LESPEDEZA. The genus lespedeza of the family of legumi nosae is represented by 125 species all natives of eastern Asia and eastern North America. This peculiar distribution has given rise to the theory that these forms developed in eastern Asia from which some migrated in past geologic time by way of a land con nection in the north to North America and so down the east coast. This is believed to have occurred before the emergence of the western part of the North American continent. Later, the species established on the eastern border were prevented from moving west by the barrier of desert and mountains.
Of the known species, about 20 are natives of North America. None of the American species occurs in the Orient and none of the oriental species is indigenous to America. The lespedezas may be roughly grouped as annuals, herbaceous perennials, and shrubs. Where the current growth is not cut down by winter cold, the latter may attain a height of I oft. or more. Some of these shrubs, as L. bicolor and L. Japonica in the United States and L. delavayi in France, have long been known as ornamentals. Most of the known species, including those indigenous to America, are herbaceous perennials. In these the stems die after seeding and new growth comes each year from the crown.
Only two species are annuals, L. striata and L. stipulacea, and these two with one herbaceous perennial, L. sericea, are the only ones useful in agriculture.
The Economically Important Species: Lespedeza Striata. —The common lespedeza, formerly called Japan clover, is be lieved to have been brought to the United States in the early years of the 19th century. It probably came with a cargo of tea from China or Japan and escaped at Charleston or Savannah. The plant was first recognized at Monticello, Ga., in 1846. The plant then collected is still in the Gray herbarium at Harvard. Lespe deza spread rapidly during the war between the States and was well known in Alabama and Mississippi in 1867. In 188o, it was commercially used for hay in Louisiana. In 187o, it was known in parts of Tennessee and in 1887 in northern Virginia. The earlier maturing strains have since carried the species farther north and it is now established as far north as central Indiana.
L. striata is a slender plant with trifoliolate leaves. The leaflets are oval to oblong about lin. long by to wide, and slightly rounded at the end. Three varieties of L. striata are recognized: the common or unimproved; the Kobe, a variety with larger leaves and seed, and coarser growth, found in Japan in 1920; and Tennessee 76. The last named was selected by the late S. J. Essary of the University of Tennessee as the best of a number of selections. It is erect in habit, tall, and a heavy yielder of hay. In leaf and seed, it is indistinguishable from the common.
Korean lespedeza is a strong growing plant with larger and broader leaflets than those of L. striata and makes a larger growth. Isolated plants are spreading in habit. It matures about one month earlier than L. striata and is therefore suited to a more northern range.
The seeding habit also differs from that of L. striata. While in the latter seeds are borne in the axils of leaves or branches all along the stem, in Korean lespedeza seeds are borne in the leaf axils at the ends of branchlets only. At maturity the leaves on these branchlets turn forward so that the tip of the branch resembles a small cone. Besides the standard Korean, three vari eties of L. stipulacea are recognized, although none of them is much used. The Harbin is an extra early dwarf variety which has matured seed as far north as Winnipeg, Canada. An early Korean maturing two weeks earlier than the standard has been introduced into northern Illinois and Iowa, and a late Korean, maturing two weeks later than the standard, is under trial in the South.