LESPEDEZA
Lespedeza spp., family LeguminosaeLespedeza is a crop of major importance in southeastern United States. Roughly 164,000 acres were grown for seed production in 1970, producing 36.8 million pounds of seed, valued at $5.2 million. Slightly more than 2 million tons of hay, valued at approximately $50 million, were produced in 1968, the last year the USDA Agricultural Statistics reported on the acreage of this crop.
Lespedeza is grown for hay and pasture, soil improvement, erosion control, seed, and its benefit to wildlife (game birds and deer).
Two types of lespedeza are grown - annual and perennial. The annuals, which are the most important (McKee l948),include 'Common' and 'Kobe' (L. striata (Thunb.) H. and A.) and 'Korean' (L. stipulacea Maxim.) (Elrod 1954). The most common perennial is 'Sericea' (L. cuneata (Dum.) G. Don) also known as shrub lespedeza (fig. 121). Three other perennial or shrub lespedezas, grown to a limited extent, are L. bicolor Turcz., L. intermedia (Wats.) Britt., and L. japonica Bailey.
[gfx] FIGURE 121. - Dense growth of 'Serica' lespedeza, which provides forage and cover for wildlife.
Plant:
The lespedezas are recognized by the small trifoliate leaves, l/4 to l/2 inch long, the individual flowers, and the one-seeded jointless pods. The annual lespedezas are often confused with hop clover although there are important differences. Hop clover seeds germinate in the fall, and the plants stay green throughout the winter and then die in early summer. Lespedeza seeds germinate in the spring, and the plants grow slowly until about the time hop clover dies. Also, the flowers differ in color (Essary 1921, Kinney and Kenney 1925). The plants are slightly spreading to erect, depending upon the thickness of the stem, and from a few inches to several feet tall, depending upon the species. The annuals grow to a height of 5 to 36 inches, depending upon soil moisture and fertility. The bush lespedezas reach 5 to 7 feet. At maturity, the leaves on Korean lespedeza turn forward so the branch tip resembles a cone (McKee 1940). In general, the growth habits of the annual lespedezas are like alfalfa (Pieters 1939a). 'Korean' lespedeza flowers are borne at the end of the branch, 'Common' flowers are borne all along the stem.
Lespedezas are drought-resistant, warm-weather plants. The hay contains less moisture when cut than alfalfa or clover, and can often be removed from the field after 1 day (Wheeler 1950). McKee and Pieters (1937) stated that only one species, L. striata, has been long known to agriculture.
Many cultivars of lespedeza exist. Probably the most extensively grown cvs. are: 'Kobe', 'Teen. 76', 'Harbin', 'Rowan', 'Summit', and 'Iowa Six' (Henson and Cope 1969). Seed production is limited to the southern part of the lespedeza region.
If seed is to be produced, one very early cutting of hay may be removed first, then 100 to 400 pounds of seed are harvested although as much as 1,500 pounds have been harvested (McKee 1940). If grown only for hay, about 1.5 tons per acre are harvested.
Inflorescence:
The flowers of the lespedezas are of two types: petaliferous (or chasmogamous) and apetalous (or cleistogamous). In the latter, the petals never unfold, so the flower has the appearance of remaining in the bud stage and in which only self-fertilization takes place (Pieters 1934). This characteristic, first noted by Torrey and Gray (1840, pp. 366 - 369), has been studied by various workers. In each type of flower, the ovary has only one ovule. The petaliferous flower is similar to the pea flower - small (l/4 to l/2 inch) with blue to purple petals. The flowers are conspicuous in the shrubby species (fig. 122) but are inconspicuous in most of the herbaceous perennials or annuals (McKee 1948). The apetalous flowers are all inconspicuous.
Hanson (1953a) stated that anthesis or opening of the petaliferous flower occurred from 7 to 10 a.m. The flower is open most of the day, closes before night, and generally does not reopen. In these flowers, the filaments of the nine stamens are fused throughout most of their length. The style extends beyond the anthers, permitting cross-pollination. In the apetalous flowers, the style is J-shaped (Clewell 1964), so that the stigma touches one or more anthers and selfing can occur. Hanson (1953b) stated that the ovary is receptive to fertilization 1 or 2 days before anthesis.
Nectar is apparently secreted at the base of the corolla in the petaliferous flowers because bees visit them freely for both nectar and pollen (Mooers and Ogden 1935, Van Haltern 1936, Graetz 1951, Stitt 1946).
The reason for the development of the two kinds of flowers on lespedeza is unknown. Hanson (1943) concluded that temperature is a strong factor because most of the flowers were apetalous on plants grown at 70deg F, but were petaliferous on plants grown at 80deg. He was of the opinion that other factors also had an effect. There seems to be no information indicating that bees ever visit the apetalous flowers.
[gfx] FIGURE 122. - Flowering branch of bush lespedeza (Lespedeza bicolor).
Pollination Requirements:
Bohart (1960*) reviewed the pollination of the forage legumes and stated that the effect of insect pollinators on seed yields of annual lespedeza has apparently never been investigated. McKee and Hyland (1941) also indicated that there was no information on natural crossing in lespedeza. There is, however, some information on the influence of insect pollination on some of the species.
Stitt (1946) recorded 61.4 to 80.9 percent (average, 70.4 percent) cross-pollination in 'Sericea' which he attributed to the abundant activity of bees. Graetz (1951) showed that L. bicolor, L. japonica, and L. intermedia must be insect pollinated to produce a good seed crop. He stated that 'Sericea' has some flowers that depend on insects and others that self. Donnelly (1955) showed that offspring of 'Sericea' petaliferous flowers produced 25 percent more dry herbage and 40 percent more seeds than the self-pollinated apetalous flowers.
Cope (1966a, b) showed that some 'Sericea' flowers are cross- pollinated by bees and proposed a breeding program of several consecutive generations of inter-crossing for more productive plants. Although he did not go into detail about bee populations on the plants, he noted that 1963 was a poor seed production year for lespedeza, and, correspondingly, the percent crossing was the lowest in years. He recognized the need for bees and conjectured that the "natural bee population" was no longer sufficient to maintain the high level of crossing reported for 'Sericea' two decades ago. He did not consider supplementing the local population by bringing honey bee colonies into the area.
Pieters (1939b) stated that L. striata and L. stipulacea are believed to be self-pollinated. There the matter seems to have rested without further study.
The answer may lie in the fact that honey bees are not strongly attracted to these species (Pellett 1947*), and beekeepers make no effort to place their colonies near lespedeza fields. How the bees might act on the flowers under saturation distribution of colonies, such as is used in the pollination of alfalfa and some other crops, is unknown. The data indicate that floral visitation could be obtained on annual lespedezas if this were sufficiently desired. A study of the beneficial effect of bees on seed production of this crop would be most interesting and is needed.
Pollinators:
Graetz (1951) gave credit to the honey bees for setting the seed obtained in his test on L. bicolor, japonica, and intermedia, but noted that when the honey bees were moved away bumble bees freely visited the flowers. Mooers and Ogden (1935) stated that bees (presumably honey bees) visited the flowers of 'Sericea' for nectar. Cope (1966a, b) referred to the "bees" and the "natural bee population," possibly referring to wild bees on 'Sericea'. Stitt (1946) spoke of "natural crossing" and of usually abundant bees on 'Sericea'. Van Haltern (1936) stated that "bees" visited 'Sericea', L. bicolor, and L. virginica (L.) Britt., and, because he was writing in a beekeeping journal, he doubtless was referring to honey bees.
Beekeepers have generally observed that the lespedezas are scant producers of surplus honey. 'Korean' is rated as the best of the major species, L. bicolor and L. cyrtobotray Miq. are always attractive, although not grown on a large scale anywhere, and 'Kobe' and 'Sericea' are visited at times. Abernathy (1937) stated that lespedeza honey comes largely from 'Korean' with possibly a small amount from 'Common'. Derrenbacker (1936) concluded that bees get little honey from 'Korean'. Pellett (1939, 1952), Taylor (1935), Underhill (1946), and Watson (1938) considered lespedeza only a minor honey plant. Big differences were frequently observed in the populations of the bees on the crop. These differences were associated largely with climate, but location also seemed to be involved.
The evidence indicates that if heavy populations of bees were desired on the commercial lespedezas for pollination purposes they could probably be obtained if honey bee colonies were concentrated in or around the fields. However, the beekeeper would not be compensated for such action in honey storage by the colonies.
Pollination Recommendations and Practices:
The only recommendation for the use of honey bees on lespedeza was by Graetz (1951) who recommended a minimum of one colony per acre in connection with L. bicolor, japonica, and intermedia. Because the perennials appeared to be more attractive species to bees than 'Sericea', it would appear that if honey bees were used on 'Sericea' a higher concentration would be desired. The specific need or value, if any, of bees on 'Common' and 'Koreant lespedezas should be explored.
LITERATURE CITED:
ABERNATHY, E.
1937. LESPEDEZA FOR HONEY. Amer. Bee Jour. 77: 333.CLEWELL, A. F.
1964. THE BIOLOGY OF THE COMMON NATIVE LESPEDEZAS IN SOUTHERN INDIANA. Brittonia 16(2): 208 - 219.COPE, W. A.
1966a. CROSS-POLLINATION IN SERICEA LESPEDEZA. Crop Sci. 6: 469-470.______ 1966b. GROWTH RATE AND YIELD IN SERICEA LESPEDEZA IN RELATION TO SEED SIZE AND OUTCROSSING. Crop Sci. 6: 566.
DERRENBACKER, F., JR.
1936. A REPORT ON LESPEDEZA. Amer. Bee Jour. 76: 402.DONNELLY, E. D.
1955. THE EFFECTS OF OUTCROSSING ON FORAGE AND SEED YIELDS IN SERICEA LESPEDEZA, L. CUNEATA. Agron. Jour. 47: 466 - 467.ELROD, J. M.
1954. THE ANNUAL LESPEDEZAS. Ga. Agr. Expt. Sta Press Bul. 651, 2 pp.ESSARY, S. H.
1921. LESPEDEZA (JAPAN CLOVER). Tenn. Agr. Expt. Sta. Bul. 123, 28 pp.GRAETZ, K. E.
1951. SHRUB LESPEDEZA REQUIRES INSECT POLLINATION. Soil Conserv. 16: 224-226.HALTERN, F. VAN.
1936. LESPEDEZA AS A HONEY PLANT. Amer. Bee Jour. 76: 546.HANSON, C. H.
1943. CLEISTOGAMY AND THE DEVELOPMENT OF THE EMBRYO SAC IN LESPEDEZA STIPULACEA. Jour. Agr. Res. 67: 265 - 272.HANSON, C. H.
1953a. LESPEDEZA STIPULACEA STAMEN MORPHOLOGY, MEIOSIS, MICROGAMETOGENESIS, AND FERTILIZATION. Agron. Jour. 45: 200 - 203.______ 1953b. CONTROLLED HYBRIDIZATION IN LESPEDEZA STIPULACEA. Agron. Jour. 45:. 333.
HENSON, P. R., and COPE, W. A.
1969. ANNUAL LESPEDEZAS CULTURE AND USE. U.S. Dept. Agr. Farmers' Bul. 2113, 16 pp.KINNEY, E. J., and KENNEY, R.
1925. LESPEDEZA IN KENTUCKY. Ky. Agr. Ext. Sen. Cir. 179, 15 pp.McKEE, R.
1940. LESPEDEZA CULTURE AND UTILIZATION. U.S. Dept. Agr. Farmers' Bul. 1852, 14 pp.______ 1948. THE LEGUMES OF MANY USES. U.S. Dept. Agr. Yearbook 1948: 701 - 726.
______and HYLAND, H. L.
1941. APETALOUS AND PETALIFEROUS FLOWERS IN LESPEDEZA. Amer. Soc. Agron. Jour. 33: 811-815.______and PIETERS, A. J.
1937. MISCELLANEOUS FORAGE AND COVER CROP LEGUMES. U.S. Dept. Agr. Yearbook 1937: 999 - 1031.MOOERS, C. A., and OGDEN, H. P.
1935. LESPEDEZA SERICEA. Tenn. Agr. Expt. Sta. Bul. 154, 19 pp.PELLETT F. C.
1939. FROM OUR HONEY PLANT GARDENS: BIRDSFOOT TREFOIL, PHACELIA, LESPEDEZA, CLEOME. Amer. Bee Jour. 79: 386.PELLETT, M. A.
1952. FROM THE HONEY PLANT TEST GARDENS. Amer. Bee dour. 92: 247.PIETERS, A. J.
1934. THE LITTLE BOOK OF LESPEDEZA. 92 pp. Colonial Press, Washington.______ 1939a. LESPEDEZA SERICEA AND OTHER PERENNIAL LESPEDEZAS FOR FORAGE AND SOIL CONSERVATION. U.S. Dept. Agr. Cir. 534, 44 pp.
______ 1939b. THE ANNUAL LESPEDEZAS AS FORAGE AND SOIL-CONSERVING CROPS. U.S. Dept. Agr. Cir. 536, 55 pp.
STITT, R. E.
1946. NATURAL CROSSING AND SEGREGATION IN SERICEA LESPEDEZA, LESPEDEZA CUNEATA (DUMONT) G. DON. Amer. Soc. Agron. Jour. 38: 1 - 5.TAYLOR, D. W.
1935. A FURTHER REPORT FROM VIRGINIA ON LESPEDEZA. Amer. Bee Jour. 75: 572.TORREY, J., and GRAY, A.
1840. FLORA OF NORTH AMERICA. V. 1, 711 pp. Wiley and Putnam, New York.UNDERHILL, R.
1946. LESPEDEZA IN ARKANSAS. Amer. Bee Jour. 84: 406.WATSON, W. E.
1938. LESPEDEZA AGAIN. Amer. Bee Jour. 78: 224.WHEELER, W. A.
1950. FORAGE AND PASTURE CROPS. 752 pp. D. van Norstrand Co., Inc., New York.
