410 ORDER GERANIACEJE, OR GERANIUM TRIBE. 



seed will produce a plant having light-red flowers ; or if we 

 cause a sort with large unsightly flowers to intermix with one 

 having small neat flowers, we shall probably obtain a variety 

 having large flowers that are as neat in appearance as those of 

 the small flowered kind. This intermixture will only take 

 place, however, among varieties of the same species, or among 

 species nearly related to each other ; there are some Pelargo- 

 niums which will not hybridize together ; and the Pelargonium 

 is not fertile with the Geranium. The Geraniaceae are not 

 marked by any very active properties ; they possess, however, 

 some astringency, and also an aromatic resinous principle. The 

 stem of a foreign species of Geranium burns like a torch, and 

 gives out an agreeable odour. The root of an American species 

 is considered a valuable astringent, and is known by the name 

 of Alum root. The British species commonly termed Herb- 

 Robert, is held in repute for its medicinal virtues in some parts 

 of the country. 



575. Very nearly allied to the Geraniacese is the small order 

 TROPJEOLE^E, of which the members are all natives of tropical 

 America, but of which one species is now commonly naturalised 

 in our gardens under the name of Nasturtium (which is, how- 

 ever, an incorrect one), sometimes abbreviated into Sturtion, or 

 occasionally Trophy-cress. The common name refers to the 

 similitude it bears in taste, smell, and general properties, to the 

 true Nasturtia or Cresses ; a similitude so great, that the same 

 insects resort to and feed on both. The plant is cultivated in Bri- 

 tain for the sake of its unripe ovaria, which possess an agreeable 

 pungency of flavour, and are pickled to be used like Capers as a 

 sauce to boiled mutton. This order differs from the last, chiefly 

 in the following particulars. The sepals of the calyx are un- 

 equal in size, and one of them is provided with a long distinct 

 spur (of which a rudiment, however, may be traced in Pelar- 

 gonium) ; this is subject to great varieties of form ; indeed a 

 series of monstrosities, such as may often be easily collected from 

 a single bed of these plants, presents many curious phenomena. 

 There seems a great tendency towards the return to a regular 

 form, by the equalisation of the sepals ; in some instances the 



