116 MISSOURI BOTANICAL GARDEN BULLETIN 
Like many other members of the pea family, the peanut, 
through the instrumentality of certain bacteria living in 
little nodules on the roots, is able to collect and store free 
nitrogen from the atmosphere. This nitrogen, if allowed 
to remain in the soil, is a valuable and indispensable source 
of plant food. Most of the agricultural crops, instead of 
increasing the nitrogen supply in the soil, tend constantly 
to reduce it, consequently the value of the peanut, as well as 
other members of the pea family, is apparent in a system 
of crop rotation. A specimen on display in the Garden shows 
the root nodules. 
While the peanut has not been found in a truly wild state, 
species closely allied to it are natives of Brazil, and there 
seems to be every indication that our common peanut is a 
native of tropical America. Its introduction into the United 
States dates hack to the early period of colonization, where 
we find it becoming established along the James River in 
Virginia. It was not until about 1870, however, that the 
peanut became an agricultural crop of importance, but since 
that time its production has made rapid progress, and in 
1908 the crop of the United States was estimated at 
$12,000,000. 
About five varieties of peanuts are grown in the United 
States. Of these the “Virginia Runner” and “Virginia 
Bunch” produce large peas such as are commonly used in 
our markets for parching. The “African” or “North Caro- 
lina” produces a medium-sized pea used for shelling pur- 
poses and for the smaller grades of parching stock. The 
“Spanish” and “Valencia,” or “Tennessee Red,’ both have 
small peas and are extensively used for salted peanuts, pea- 
nut butter and peanut candy. 
It is not the pea alone, however, which is useful. The 
tops of the plants furnish hay with a feeding value equal 
to that of the best clover hays. Inferior peas furnish an 
excellent hog feed, as does also the cake obtained from the 
ground peas after pressing out the oil. The oil serves the 
same purpose as cotton seed oil and olive oil, and millions of 
bushels are annually used in its production. Peanuts are 
finding, in addition, ever-increasing use in the manufacture 
of peanut butter, peanut flour and vegetarian meat substi- 
tutes, as well as in various confections. 
THE CAPE LEAD-WORT. 
The plumbagos have been used extensively for a number 
of years as horticultural a but Plumbago capensis, so 
far, has surpassed them all in ease of culture, color of flower, 
