THE NASTURTIUM. 49 



green-house. The best known of these is Tropaolum 

 tricolorum, with flowers marked red, black, and yellow, 

 which has tuberous roots, and such very weak and slender 

 stems, that it is found necessary always to train them 

 over a wire frame, as they are quite unable to support 

 themselves. In Paxton's " Magazine of Botany " it is 

 stated that the tuber of the root should not be buried, 

 but only placed on the surface of the soil, so that the 

 fibrous roots may penetrate it. This, it is said, will 

 enlarge the size of the tuber in " a truly astonishing 

 manner ;" and though the plants will not appear healthy 

 the first season, they will afterward become extremely 

 vigorous. It is also recommended to use double pots 

 for these plants, and fill up the interstices with river 

 sand, which should always be kept moist. Substantially 

 the same plan has been followed in this country for 

 many years, and found to succeed well. T. brachyceras 

 may be treated in the same manner, and it would prob- 

 ably succeed with T. tuberosum, a species which it is 

 very difficult to throw into flower under ordinary treat- 

 ment, but which grows best in the open ground, in rich 

 soil, and with plenty of air and light. 



T. peregrinum, the Canary Bird Flower, was formerly 

 considered a green-house plant, but it is now found 

 much better to treat it as a half-hardy annual, raising the 

 seeds on a hot-bed, and planting them out in May near 

 some trellis-work or other support, which the plant will 

 soon cover in the most graceful manner, producing 

 hundreds of its elegant, fringe-like, pale-yellow flowers. 

 It is propagated from cuttings and by seeds. 



