616 



MEDICAL BOTANY. 



The species are herbaceous, or shrubs ; often with fleshy corms, stemless, 

 or arborescent, or climbing by aerial roots. Leaves sheathing at base, con- 

 volute in vernation, sometimes compound, often cordate. They are princi- 

 pally natives of tropical climates, but a few occur in temperate regions ; in 

 the former they are arborescent or shrubby, whilst in cold and temperate 

 countries they are small and herbaceous. They are in almost all cases acrid, 

 and in some species so much so as to render them dangerous poisons. Sir 

 Wm. Hooker (Exot. Flor. 1) states that Dieffenbachia seguina, or Dumb- 

 cane, is one of the most venomous of all known plants ; if the rhizome be 

 chewed, it causes a dangerous swelling of the tongue, destroying all power 

 of speech, and that even the slightest application of the juice of the spadix to 

 the lips gives great pain. Browne (Hist. Jam.) says that the stem is used 

 in the West Indies to produce granulation in sugar. In other species, again, 

 this acridity is so much diminished that the roots and leaves are used as food, 

 when properly cooked. The order has been divided into several tribes. 



1. CryptocoryNjE. — Stamens distinct from pistils, which are several, grouped round the 

 base of the spadix in a many-celled ovary. 



The species of this tribe do not appear to possess any striking qualities, 

 and are little known. 



2. DracunculjE. — Stamens and pistils numerous, with rudimentary organs interspersed. 

 Spadix naked at the end. Cells of anthers larger than the connectivum. 



Almost all the plants of this tribe are acrid, but afford a fecula from their 



cormus that is edible when 



Fig. 276. 



A. triphylla. 



deprived of the volatile prin- 

 ciple. Thus, those of Arum 

 maculatum, when grated, and 

 repeatedly washed, and sub- 

 jected to the action of heat, 

 furnish a bland and nutritious 

 amylaceous powder which 

 is known in England as Port- 

 land arrow-root, from being 

 principally manufactured in 

 that place. A. indicum is 

 much cultivated in some parts 

 of India for its succulent stems 

 and small tubers. 



The tubers of Amorpho- 

 phallus trilobatum, of the 

 East Indies, are very acrid, 

 and are used in cataplasms to 

 maturate malignant tumours, 

 and are also applied in the 

 bites of venomous snakes ; at 

 the same time a small portion 

 is taken internally (Rox- 

 burgh). The large corms of 

 other species of the Indian 

 Archipelago afford an edible, 

 starchy substance. 



Ariscsma triphylla is re- 

 cognised as officinal in the 

 United States Pharmacopoeia, 



