EUCALYPTUS TREES. vial 
likely to remain free from the attack of aphis. Chem- 
ical constituents : a peculiar fixed oil, crystalline sin- 
apin, the fatty sinapisin, Myron-acid and Myrosin. 
Brassica oleracea, L.—An annual or biennial coast- 
plant, indigenous to various parts of Europe. it is 
mentioned here with a view of showing that_it might 
be naturalized on our rocky and sandy sea -shores. 
From the wild plant of the coast originated vari- 
ous kinds of cabbages, brocoli, cauliflower, Brussel 
sprouts, kale, kohlrabi, ete. Other races of this spe- 
cies are collectively represented by Brassica Rapa, L. 
(B. campestris, L.), the Wild Navew, yielding most 
of the varieties of turnips, some with other cultivated 
forms transferred to us from ancient times. Again 
other varieties are comprehended within Brassica 
Napus, L., such as the Swedish and Teltower turnips, 
while the rape seed, so important for its oil (Colza), 
is also derived from a form of B. Napus. The rape 
should be produced here as an agrarian produce, giv- 
ing a rapid return, wherever it should remain free of 
aphis. The hardier turnips could be produced on our 
highest Alps, as they are grown still within the arc- 
tic circle, and, according to Dr. J, Hooker, at a height 
of 15,000 feet in the Himalaya mountains. 
Butomus umbellatus, L.—The Flowering Rush. 
Europe, North and Middle Asia. This elegant pe- 
rennial water-plant is mentioned here more for its 
value in embellishing our lakes and water-courses 
than for the sake of its roots. The latter, when roast- 
ed, are edible. The plant would live in our sub-al- 
pine rivulets. 
Bromus unioloides, Humboldt.* (B. Schraderi, 
Kunth. )—Here called the Prairie Grass. From Cen- 
