273 



IPOM^A. 



IRIDACEjE. 



271 



Tinian, &c. Its root is perennial. The stems twining, several 

 fathoms long, from 3- to 4-sided, a little downy, with winged angles ; 

 leaves stalked, varying in form from cordate to linear, all pointed 

 and lobed, or angular and downy; peduncles axillary, downy, many- 

 flowered ; flowers large and white ; bracts oval, concave, velvety, 

 deciduous ; ovary seated on a large glandular disc ; stigma 2-lobed ; 

 capsules involved in the dry calyx, absolutely 4-sided, 2-celled, 

 opening at the apex by a kind of operculum ; seeds round, black, 

 one in each cell. The root has been long employed in India as a 

 common purgative. The bark of the roots is the part employed by 

 the natives, as it contains all the active properties ; they use it 

 fresh, rubbed up with milk. About six inches in length of a root as 

 thick as the little finger they reckon a common dose. (Roxb.) It is 

 reckoned an excellent substitute for jalap, and is free from the 

 nauseous taste and smell of that drug. The plant is a native of all 

 parts of continental and probably of insular India also, as it is said 

 to be found in the Society and Friendly Isles and the New Hebrides. 



/. macrorhiza is supposed to be the Convolvulus JcUapa of Linnaeus. 

 It is a plant inhabiting the sandy soil of Georgia and the Carolina", 

 with white insipid farinaceous roots, weighing from 40 to 50 Ibs. It 

 is said to possess no purgative properties, but, like Batatai, consists 

 chiefly of saccharine and farinaceous matter. 



I. pandurata is common in North America, in sandy fields and by 

 fences, from Canada to Florida. It is the Mechameck of the Indians. 

 It has a very large root, 2 or 3 feet long and as thick as the arm, of a 

 yellow-ochre colour. The stem is downy ; leaves on long stalks, 

 broadly cordate, entire, acuminate, slightly repand ; peduncles 

 many flowered, cymose longer than the petioles ; corolla large, cam- 

 panulate, white, dull purple towards the base ; stamens white, the 

 length of the tube. The powdered root acts like rhuburb ; it requires 

 to be given in larger doses than jalap. It has an American reputation 

 a remedy for calculous affections, and in cases of gravel. 



7. Purga (I. Jalapa of Nuttall) is found on the eastern declivity 

 of the Mexican Andes near Chiconqniaco, and near San Salvador 

 on the eastern face of the C6fre de Perote, at an elevation of about 

 6000 feet above the sea; and on the mountains near Orizaba. It 

 has a tuberous fleshy root, with numerous roundish tubercles. Stem 

 smooth, brownish, very slightly rough ; leaves stalked, the first 

 hastate, the succeeding ones cordate, acuminate, mucronate, smooth ; 

 peduncles axillary, 2-flowered, twisted, the length of the corolla; 



sepal* obtuse, mucronate, smooth ; corolla purple, with a long some- 



v.li it . clavate tube, and an undulated limb with 5 plaits; filaments 



smooth, unequal, longer than the tube of the corolla; anthers linear, 



ting ; stigma capitate, deeply furrowed ; capsule 2-celled ; cells 



2-eeded. It has long been employed aa a medicinal agent, and 



HAT. HIST. DIV. VOL. III. 



is considered by the traders in jalap to be extremely similar in quality 

 to the true plant ; and as it is the more abundant and larger of the 

 two, at least in some districts, the probability is that it also forms a 

 part of the imported samples of this drug. 



/. Orizabensis is native of the temperate parts of the state of Oaxaca. 

 It has a tuberous fleshy root, with numerous oblong tubercles ; stem 

 twining, green and hairy ; leaves cordate, acuminate, mucronate, 

 hairy, the earliest ones hastate ; peduncles 2-3-flowered, twisted, 

 three times as long as the corolla ; sepals oblong-obtuse, mucronate, 

 hairy; corolla purple, campanulate, with a regular tube inflated in 

 the middle, and a wavy limb with 5 plaits ; stamens shorter than 

 the tube, hairy at the base ; capsule 2-celled ; cells 2-seeded. The 

 Spanish name of this plant is Jalapa Macho. 



/. tuberosa is found in Jamaica, where it is called Seven-Eared or 

 Spanish Arbour-Vine. The root is tuberous, as large as a man's 

 head ; stems 200 or 300 feet long, purplish at the extremities ; leaves 

 smooth, downy beneath, palmate, or 7-lobed ; the lobes much smaller 

 at the side than in the middle, narrow, lanceolate, acuminate ; 

 peduncles many-flowered ; flowers pale yellow, sweet scented ; capsule 

 as large as a walnut, membranous, shining, brown, 2-celled, with two 

 black or dark-brown shaggy triangular seeds in each cell. All the 

 parts are purgative. Dr. Barham thinks scammony might be obtained 

 from it. 



/. cathartica. is found in moist places in St. Domingo. The stems 

 are twining, smooth, and herbaceous ; leaves large, distinct, long- 

 stalked, broad, oval, cordate, smooth, and 3-lobed ; the two lateral 

 lobes oval, shorter, acute ; the terminal oval lanceolate, acuminate ; 

 peduncles axillary, usually 1-flowered; flowers large, deep bright-red ; 

 tube of the corolla thick, inflated, contracted and cylindrical at the 

 base, an inch and more long, pale green ; the limb broad, 5-lobed ; 

 stamens shorter than the corolla ; stigma capitate. The roots furnish 

 a resinous substance used as a purgative in St. Domingo. Its use is 

 not however very safe, as it is apt to produce excessive purgation. 



(Lindley, Flora Medico, ; Royle, Materia Medica.) 



IPS, a genus of Insects belonging to the order C'uleoptera, to the 

 section Pentamera, and the family Empidce. The body is of an oblong- 

 oval form and depressed, with the third joint of the anteunte longer 

 than the second, and the club large and rounded. The species are 

 generally found under the bark of decayed trees. They are chiefly 

 confined to Europe. The British species, of which there are four or 

 five, are rare. 



IRIDA'CE^E, Iridi, a natural order of Endogenous Plants, usually 

 with equitant leaves, and a rhizoma or cormus for their stem, but 



Leaves and flowers of SltyriHeh'.nm ttrint, m. 

 ripe fruit. 



1, the ^;IIM('JU ; 2, the 



