90 



JOTJENAIi OF HOETICULTUEE AND COTTAGE GARDENER. 



[ Au^Bt 4, IS63. 



This mode of proceeding will be likely to remedy the evil 

 if it arises from the causes named, and is very commonly 

 resorted to when the plants show signs of running to leaves 

 and young shoots instead of being as fruitful as is desired ; 

 and as far as our own practice is concerned the pinching 

 and disleafing has always proved successful when there was 

 a disposition to ban-enness. 



The Tomato, as most gardeners are aware, can be most 

 successfully cultivated under glass, and is generally resorted 

 to in localities where the climate wiU not ripen the fruit 

 when trained to a south wall. It is a good plan to let them 

 attain a considerable size in pots before planting them out. 

 Theii- being somewhat potbound for some time of course 

 throws them into a fruiting condition, and there is little 



fear of their becoming too stunted after being planted out. 

 Such is not theii- ten dency at aU, but the very reverse. 



For the production of Tomatoes early in the season there 

 is perhaps no better way than that of growing and fi'uiting 

 them in pots, unless, perhaps, where they can be planted 

 out and kept warm all winter : then they become almost 

 perpetual in bearing. When grown in pots seed should be. 

 sown in autumn, and they can be wintered in a cool di-y 

 stove, and shifted on in spring into 10 or 12-inch jjots. 

 They ripen their crop early in summer ; but under all these 



; circumstances it is necessary that they should be well, 

 pinched back as they make growth, and that they be kept 

 thin of leaf, so that the blooms be not smothered-ui). — 



I D. Thomson, Archerjield Ganlem. 



COLOCASIA ODOEATA. 



The fragi'ance of this species renders it a desu'able subject 

 in aU collections of stove jjlants. The diffused odom', as it 

 pervades the entii-e atmosphere of a hothouse in which the 

 plant is blooming, resembles that of Mignonette ; but the 

 more powerful and concentrated fragi-ance which is ex- 

 perienced on nearer contact with the plant, is of the sweet 

 aromatic natm-e of that of some Orchids. The Colocasia 

 odorata is not a novel plant, but it is not common. It is 

 one of the arborescent ai-oideous plants, which give such a 

 tropical air to collections in which they occur. This species 

 gi'Ows with a caudex of 3 to 6 feet high, and from 4 to 

 6 inches in diameter, and is then crowned at the top with a 

 head of lai-ge, narrowly cordate leaves, supported on long 

 stout footstalks, and traversed by prominent veins. The 

 flowers grow from the 

 axils of the leaves to- 

 wards the centre of 

 the plant, and stand 

 erect among the fo- 

 liage. The spathe is 

 about a span long, 

 contracted below the 

 middle, and then ex- 

 panding into a con- 

 cave or boat-shaped 

 membrane, which at 

 first stands erect, en- 

 cu'cling the spadix, but 

 ultimately bends over 

 it like a hood. The 

 spathe is green at fii-st, 

 but acquires a yellow- 

 ish hue when at ma- 

 turity. The spadix 

 is club - shaped, and 

 shorter than the 

 spathe. 



The foliage of the 

 Colocasia is the seat 

 of a waxy secretion, 

 which, though scanty 

 in the plants cultivat- 

 ed in our hothouses, is 

 yet produced in con- 

 siderable quantities when the plant is gi-owing in its 

 natural climate. The secretion is formed exclusively on 

 the lower face of the leaves, and is confined to the axils 

 of the principal nerves, where the cellular tissue produces it, 

 and from wliich points this waxy substance extends some- 

 times over nearly the whole inferior surface of the foliage. 

 In the cultivated plant it only exists in small scales, at the 

 utmost not larger than the human nail. 



A curious property possessed by the plants of this family, 

 is the evolution of heat at certain periods of their inflores- 

 cence. This has been noticed by various observers, but ap- 

 parently first by Lamarck, who, in 1777, made the discovery 

 upon Arum italicuni. The most exact experiments, how- 

 ever, are those of M. Adolphe Brogniart, made in 1834, upon 

 a plant of the Colocasia odorata, which developed four 

 flowers in the space of a month. 



" The fii'st flower began to expand on the 4th of March ; 

 but it was not tUl the 6th that the escape of pollen from its 

 anthers commenced, and the increase of temperature on the 

 spadix was perceptible to the touch. A very smiiU ther- 

 mometer, when apphed to the flower, indicated a tempera- 

 ture in the ah' of 23° centigrade, while tiie spadix close to 

 the fertile stamens, was 20°, and the club formed by the. 

 abortive stamens was 30°, the difference being 7°. The heat 

 of the flower gradually duuinished, and, in the evening, its 

 temperatiu-e was the same as that of the stove. It is re- 

 markable, however, that, while all the other Aroideoe that 

 have been examined on this point, appear — when the heat 

 has once ilisappeared, — never to regain it, the pl.ant under 

 consideration exhibited the same increase of temperature at 



the same hour (2 p.m.) 

 of the following day, 

 and for four days it 

 continued, althougli 

 with gradually dimi- 

 nishing intensity, to 

 present a similar phe- 

 nomenon, when the 

 flower finally faded. 



" Another blossom 

 having appeared 

 shortly after, I adopt- 

 ed many precautions 

 which should enable 

 me to watch its pro- 

 gi'ess. I procured a 

 very delicate thermo- 

 meter, apjjlied it ac- 

 curately to the most 

 sensible parts of the 

 flower; and protected 

 the bulb by folds of 

 flannel from the in- 

 fluence of the circum- 

 ambient atmosphere, 

 and by a pui-ple shade 

 &-om the rays of the 

 sun. Another thermo- 

 meter was susijended 

 in the stove, not far 

 from the plant, to give the temperature of the stove. For 

 six days a striking increase of heat took place in the flower, 

 attaining its maximum about 4 p.m., and totally ceasing 

 during the night and early morning. The gi-eatest differ- 

 ence between the temperature of the flower and the general 

 atmosphere of the stove, was 11°; and, as in the first 

 blossom examined, so the central portion of the club of 

 abortive stamens was the part which exhibited the heat 

 most powerftilly; next the base of that club, and then the 

 stamens which were fertUe." 



The Colocasia odorata is a native of Pegu ; is a firee-grow- 

 ing plant under cultivation, and requires plenty of room 

 both for its roots and leaves ; the latter, indeed, it is which 

 give to the plant its truly noble aspect.— (Gardeners' Mag. 

 of Botany.) 



