44 



Garden and Forest. 



[January 23, 1889. 



Phalanopsis gloriosa. — This is one of the latest additions to 

 this beautiful genus. It is presumed to be a natural hybrid be- 

 tween P. amabilis and P. gra7idiflora, its habit and inflorescence 

 assuming- a character intermediate between these two species. 

 It appears to be a very robust grower, and excepting in this re- 

 spect it is by no means an improvement on either of its sup- 

 posed parents. But not so with the hybrids of P. Schilleria^ia 

 and P. a?nabilis, namely, P. casta and P. leiicorrhoda. These 

 are among the most beautiful of the whole genus, the former 

 having bronzy green leaves, while the latter has the marbled 

 leaves of P. Schilleriana. They vary little in tlie inflorescence, 

 the flowers resembling those of P. amabilis in form, being 

 pure white, with the base of the segments tinged witli rosy lilac, 

 and the lip beautifully speckled and marbled with purple. 

 Some fine examples of these are now in full beauty here, bear- 

 ing many flowered branching spikes. A rare variety of P. 

 leiicorrhoda (var. alba) is also in flower. This plant varies 

 from the type in the color of its flowers, which are almost 

 white. Another beautiful hybrid Phalaenopsis is P. intermedia 

 Brymeriajia. This is a rare kind, differing from the type in its 

 long, narrow leaves, which are pale green and speckled. The 

 flower spike is deep green and more in the way of P. rosea j 

 the flowers are white, suffused near the centre witli rose, while 

 the lip is a rich amethyst color. The handsomest and most 

 interesting hybrid at present in flower here is P. Harriettia, a 

 hybrid between P. amabilis and P. violacea, and previously 

 noted in these columns. This plant improves greatly in size 

 and color each year as it gets stronger. F. Goldring. 



Kenwood, N. Y. 



Zygopetalum Mackayi. — This is by no means a new or ex- 

 pensive plant, having been introduced from Brazil in 1825. I 

 consider it one of the very best amongst the autumn and winter 

 flowering Orchids. It grows and flowers profusely under 

 green-house treatment, not requiring as much heat as some of 

 the other species of this genus. If grown in .too warm a i&vc^- 

 perature the leaves are very liable to become spotted, which 

 detracts very much from the beauty of the plant. For florists' 

 purposes, like filling a large centre piece for table decoration, 

 three or four spikes of this plant in the centre with other 

 Orchids surrounding them would make a fine show. The 

 flower-stalk or raceme grows from one to two feet in height, 

 with large, purplish blue and white flowers, which emit a very 

 delicate fragrance. The culdvation of this Orchid is very sim- 

 ple, for it will grow equally well in either rough loam or peat- 

 soil if it only has good drainage. The pot should be about half 

 full of crocks to secure that result. It should have plenty of 

 water when in active growth, and even when dormant should 

 be kept moderately moist. Geo, Savage. 



Rochester, N. Y. 



Plant Notes. 



A 



The Banyan Tree. 



REPRESENTATION of one of the most remarkable 

 trees now known appears in our illustration upon page 

 43. It is the great Banyan tree in the Botanic Gardens upon 

 the banks of the Hoogly, below Calcutta, and the only survivor 

 of many hurricanes among the large trees which long made 

 this garden famous. It is believed to be only a few years more 

 than a century since the seed from which this tree sprang was 

 dropped by a passing bird into the crown of a wild Date Palm. 

 The main trunk is now, however, according to the latest sta- 

 tistics which have been published in regard to this tree, forty- 

 two feet in circumference ; there are two hundred and thirty- 

 two additional trunks, many of them eight or ten feet in 

 circumference, and the branches extend over an area eight 

 hundred and fifty feet in circumference, and form a dense 

 canopy of perpetual verdure, through which the sun never 

 penetrates. 



The Banyan {Ficus Indica), like many species of the genus, 

 springs from seed dropped upon the bark or in the crown of 

 some other tree. The young plant as it grows sends down its 

 roots, which finally reach the earth, and, increasing in vigor, 

 finish by strangling their host. These roots grow together and 

 form the nucleus of the main stem of the future giant. The 

 branches send down to the ground in turn roots which, in 

 time, become trunks, and so the tree goes on, spreading 

 farther and farther, until it may, in time, cover acres of ground 

 with its branches and afford shelter to thousands of men. 

 The famous Banyan upon the banks of the Nerbaddo, beneath 

 which Alexander the Great is said to have camped, once shel- 

 tered — if the story is a true one — 7,000 men; and in the present 

 century, although much reduced by the washingaway of some 

 of its trunks by floods, this tree has measured nearly 2,000 

 feet in (;ircumference and has had more than 3,000 stems. 



The tree in the Calcutta garden has been well cared for, and 

 every effort has been made to induce it to develop new trunks 

 to support the gigantic limbs which spread out horizontally 

 about ten feet from the ground, as appears from the following 

 extract from Hooker's "Himalayan Journals, "published in 1855, 

 in which a most interesting account of this tree may be found : 

 "The props are induced to sprout by wet clay and moss tied to 

 the branches, beneath which a little pot of water is hung, and 

 after they have made some progress they are inclosed in bam- 

 boo tubes, and so coaxed down to the ground. They are mere 

 slender whip-cords before reaching the earth, where they root, 

 remaining very lax for several months, but gradually, as they 

 grow and swell to the size of cables, they tighten, and eventu- 

 ally become very tense. This is a curious phenomenon, and so 

 rapid that it appears to be due to the rooting part dragging 

 down the aerial. The branch, meanwhile, continues to grow 

 outwards, and, being supplied by the new support, thickens 

 beyond it, whence the props always start outwards from the 

 ground towards the circumferance of the tree." 



The Banyan, as this particular species of the Fig is called, 

 although several others (including the Florida species figured 

 upon page 128 of our first volume) spread by supports developed 

 from aerial roots, has large coriaceous, dark green leaves, 

 five to six inches long by three or four inches broad, and 

 somewhat pubescent on both surfaces. The figs are the size 

 of cherries. 



Principles of Physiological Botany, as Applied to 



Horticulture and Forestry. 



IV. — The Destination of the Liquids Absorbed by Roots. — Evapo- 

 ration OF Water from Leaves. — Interruption of the Water 

 Current. — Extent of Root System. 



C OME very interesting facts appear when we compare the 

 •^ amount of roots in any given plant with the spread of 

 foliage. One of the earliest recorded comparisons is that of 

 Hales, in 1731, who gives the following figures in regard 

 to Sunflower, three and one-half feet high. There were 

 " eight main roots reaching fifteen inches deep, and sideways 

 from the stem ; it had, besides, a very thick bush of lateral 

 roots, which extended every way in a hemisphere about nine 

 inches from the stem and main roots." Adding together all 

 the different measurements, he foimd the roots were no less 

 than 1,448 feet in length, and the entire surface to be 2,286 

 square inches, or about sixteen square feet. The leaves of 

 the same plant measured 5,616 square inches, or about thirty- 

 nine square feet. 



Recent estimates give the following ratios of the parts 

 below ground to those above ground : 



Silver Fir, 169:100 



Norway Spruce, 267:100 



Scotch Pine, 477:100 



Hales' ratio would be for the Sunflower, . 41 : 100 



But from what was shown in the last paper, these figures 

 are very misleading, since they do not take into account the 

 surface of the root-hairs in the case of the Sunflower. In Abies 

 pectinata and some other Gymnosperms, no perfect root- 

 hairs are discoverable; the work of absorption is here* carried 

 on by the delicate cells just behind the tip, which are some- 

 times branched, but do not take on the regular forms of 

 ordinary root-hairs. When root-hairs are present in abund- 

 ance, as in the Sunflower and by far the greater number of 

 all our plants, the absorbing surface is surprisingly increased. 

 Estimates of the amount of increase can be only approxi- 

 mate, but the following are given by authors : In some 

 instances the surface is five times, and, in others, fifteen times 

 greater than without them. It should be borne in mind that 

 roots of some plants, especially trees, run through the ground 

 to very great distances, such as those commonly planted for 

 shade. 



The absorbing rootlets, with their zones of absorbing cells, 

 lie far away from the base of the trunk, and extend even 

 beyond the eaves of the canopy of foliage, where it would 

 seem as if the supply of water during a rain might be shed 

 rather more abundantly. In any event, the absurdity of water- 

 ing a shade tree near the trunk in time of drought is apparent. 

 The strong root-branches near the trunk are for mechanical 

 support, and take no part in the process of absorption from 

 the soil, except to transfer what the rootlets far remote from 

 them take in. 



The Path of Transfer. — The dilute aqueous solutions from 

 the soil absorbed by the rootlets are carried to the leaves. 



*There is possibly another mode in which these rootlets absorb nutriment from 

 the soil. This will be considered later. 



