THALAMIIXOE^. 505 



natives of the Cape of Good Hope, but the species have been much improved 

 by cultivation. They are commonly, but improperly, called Geraniums. In 

 their properties they are generally asti-ingeut, but P. tviste yields tubers 

 which are eaten at the Cape of Good Hope. From the leaves of a variety of 

 Pelargonium Radida. and also from some other species or varieties of Pelar- 

 gonium, as, for instance, P. odovatissimum, the true essential oil of geranium, 

 which is used in perfumery, is obtained. This must not be confoimded 

 with the so-called Geranium-oil of Turkey and of India, which is yielded by 

 a grass of the: genus Andropogon. This latter oil is that used in Turkey 

 for mixing with Otto of Roses. 



Natural Order 69. TEOPiEOiACE.^ — The Indian Cress 

 Order. — Character. — Smooth twining or trailing herbaceous 

 plants, -ft-ith an acrid juice. Leaves alternate, exstipnlate. 

 Flowers axillary. Sepals 3 — 5 {fig. 781), the upper one spurred; 

 valvate, or rery slightly imhricated in estivation. Petals {fig. 

 781) 1 — 5, hypogynous, raore or less unequal; (estivation cow- 

 volute. Stamens {fig. 781) 6 — 10, somewhat perig}-nous, dis- 

 tinct; anthers 2-celled. Ovary of 3 {fig. 781) or 5 carpels; 

 style 1 ; stigmas 3 or 5. Fndt indehiscent, usually consisting of 

 3 carpels arranged round a common axis, from which they ulti- 

 mately separate, each carpel containing one seed. Seeds large, 

 exalbuminous ; emh^yo large ; rndide next the hilum. 



Diagnosis. — Smooth trailing or twining herbs, with alternate 

 exstipnlate leaves, and axillary flowers. Flowers irregular and 

 unsymmetrical. Sepals more or less valvate in jestiyation, upper 

 one spurred. ^Estivation of petals convolute. Stamens more or 

 less perigynous, distinct. Ovary superior, of 3 or 5 carpels, with 

 one pendulous ovule in each ; style single. Pruit without a 

 beak, usually composed of three pieces, which are indehiscent, 

 and each contains 1 seed. Seeds large, exalbuminous. 



Distribution, ^-c. — Chiefly natives of South America. Ex- 

 amples of the Genera: — Tropseolum, Chymocarpus. There are 

 about 40 species. 



Propirties and Uses. — Generally acrid, pungent, and anti-scor- 

 butic, resembling the Cruciferse. The unripe fruit of Tropeohim 

 rnajus, which is commonly known as the Indian Cress or 

 Grarden Nasturtium, is frequently pickled, and employed by 

 housekeepers as a substitute for Capers. Most of the Tro- 

 pcBolums have tubercular roots, some of which are edible, as T. 

 tuberosum. 



Natural Order 70. Limnanthacrs;. — The Limnanthes Order. 

 — Diagnosis. — This is a small order of plants included by Lind- 

 ley in the Tropseolacese, with which it agrees in its general 

 characters; but it is at once distinguished from that order by 

 having regular fxowers ; more evidently perigynous stamens ; 

 and erect ovules. It forms a sort of transition order between 

 Thalamifloral and Calycifloral Exogens, although, perhaps, it 

 should be included in the latter. 



Distribution, cfc. — Natives of North America. Examples 



