287 



remarked that ia Dracontium polyphyllum and foetidum, in which there is 

 no albumen, the phiniula consists of imbricated seniles, and that it is some- 

 times double or even triple. In the former of these plants the external 

 scales, in germination, quickly wither away, when other internal and larger 

 ones appear, and remain for some time round the base of the primordial leaf, 

 before the developement of which no rootlets are emitted. Prodr. 334. A 

 similar economy has been noticed by Du Petit Thouars, in his genus Ouvi- 

 randra. In Tacca it is probable that there are several germinating points 

 upon the embryo, analogous to the doable or triple plumula of Dracontium : 

 hence embryos of such a kind may be said to be tubers found in the seed 

 itself. Mr. Brown considers a relation to be established between Aroidese 

 and Aristolochise by means of Tacca, in which the ovarium is inferior. 

 Agardh distinguishes Acoroidese from Aroideaj by their capsular fruit. 



Geography. Natives of all tropical countries abundantly, but of 

 temperate climates rarely, not extending in Europe further north than 64° 

 north latitude, in the form of Calla palustris, which inhabits the deep, 

 muddy, frozen marshes of southern Lapland. In cold or temperate climates 

 they are usually herbaceous, while in tropical countries they are often arbo- 

 rescent and of considerable size, frequently clinging to trees by means of 

 their aerial roots, which they protrude in abundance. In America, according 

 to Humboldt {Distr. Gcogr. 196), their principal station is on the sub- 

 montane region between 1200 and 3600 feet of elevation, where the climate 

 is temperate and the rains abundant. In the Andes, Pothos pedatus and 

 P. quinquenervius rise to the height of 8400 feet. 



Properties. A principle of acridity generally pervades this tribe, and 

 exists in so high a degree in some of them as to render them dangerous 

 poisons. The most remarkable is the Dumb Cane, or Caladium Se- 

 guinum, a native of the West Indies and South America, growing to the 

 height of a man : this plant has the power, when chewed, of swelling the 

 tongue and destroying the power of speech. Dr. Hooker relates an account 

 of a gardener, who " incautiously bit a piece of the Dumb Cane, when his 

 tongue swelled to such a degree that he could not move it; he became 

 utterly incapable of speaking, and was confined to the house for some days 

 in the most excruciating torments." Exot. Bot, 1. The same excellent bota- 

 nist adds, that it is said to impart an indelible stain to linen. P. Browne 

 states, that its stalk is employed to bring sugar to a good grain when it is too 

 viscid, and cannot be made to granulate properly by the application of lime 

 alone ; Arum ovatum is used for the same purpose. The leaves of Arum 

 esculentum excite violent salivation and a burning sensation in the fauces, 

 as I have myself experienced. The fresh leaves of Dracontium pertusum 

 are employed by the Indians of Demerara as vesicatories or rubefiants in 

 cases of dropsy. Milk in which the acrid root of Arum triphyllum has 

 been boiled has been known to cure consumption. Dec. Notwithstanding 

 this acridity, the flat under-ground stems, called roots, and the leaves of 

 many Aroidese, are harmless, and even nutritive when roasted or boiled, as, 

 for instance, the roots of Arum esculentum, Colocasia, mucronatum, viola- 

 ceum, and others, which, under the names of Cocoa root, Eddoes, and Yams, 

 are common articles of food in hot countries. The roots (cormi) of the 

 Arum maculatum are commonly eaten by the country people in the Isle 

 of Portland ; they are macerated, steeped, and the powder obtained from 

 them is sent to London for sale under the name of Portland Sago. Enc. of 

 PL 800. Medicinally, the root in its recent state is stimulant, diaphoretic, 

 and expectorant. The root and seeds of the Skunk Cabbage, Symplocarpus 

 foetida, are powerful antispasmodics; they are also expectorants, and useful • 

 in phthisical coughs. They have considerable reputation in North America 



