522 ORCHIS TRIBE; SALEP. GINGER TRIBE. 



travellers, who have to carry their supplies with them into deserts 

 and uninhabited countries. So high a nutritive power has been 

 assigned to it, that it has been asserted that one ounce of Salep, 

 boiled with an equal quantity of the stiff glue or animal jelly 

 known as portable soup, in two quarts of water, will suffice for 

 the daily nourishment of an able-bodied man. Some of the 

 South American species contain a viscid substance, which, when 

 separated by boiling, serves as a sort of glue, which is used by 

 the Brazilians for sticking together their skins of leather. There 

 is scarcely any other way in which this order is of any direct 

 utility to Man. 



698. Of the next order, SCITAMINE^E, the Ginger tribe, there 

 are no British representatives ; but its structure will be very 

 easily comprehended, as we now return to a nearly regular type 

 of structure. They are all aromatic herbaceous plants, only 

 coming to perfection between the tropics ; and they are nearly 

 all characterised by possessing a rhizoma, which creeps along the 

 ground, and from the sides of which the leaf and flower-stalks 

 are annually shot up. The flowers arise from expanded scaly 

 bodies, which are clusters of bracts, one for the protection of each 

 pair of buds. The ovarium, as in the Orchideas, is inferior ; and 

 the calyx, which arises from its summit, is tubular, and is formed 

 by three sepals adherent nearly to their points. Within this are 

 two whorls of leafy organs, the outer of which is to be regarded 

 as the true corolla, whilst the inner one consists of transformed 

 stamens. In each whorl there are three segments ; those of 

 the outer whorl, or petals, are partly adherent so as to form a 

 tube, and are nearly equal one being sometimes larger than 

 the rest or differently shaped, so as to show some affinity with 

 the Orchideae. Of the inner whorl of transformed stamens, one 

 is usually very much enlarged, like the labellum of Orchideae, 

 whilst the others are almost undeveloped. Within this whorl, 

 there are three distinct stamens, of which, however, only one 

 usually bears pollen; but this is quite distinct from the pistil. 

 The ovarium is usually three-celled, though sometimes im- 

 perfectly so, the partitions not being complete, so as to ap- 



