EUCALYPTUS TREES. 423 
Trapa bispinosa, Roxb.*—Middle and South Asia, 
extending to Ceylon and Japan ; found also in Africa 
as far south as the Zambesi. Here, in our culture, it 
lasts through several years. In some countries, for 
instance in Cashmere, the nuts form an important sta- 
ple of food to the population. To this species proba- 
bly belong T. Cochin-chinensis, Lour., and T. incisa, 
Sieb. and Zuce. 
Trapa natans, L.*—The ordinary Waternut. Mid- 
dle and South Europe, Middle Asia, North and Cen- 
tral ‘Africa. Recorded as an annual. ‘TT. quadrispi- 
nosa, Roxb., from Sylhet, is an allied plant. 
Trifolium agrarium, L. —The perennial Yellow 
Clover or Hop Clover. All Europe, Western Asia. 
Of considerable value in sandy soil as a fodder-herb. 
It is easily naturalized, 
Trifolium Alexandrinum, L.*—The Bersin Clover. 
North-eastern Africa, South-western Asia, South Eu- 
rope. Much grown for forage in Egypt. Recorded 
as annual. 
Trifolium fragiferum, L.—The Strawberry Clover. 
Europe, North Africa, Middle and North Asia. A pe- 
rennial species, well adapted for clayey soils. 
Trifolium hybridum, L.*—The Alsike Clover. Eu- 
rope, North Africa, Western Asia. A valuable, pe- 
rennial pasture herb, particularly for swampy locali- 
ties. 
Trifolium incarnatum, L. — The Carnation Clover. 
Middle and South Europe. Though annual only, it 
is valued in some of the systems of rotation of crops. 
It forms particularly a good fodder for sheep. A 
white-flowering variety exists. 
Trifolium medium, L.* — The Red, Zigag Clover. 
