COLOCASIA ODOBATA. 
1 
COLOCASIA ODORATA. 
771 HE fragrance of this species renders it a desu-able subject in all collections of stove plants. The diffused 
il odour, as it pervades the entire atmosphere of a hot house in wliich the plan t is blooming-, resembles that 
of Mig-nonette; but the more powerful and concentrated fi-agrance which is experienced on nearercontact 
with the plant, is of the sweet aromatic natiu-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 aroideous plants, which give such a 
trojiical air to collections in wliich thej' occm\ Tlris species grows with a caudex of thi'ce to six feet 
high, and from four to six inches in diameter, and is then crowned at the top with a head of large naiTOwly 
cordate leaves, supported on long stout footstalks, and traversed by jirominent veins. The flowers grow 
from the axils of the leaves towards the centre of the plant, and stand erect among the foKage. The 
spathe is about a span long, conti'acted below the middle, and then expanding into a concave or boat- 
shaped membrane, which, at first, stands erect, encii-cKng the spadix, but ultimately bends over it like 
a hood. The spathe is green at fh-st, hut acquii-es a yellowish hue v,'hen at matm-ity. 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 cultivated in our hot-houses, is j-et produced in considerable quantities, when the plant is 
growing in its natural climate. The secretion is formed exclusively on the lower face of the leaf, and is 
confined to the axils of its principal nerves, where the cellular tissue produces it, and from which 
points, this waxy substance extends sometimes over nearly the whole mferior surface of the foliage. 
In the cultivated plant it only exists in small scales, at the utmost not lai-ger than the hmnan nail.* 
A curious property possessed by the plants of this family, is the evolution of heat at certain periods 
of thefr inflorescence. This has been noticed by various observers, but apparently fir-st by Lamarck, 
who, in 1777, made the discovery upon Arum italicum. The most exact experiments, however, are 
those of M. Adolphe Brogniart, made in 1834, upon a plant of the Colocasia odorata, which de- 
veloped fom- flo-^^ers in the space of a month. 
" The first flower began to expand on the 4ttL of March, but it was not till the 6th that the escape 
of pollen from its anthers commenced, and the increase of temperature on the spadix was percejjtible to 
the touch. A very small thermometer, when applied to the flower, indicated a temperatm-c in the air 
of 23 degrees eentrigrade, while the spadix, close to the fertUe stamens, was 26 degrees, and the club 
formed by the abortive stamens was 30 degrees, the difference being 7 degrees. The heat of the flower 
gradually diminished, and, in the evening, its temperature was the same as that of the stove. It is 
remarkable, however, that, while all the other Aroideac that have been examined on this point, appear, — 
when the heat has once disappeared, — never to regain it, the plant imdcr consideration exlubited the 
same increase of tempcratm-c at the same horn- (2 p.m.) of the following day, and for four days it 
* Botanical Magazine, t. 3935. 
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