POTATOE. ORDER SCROPHULARINE2E. 485 



others can be profitably grown, but that it can be cultivated 

 there at a small expense, and is less likely to be affected by 

 unfavourable states of the weather, than are most other crops. 



660. The last order of this group which will be here noticed, 

 is that of SCROPHULARINE.E, which may be explained as the 

 Foxglove or Snapdragon tribe, these being two of the species 

 best known, and at the same time most characteristic of it. This 

 order is remarkable, like the Labiatse, for the irregularity in the 

 form of its flowers, which is even carried (in many species) much 

 further than it ever is in that group ; but it is strikingly different 

 from it in properties ; for instead of being harmless and agreeable 

 to the taste, many of the plants belonging to it are, like the 

 Solaneae, virulent poisons, having strong acrid and narcotic 

 properties, and all are suspicious. Instead of being, however, 

 like a great part of the Solaneae, of a dark and lurid aspect, which 

 might almost lead us to suspect their injurious character, the 

 plants of the Foxglove tribe are for the most part handsome, 

 often possessing very brilliantly-coloured flowers. This order 

 could not be readily distinguished from the Labiatae by anything 

 in the structure of its calyx, corolla, or stamens, which last are 

 (as in the Labiatae) didynamous; but they are at once known by 

 the structure of the seed-vessel, which does not present externally 

 a division into four lobes, but only into two ; each of the two 

 cells encloses a large number of ovules, instead of containing only 

 two; and in ripening, the seed-vessel forms a distinct capsule 

 with two valves. By this last character alone, this group is 

 separated from the Labiates in the Linnasan arrangement, being 

 placed in the second order, Angiospern^ia ; the name of which 

 refers to the enclosure of the seeds in a capsule, contrasted with 

 their supposed nakedness in the preceding one. This Linnasan 

 order also includes the OROBANCHE^E, or Broom-rape tribe, which 

 is nearly allied to the Scrophularinea?, differing from it chiefly 

 in the absence of leaves, and in its parasitic habits, which resemble 

 those of the Dodder, except that the former attach themselves 

 to the roots of other plants, whereas the Dodder derives its 

 nourishment from their stems. 



661. The common Foxglove (Digitalis purpurea) is one of the 



