280 BULBS AND TUBEROUS-ROOTED PLANTS. 
difficult to manage, not thriving in the open border, as 
they must be amply protected against frost and too much 
moisture, and in the greenhouse they do not make suffi- 
cient root growth to supply the leaves with nourishment. 
The genus seems adapted only to its native habitat. 
The species were formerly included with the Ixias (Page 
166), and similar treatment is very near to their necessi- 
ties. See also Montbretia, Page 233. 
T. aurea.—Also known as Crocosma aurea, is 
the easiest to manage, and the one most generally culti- 
vated. They succeed well as border plants, in light soil, 
perfectly drained, but they must be protected against 
frost. Although they do not flower until August or 
September, the bulbs must remain in the ground during 
winter, as they cannot remain long out of ground with- 
out injury. ‘To keep them dry during winter would be 
fatal to them, so the only resource left is to protect them 
in the bed, or take them up after flowering and keep 
them in pots. Neither of the methods will find favor 
with the American gardener, who has so many resources 
from which to draw, either for the garden or greenhouse. 
TROPHZOLUM. 
Nasturtium. 
The tuberous species of this genus are very interest- 
ing plants, the best known being: 
T. tricolorum.—sSo named because of its three- 
colored flowers, orange, red and purple. The tubers of 
this species are about an inch in diameter, and should 
be planted on the surface of the soil, either in pots, or 
on the greenhouse bench, in light fibrous soil. From 
these tubers will arise delicate hair-like stems, which 
increase in size as they grow, being three times the 
thickness at a distance of six feet from the bulb. These 
stems are so delicate that it is necessary to provide a 
frawe or trellis for their support, as they are entirely 
