GESNERACEJB ERICACEJE. 445 



both in temperate and warm countries. There are 27 known genera, 

 and 375 species. Examples Lobelia, Siphocampylus, Clintonia, 



924. Acridity prevails more or less in the order. The milky juice 

 of some, such as Lobelia urens, is said to be vesicant. Lobelia inflata, 

 Indian Tobacco, a native of North America, is used medicinally as a 

 sedative, expectorant, and antispasmodic. It is chiefly administered in 

 cases of asthma. The whole plant is active, but the root and capsules 

 are said to be most powerful. In large doses, the plant acts as a nar- 

 cotico-acrid poison. It owes its properties to a bitter principle called 

 Lobelein. The root of Lobelia syphilitica is acrid and emetic. The 

 milky juice of some of the plants of the order contains a considerable 

 quantity of caoutchouc. 



925. Order 112. Gesncrace*e, the Gesnera Family. (Monopet. 

 Perigyn.) Calyx partially adherent, 5-partite ; aestivation valvate. 

 Corolla monopetalous, tubular, more or less irregular, 5-lobed; aestiva- 

 tion imbricated. Stamens 4, didynamous, with the rudiment of a 5th, 

 rarely 2; anthers dithecal, with a thick swollen connective. Ovary 

 partly free, unilocular, formed by two carpels with parietal placentas, 

 which are 2-lobed; ovules indefinite, anatropal; style continuous with 

 the ovary; stigma capitate, concave, glandular or annular. Disk sur- 

 rounding the base of the ovary. Fruit capsular or succulent, 1 -celled, 

 more or less adherent. Seeds 00, minute; testa thin, finely and 

 obliquely veined; embryo erect in the axis of fleshy albumen; radicle 

 pointing to the hilum. Herbs or shrubs, often springing from scaly 

 tubers, with opposite or whorled, rugose, exstipulate leaves, and showy 

 flowers. They are found principally in the warmer regions of America, 

 and are interesting chiefly on account of their beauty, for they do not 

 appear to possess any important qualities. There are 22 known genera, 

 and upwards of 120 species. Examples Gesnera, Columuea, Gloxinia, 

 Achimenes. 



926. Order 113. Kricacwe, the Heath Family. (Monopet. Hypog.) 

 Calyx 4-5-cleft, nearly equal, persistent. Corolla inserted at the base 

 of the calyx, or hypogynous, monopetalous (fig. 298), 4-5-cleft, some- 

 times tetra- or pentapetalous, regular or irregular, often marcescent ; 

 aestivation imbricated. Stamens definite, equal in number to the seg- 

 ments of the corolla, or twice as many, inserted with the corolla, and 

 either free from it or attached to its base; anthers 2-celled, cells hard 

 and dry, bifid, (fig. 336), usuaUy having appendages at the base 

 (fig. 338 a) or apex, dehiscing by apicilar pores (fig. 340) or clefts. 

 Ovary free, surrounded at the base by a disk or scales, multilocular ; 

 ovules 00, attached to a central placenta; style 1, straight; stigma 1, 

 undivided (fig. 408) or toothed. Fruit capsular or baccate, many- 

 celled, with loculicidal or septicidal dehiscence. Seeds 00, minute ; 

 embryo cylindrical, in the axis of fleshy albumen; radicle next the 

 hilum. Shrubs, undershrubs, or herbaceous plants, with evergreen, 



