638 MEDICAL BOTANY. 



the lobes. Stamens petaloid, one with half an anther on its edge. Style flat, straight, 

 almost free. Ovary 3-celled, with many ovules, granular. Fruit membranous, 3-valved, 

 with a deciduous, granular surface. Seeds round, smooth. 



An extensive genus of herbaceous tropical plants, usually with tuberous, 

 creeping rhizomes. Stems erect, with distant sheathing leaves. The inflo- 

 rescence is in terminal spikes or racemes. The flowers are in glumaceous 

 bracts. The species are most numerous in the western hemisphere. The 

 tuberous-rooted ones yield a fecula much resembling arrow-root, one variety 

 of which is known under the name of " Tous les mois" but it is very uncer- 

 tain from what species it is procured. Some writers have attributed it to 

 C. coccinea, but it is certainly not from the plant generally known under that 

 name to botanists ; by others it is said to be derived from C. achiras ; but 

 this is a Peruvian plant, whereas the Tous ies mois comes from St. Kitts. 

 Be its origin what it may, it is an excellent Arrow-root, and may always be 

 recognised by the great comparative size of its granules (see fig. 43). The 

 roots of several species are used as food in Peru, but those of O. achiras are 

 most esteemed. Martius states that the tubers of C. aurantiaca, glauca, &c. 

 of Brazil, are diuretic and diaphoretic, and are somewhat allied to Orris-root 

 in their action. 



The large leaves of Calithea cachibou are employed in South America for 

 a variety of domestic purposes; and it is stated by Kunth that the white, cre- 

 taceous coating of the under surface of the leaves, when triturated with 

 water, is considered to be efficacious in strangury {Nov. Gen. i. 328). Se- 

 veral of the Phryniums afford a tough fibre, which can be applied to all the 

 uses of hemp. 



Group XL VIII. — Orchidales. 



Order 113.— ORCHID KCEM.—Lindley. 



Flowers hermaphrodite, irregular, variable in form. Perianth adherent, variable, 

 herbaceous or coloured, membranous or fleshy, permanent or withering ; the parts in two 

 rows, rarely in three, free, or connected in various modes, often resupinate from a curve 

 in the ovary. Sepals 3, equal at base, or variously expanded there ; the two lateral are 

 in front when the ovary is twisted, and the third dorsal, sometimes surrounded by a true 

 calyx. Petals mostly 3, rarely 1, placed between the sepals; the 2 lateral like the dorsal 

 sepal, the third variously formed and appendaged. Stamens and style consolidated into 

 a central column. Stamens 3, opposite the sepals, one only fertile (except in Cypripe- 

 dium) ; anthers usually 2-celled ; cells divided by 2 — 4 partitions ; pollen powdery, or in 

 grains, or in wedge-like masses ; these masses free, or connected to the anther by a cau- 

 dicle. Ovary adherent, 1-celled, of 6 carpels ; style never distinct (except in Cypripe- 

 dium); stigmas usually confluent in a mucous disk. Capsule rarely fleshy, indehiscent, 

 pod-shaped, separating into 6 dry, rigid valves, with horizontal cells, 3 of which only con- 

 tain seeds. Seeds extremely numerous, minute. 



A very extensive and complicated order, consisting of perennial herbs or 

 shrubs, found in most parts of the world, having fibrous or fasciculated roots, 

 which are often fleshy, and containing much fecula or bassorin. The leaves 

 are flat, terete or equitant, usually sheathing, membranous, coriaceous or 

 rigid, never lobed, sometimes edged with cartilaginous teeth. The flowers 

 are either solitary, clustered, spiked, &c, but always furnished with a single 

 bract; often very fragrant, sometimes fetid, and not unfrequently without 

 odour. With very few exceptions, the plants of this order, as far as has 

 been ascertained, have no remedial properties. It is probable, however, that 

 a more extended study of them will show that many species are endowed with 

 active qualities. . 



