IPOM^A. 



appears certain that this plant furnishes the jalap of commerce. It is 

 however equally certain from the information furnished by the latter 

 gentleman that the following species is considered by the traders in 

 jalap to be extremely similar in quality, 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. 



810. I. orizabensis Pelletan Journ. chim. med. vol. x. p. 1. 

 Jalapa Macho of the Mexicans. In temperate parts of the state 

 of Oaxaca. 



Root tuberous, fleshy, with numerous oblong tubercles. Stem twining, 

 green, hairy. Leaves cordate acuminate mucronate, hairy, the earliest 

 ones hastate. Peduncles 2-3-flowered, twisted, 3 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. This description, as well as the last, 

 is taken from Don Juan de Orbegozo's letter. I presume that this 

 second sort of jalap is the Convolvulus Orizabensis of Pelletan, as 

 quoted by Mr. Pereira in the Med. Gaz. xx. p. 932. Dr. Schiede had 

 heard of it under its Spanish name of Jalapa Macho or Purga Macho, 

 or Male Jalap, but he had only seen the root, which appears very like 

 that of I. Purga. 



811. The slightly purgative Mechoacan root of Mexico is pos- 

 sibly produced by some species of this genus ; but the Convol- 

 vulus Mechoacannus of Willdenow or the Ipomaea Mechoacanna 

 of Nees and Ebermaier is too little known to be described. 

 Wood and Bache refer it to I. macrorhiza No. 807. 



812. I. operculata Martins (Jeticucu Piso bras. 93.) is said by 

 Guibourt to furnish a part of the Mechoacan of commerce, but 

 I do not find it described. 



813. I. tuberosa Linn. sp. pi. 227. Lunan Hort. Jam. i. 400. 

 Sloane nat. hist. jam. i. t. 96. f. 2. Jamaica, where it is 

 called Seven-eared or Spanish arbour vine. 



Root tuberous, as large as the human 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 2 black or dark brown 

 shaggy triangular seeds in each cell. All the parts purgative. Dr. 

 Barham thinks scammony might be obtained from it. 



814. I. cathartica Poiret encycl. meth. suppl. iv. 633. Con- 

 volv. africanus Kicols. nat. hist, of St. Domingo 260. Moist 

 places in St. Domingo. 



Stems twining, smooth, herbaceous. Leaves large, distant, long- 

 stalked, broad, oval, cordate, smooth, 3-lobed; the 2 lateral lobes oval, 

 shorter, acute ; the terminal oval-lanceolate, acuminate. Peduncles 

 axillary, usually 1-flowered. Flowers large, bright deep 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 

 397 



