 

 own way, and by experimenting in all directions discovers the 

 needs of most plants in a manner that often astonishes the 

 botanist. It may be heresy to say so, but the scientific man 

 who knows nothing of horticultural art, is oftener a hindrance 

 than a help to the gardener; and it is not until he has tried to 

 grow plants by the light of his science, and not according to 

 the rules of horticulture, that he discovers with Professor For- 

 ster "that there are more things in the plant and in the soil 

 than are dreamt of in the latest philosophy of our newest 

 botany," and the gardener who aims only at fitting the plant 

 and the conditions at his command, so as to make them agree, 

 obtains better results than could be got by the most minute 

 research in the botanical laboratory. 



This subject leads one to the consideration of horticultural 

 schools, which are occasionally recommended as affording 

 that kind of training most desirable in a gardener. During 

 the last ten years I have been brought into contact with some 



* Mr. Burbidge, who found this plant in Borneo, thus writes of it in his charming 

 book, "The Gardens of the Sun," p. 100: "On open spaces among rocks and 

 sedges the giant Nepenthes Rajah began to appear, the plants being of all sizes 

 and in the most luxuriant health and beauty. The soil in which thev grew was a 

 stiff yellow loam, surfaced with sandstone grit, and around the larger plants a good 

 deal ofrich humus and leaf debris had collected." Still higher up the same mountain 

 Mr. Burbidge found iV. villosa, and it is remarkable, that whilst the latter thrives 

 only in the hottest and moistest stove. A''. Rajah must be treated as a cool plant. 

 Who would think of attempting to grow Nepenthes in a " stiff yellow loam ? " 



