Milkweed Cardenolides and Their Comparative Processing by Monarch Butterflies (Danaus plexippus L.)

  • C. N. Roeske
  • J. N. Seiber
  • L. P. Brower
  • C. M. Moffitt
Part of the Recent Advances in Phytochemistry book series (RBIO, volume 10)


The milkweed family (Asclepiadaceae) comprises some 200 genera and 2500 species of perennial shrubs, herbs and vines distributed throughout the tropics and extending to temperate areas of the world. They include some highly prized ornamentals and economically significant weeds, and are generally characterized to the layman by the milky latex they exude when a leaf or other organ is ruptured. Chemical interest in the milkweeds has been stimulated by the use of some plants in medicinal preparations to treat cancers, tumors, and warts (Refs. in 54), as emetics, to treat bronchitis (Refs. in 64), and as a source of digitalislike therapeutic agents (Refs. in 44). They are also known for their poisonous nature, which has found advantageous use in the preparation of arrow poisons, and also causes occasional but extensive poisoning episodes among grazing sheep and cattle in milkweed-infested rangelands52,58.


Cardiac Glycoside Storage Efficiency Monarch Butterfly Adult Butterfly Amherst College 
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  1. 1.
    Abisch, E. and T. Reichstein. 1962. Chemical orientation investigation of some Asclepiadaceae and Periplocaceae. Helv. Chim. Acta, 45:2090.Google Scholar
  2. 2.
    Bauer, S., L. Masler, O. Bauerova and D. Sikl. 1961. Uzarigenin and desglucouzarin from Asclepias syriaca L. Experientia, 17:15.PubMedGoogle Scholar
  3. 3.
    Borison, H.L. and S.C. Wang. 1953. Physiology and pharmacology of vomiting. Pharmac. Rev., 5:193.Google Scholar
  4. 4.
    Brower, L.P. 1969. Ecological chemistry. Scient. Amer., 220:22.Google Scholar
  5. 5.
    Brower, L.P. 1970. Plant poisons in a terrestrial food chain and implications for mimicry theory. In: Biochemical Coevolution, Proceedings of the Twenty-Ninth Annual Biology Colloquim, 1968. K.L. Chambers (ed), Oregon State University Press, Corvallis, Oregon, p. 69.Google Scholar
  6. 6.
    Brower, L.P., and J.V.Z. Brower. 1964. Birds, butterflies and plant poisons:a study in ecological chemistry. Zoologica, 49:137.Google Scholar
  7. 7.
    Brower, L.P., J.V.Z. Brower and J.M. Corvino. 1967. Plant poisons in a terrestrial food chain. Proc. Nat. Acad. Sci., 57:893.PubMedGoogle Scholar
  8. 8.
    Brower, L.P., M. Edmunds and C.M. Moffitt. 1975. Cardenolide content and palatability of a population of Danaus chrysippus butterflies from West Africa. J. Ent. (A), 49:183.Google Scholar
  9. 9.
    Brower, L.P. and S.C. Glazier. 1975. Localization of heart poisons in the monarch butterfly. Science, 188:19.PubMedGoogle Scholar
  10. 10.
    Brower, L.P., P.B. McEvoy, K.L. Williamson and M.A. Flannery. 1972. Variation in cardiac glycoside content of monarch butterflies from natural populations in eastern North America. Science, 177:426.PubMedGoogle Scholar
  11. 11.
    Brower, L.P. and C.M. Moffitt. 1974. Palatability dynamics of cardenolides in the monarch butterfly. Nature, 249:280.PubMedGoogle Scholar
  12. 12.
    Brower, L.P., W.N. Ryerson, L.L. Coppinger and S.C. Glazier. 1968. Ecological chemistry and the palatability spectrum. Science, 161:1349.PubMedGoogle Scholar
  13. 13.
    Brüschweiler, F., K. Stockel and T. Reichstein. 1969a. Calotropis-glycosides, presumed partial structure. Helv. Chim. Acta, 52:2276.PubMedGoogle Scholar
  14. 14.
    Brüschweiler, F., W. Stocklin, K. Stockel and T. Reichstein. 1969b. Glycosides of Calotropis procera R. Br. Helv. Chim. Acta, 52:2086.PubMedGoogle Scholar
  15. 15.
    Carman, R.M., R.G. Coombe and T.R. Watson. 1964. The cardiac glycosides of Gomphocarpus fruticosus (R. Br.) IV. The nuclear magnetic resonance spectrum of gomphoside. Aust. J. Chem., 17:573.Google Scholar
  16. 16.
    Chen, K.K., E.B. Robbins and H. Worth. 1938. The significance of sugar component in the molecule of cardiac glycosides. J. Am. Pharm. Ass., 27:189.Google Scholar
  17. 17.
    Chernobai, V.T. 1957. Cardiac glycosides of Gomphocarpus fruticosus. I. Glycosides of the seed. Med. Prom. S.S.S.R., 11: 38. [Chem. Abstr., 52:8465a]Google Scholar
  18. 18.
    Chernobai, V.T. and N.F. Komissarenko. 1971. Cardenolides from Gomphocarpus fruticosus and partial synthesis of uzarigenin glycosides. Khim. Prir. Soedin., 7:445. [Chem. Abstr., 75:141103w]Google Scholar
  19. 19.
    Coombe, R.G. and T.R. Watson. 1962. Structure of β-anhydrogomphogenin. Chem. and Ind., 1962:1724.Google Scholar
  20. 20.
    Coombe, R.G. and T.R. Watson. 1964. The cardiac glycosides of Gomphocarpus fruticosus R. Br. III. Gomphoside. Aust. J. Chem., 17:92.Google Scholar
  21. 21.
    Crout, D.H.G., R.F. Curtis, C.H. Hassall and T.L. Jones. 1963. The cardiac glycosides of Calotropis procera. Tetrahedron Lett., 1963:63.Google Scholar
  22. 22.
    Crout, D.H.G., C.H. Hassall and T.L. Jones. 1964. Cardenolides. Part VI. Uscharidin, calotropin, and calotoxin. J. Chem. Soc., 1964:2187.Google Scholar
  23. 23.
    Dethier, V.G. 1970. Chemical interactions between plants and insects. In: Chemical Ecology, E. Sondheimer and J.B. Simeone (eds), Academic Press, New York, Chapter 5.Google Scholar
  24. 24.
    Dixon, W.J. and F.J. Massey, Jr., 1957. Introduction to Statistical Analysis, McGraw-Hill, New York.Google Scholar
  25. 25.
    Duffey, S.S. 1970. Cardiac glycosides and distaste-fulness: some observations on the palatability spectrum of butterflies. Science, 169: 78.PubMedGoogle Scholar
  26. 26.
    Duffey, S.S. and G.G.E. Scudder. 1972. Cardiac glycosides in North American Asclepiadaceae, a basis for unpalatability in brightly coloured Hemiptera and Coleoptera. J. Insect Physiol., 18:63.Google Scholar
  27. 27.
    Duffey, S.S. and G.G.E. Scudder. 1974. Cardiac glycosides in Oncopeltus fasciatus (Dallas) (Hemiptera: Lygaeidae). I. The uptake and distribution of natural cardenolides in the body. Can. J. Zool., 52:283.Google Scholar
  28. 28.
    Eisner, T. 1970. Chemical defense against predation in arthropods. In: Chemical Ecology, E. Sondheimer and J. B. Simeone (eds), Academic Press, New York, Chapter 8.Google Scholar
  29. 29.
    Erickson, J.M. 1973. The utilization of various Asclepias species by larvae of the monarch butterfly, Danaus plexippus. Psyche, 80:230.Google Scholar
  30. 30.
    Evans, F.J. and P.S. Cowley. 1972. Cardenolides and spirostanols in Digitalis purpurea at various stages of development. Phytochem., 11: 2971.Google Scholar
  31. 31.
    Feeny, P. 1975. Biochemical coevolution between plants and their insect herbivores. In: Coevolution of Animals and Plants, L.E. Gilbert and P.H. Raven (eds), University of Texas Press, Austin, p. 3.Google Scholar
  32. 32.
    Feir, D. and J. Suen. 1971. Cardenolides in the milkweed plant and feeding by the milkweed bug. Ann. Entomol. Soc. Am., 64:1173.Google Scholar
  33. 33.
    Fieser, L.F. and M. Fieser. 1959. Steroids, Reinhold, New York, Chapter 20.Google Scholar
  34. 34.
    Fraenkel, G.S. 1959. The raison d’etre of secondary plant substances. Science, 129:1466.PubMedGoogle Scholar
  35. 35.
    Gaitonde, B.B. and S.N. Joglekar. 1975. Role of catecholamines in the central mechanism of emetic response induced by peruvoside and ouabain in cats. Br. J. Pharmacol., 54:157.PubMedGoogle Scholar
  36. 36.
    Hassall, C.H. and K. Reyle. 1959. Cardenolides. Part III. Constitution of calotropagenin. J. Chem. Soc., 1959:85.Google Scholar
  37. 37.
    Hendry, L.B., J.K. Wichmann, D.M. Hindenlang, R.O. Mumma and M.E. Anderson. 1975. Evidence for origin of insect sex pheromones: presence in food plants. Science, 188:59.PubMedGoogle Scholar
  38. 38.
    Hesse, G., H. Fasold and W. Geiger. 1959. African arrow poisons. X. Calotropin from uscharidin. Liebigs Ann. Chem., 625:157.Google Scholar
  39. 39.
    Hesse, G. and H.W. Gampp. 1952. African arrow poisons. VI. The heterocyclic part of uscharin. Chem. Ber., 85: 933.Google Scholar
  40. 40.
    Hesse, G., L.J. Heuser, E. Hutz and F. Reicheneder. 1950. African arrow poisons. V. Relationships between the most important poisons of Catotropis procera. Liebigs Ann. Chem., 566:130.Google Scholar
  41. 41.
    Hesse, G. and G. Lettenbauer. 1957. A second sulfur-containing compound from the milky-juice of Catotropis procera. Angew. Chem., 69:392.Google Scholar
  42. 42.
    Hesse, G. and G. Ludwig. 1960. African arrow poisons. XIV. Voruscharin, a second sulfur-containing heart poison from Catotropis procera L. Liebigs Ann. Chem., 632: 158.Google Scholar
  43. 43.
    Hesse, G. and K. Mix. 1959. African arrow poisons. IX. Structure and partial synthesis of uscharin. Liebigs Ann. Chem., 625:146.Google Scholar
  44. 44.
    Hesse, G. and F. Reicheneder. 1936. African arrow poison calotropin. I. Liebigs Ann. Chem., 526: 252.Google Scholar
  45. 45.
    Hesse, G., F. Reicheneder and H. Eysenbach. 1939. African arrow poisons. II. Heart poisons in Catotropis latex. Liebigs Ann. Chem., 537:67.Google Scholar
  46. 46.
    Hoch, J.H. 1961. A Survey of Cardiac Glycosides and Genins, Univ. of South Carolina Press, Charleston, South Carolina.Google Scholar
  47. 47.
    Hunger, A. and T. Reichstein. 1952a. Frugoside, a second crystallized glycoside from the seeds of Gomphocarpus fructicosus. Helv. Chim. Acta, 35:429.Google Scholar
  48. 48.
    Hunger, A. and T. Reichstein. 1952b. The constitution of gofruside and frugoside. Helv. Chim. Acta, 35: 1073.Google Scholar
  49. 49.
    Keller, M. and T. Reichstein. 1949. Gofruside, a crystalline glycoside from the seeds of Gomphocarpus fructicosus (L) R. Br. Helv. Chim. Acta, 32:1607.Google Scholar
  50. 50.
    Kelly, R.B., E.G. Daniels and L.B. Spaulding. 1965. Cytotoxicity of cardiac principles. J. Med. Chem., 8:547.PubMedGoogle Scholar
  51. 51.
    Jaggi, K., H. Kaufmann, W. Stocklin and T. Reichstein. 1967. Glycosides of Asclepias swynnertonii S. Moore, roots. Helv. Chem. Acta, 50: 2457.Google Scholar
  52. 52.
    Kingsbury, J.M. 1964. Poisonous Plants of the United States and Canada, Prentice-Hall, Englewood Cliffs, N.J., p. 269.Google Scholar
  53. 53.
    Krieger, R.I., P.P. Feeny and C.F. Wilkinson. 1971. Detoxication enzymes in the guts of caterpillars: an evolutionary answer to plant defenses? Science, 172:579.PubMedGoogle Scholar
  54. 54.
    Kupchan, S.M., J.R. Knox, J.E. Kelsey and J.A.S. Renauld. 1964. Calotropin, a cytotoxic principle isolated from Asclepias curassavica L. Science, 146:1685.PubMedGoogle Scholar
  55. 55.
    Lardon, A., K. Stockel and T. Reichstein. 1969. Gomphogenin—partial synthesis and structure of calotropagenin. Helv. Chem. Acta, 52:1940.Google Scholar
  56. 56.
    Lardon, A., K. Stockel and T. Reichstein. 1970. Partial synthesis of 2α, 3β, 19-triacetoxy-14β-hydroxy-5α-card-20(22)-enolide. Additional proof of calotropagenin structure. Helv. Chim. Acta, 53:167.Google Scholar
  57. 57.
    Mahran, G.H., M.M. Rizkallah and A.H. Saber. 1971. A phytochemical study of Calotropis procera (Ait) R. Br. growing in Egypt. Bull. Fac. Pharm. Cario Univ., 10:1.Google Scholar
  58. 58.
    Marsh, C.D. and A.B. Clawson. 1924. The woolly-pod milkweed (Asclepias eriocarpa) as a poisonous plant. United States Department of Agriculture Bulletin. No. 1212.Google Scholar
  59. 59.
    Masler, L., S. Bauer, O. Bauerova, and D. Sikl. 1962a. Cardiac glycosides from Asclepias syriaca. I. Isolation of cardiac active steroids. Collect. Czech. Chem. Commun., 27:872.Google Scholar
  60. 60.
    Masler, L., S. Bauer, O. Bauerova and D. Sikl. 1962b. Cardiac glycosides from Asclepias syriaca. II. Structure of syriogenin and its glycosides. Collect. Czech. Chem. Commun., 27:895.Google Scholar
  61. 61.
    Mathavan, S. and R. Bhaskaran. 1975. Food selection and utilization in a Danaid butterfly. Oecologia, 18:55.Google Scholar
  62. 62.
    Mitsuhashi, H., K. Hayashi and K. Tomimoto. 1970. Studies on the constituents of the Asclepiadaceae plants. XXVIII. Components of Asclepias syriaca L. Chem. Pharm. Bull., 18:828.Google Scholar
  63. 63.
    Mitsuhashi, H. and M. Kurumi. 1968. Constituents of Asclepiadaceae plants. XXIII. Components of Gomphocarpus fruticosus. Shoyakagaku Zasshi, 22: 86. [Chem. Abstr., 71:88459f]Google Scholar
  64. 64.
    Mittal, O.P., Ch. Tamm and T. Reichstein. 1962. Glycosides of Pergularia extensa (Jacq) N.E. Br. Helv. Chem. Acta, 45:907.Google Scholar
  65. 65.
    Moe, G.K. and A.E. Farah. 1970. Digitalis and allied cardiac glycosides. In: The Pharmacological Basis of Therapeutics, L. S. Goodman and A. Gilman (eds), Macmillan, New York. Chapter 31.Google Scholar
  66. 66.
    Muller, C. H. 1970. The role of allelopathy in the evolution of vegetation. In: Biochemical Co-evolution, Proceedings of the Twenty-Ninth Annual Biology Colloquium, 1968. K.L. Chambers (ed), Oregon State University Press, Corvallis, Oregon, p. 13.Google Scholar
  67. 67.
    Nascimento, J.M. 1964. Cardenolides in leaves of Asclepias glaucophylla. Rev. Port. Quim., 6: 97. [Chem. Abstr., 64:5549f]Google Scholar
  68. 68.
    Nascimento, Jr., J.M., Ch. Tamm, H. Jager and T. Reichstein. 1964. Glycosides of Asclepias glaucophylla Schlechter roots. Helv. Chem. Acta, 47:1775.Google Scholar
  69. 69.
    Neher, R. 1969. TLC of steroids and related compounds. In: Thin-Layer Chromatography, A Laboratory Handbook, E. Stahl (ed), Springer-Verlag, New York, p. 311.Google Scholar
  70. 70.
    Parsons, J.A. 1965. A digitalis-like toxin in the monarch butterfly, Danaus plexippus L. J. Physiol., 178:290.PubMedGoogle Scholar
  71. 71.
    Parsons, J.A. and R.J. Summers. 1971. Cat assay for the emetic action of digitalis and related glycosides (digitoxin, digoxin, lanatoside C, ouabain, and calactin). Br. J. Pharmacol., 42:143.PubMedGoogle Scholar
  72. 72.
    Petricic, J. 1967. Cardenolides of some species of the genus Asclepias. Farm. Glas., 23:3. [Chem. Abstr., 67:8686g]Google Scholar
  73. 73.
    Petricic, J. 1966a. Desglucouzarin, the principal cardenolide glycoside of Asclepias mellodora St.Hil. Naturwissenschaften, 53:332.PubMedGoogle Scholar
  74. 74.
    Petricic, J. 1966b. Cardenolides from the roots of Ascelpias tuberosa. Arch. Pharm., 299:1007. [Chem. Abstr., 66:76274a]Google Scholar
  75. 75.
    Pliske, T.E. and T. Eisner. 1969. Sex pheromone of the queen butterfly: biology. Science, 164:1170.PubMedGoogle Scholar
  76. 76.
    Rabitzsch, G. and U. Tambor. 1969. Method for the quantitative determination of cardiac glycosides and genins of the cardenolide type with 2,4,2′,4′-tetranitrodiphenyl. Pharmazie, 24:262.PubMedGoogle Scholar
  77. 77.
    Rajagopalan, S., Ch. Tamm and T. Reichstein. 1955. The glycosides of seeds of Calotropis procera R. Br. Helv. Chem. Acta, 38:1809.Google Scholar
  78. 78.
    Reichstein, T. 1967a. Cardenolide-and pregnanglycosides. Naturwissenschaften, 54:53.Google Scholar
  79. 79.
    Reichstein, T. 1967b. Cardiac glycosides as defensive substances in insects. Naturwiss. Rundsch., 20: 499.Google Scholar
  80. 80.
    Reichstein, T., J. von Euw, J.A. Parsons, and M. Rothschild. 1968. Heart poisons in the monarch butterfly. Science, 161:861.PubMedGoogle Scholar
  81. 81.
    Repke, K. 1963, Metabolism of cardiac glycosides. In: New aspects of cardiac glycosides, Proceedings of the first international pharmacological meeting, W. Wilbrandt and P. Lindgren (eds), Macmillan, New York, Volume 3, p. 47.Google Scholar
  82. 82.
    Rice, E.L. 1974. Allelopathy. Academic Press, New York.Google Scholar
  83. 83.
    Robbins, W.E., J.N. Kaplanis, J.A. Svoboda and M.J. Thompson. 1971. Steroid metabolism in insects. In: Annual Review of Entomology. R.F. Smith and T.E. Mittler (eds), Palo Alto, Calif., Volume 16, p. 53.Google Scholar
  84. 84.
    Robinson, T. 1974. Metabolism and function of alkaloids in plants. Science, 184:430.PubMedGoogle Scholar
  85. 85.
    Rothschild, M. 1972a. Secondary plant substances and warning colouration in insects. In: Insect/Plant Relationships, Symposia of the Royal Entomological Society of London, H.F. van Emden (ed), Blackwell Scientific Publications, Oxford, p. 59.Google Scholar
  86. 86.
    Rothschild, M. 1972b. Some observations on the relationship between plants, toxic insects, and birds. In: Phytochemical Ecology, J.B. Harborne (ed), Academic Press, New York. Chapter 1.Google Scholar
  87. 87.
    Rothschild, M., J. von Euw and T. Reichstein. 1970. Cardiac glycosides in the oleander aphid, Aphis nerii. J. Insect Physiol., 16:1141.PubMedGoogle Scholar
  88. 88.
    Rothschild, M., J. von Euw, T. Reichstein, D.A.S. Smith, and J. Pierre. 1975. Cardenolide storage in Danaus chrysippus (L.) with additional notes on D. plexippus. Proc. R. Soc. Lond. B., 190:1.Google Scholar
  89. 89.
    Sawlewicz, L., E. Weiss and T. Reichstein. 1967. Cardenolide and pregnanglycosides of Asclepias lilacina Weimarck roots. I. Isolation. Helv. Chim. Acta, 50:504.Google Scholar
  90. 90.
    Schildknecht, H. 1971. Evolutionary peaks in the defensive chemistry of insects. Endeavor, 30:136.Google Scholar
  91. 91.
    Schoonhoven, L.M. 1972. Secondary plant substances and insects. In: Structural and Functional Aspects of Phytochemistry, Recent Advances in Phytochemistry, V.C. Runeckles and T.C. Tso (eds), Academic Press, New York; Volume 5, p. 197.Google Scholar
  92. 92.
    Scudder, G.G.E. and S.S. Duffey. 1972. Cardiac glycosides in the Lygaeinae (Hemiptera:Lygaeidae). Can. J. Zool, 50:35.Google Scholar
  93. 93.
    Singh, B. and R.P. Rastogi. 1969. Chemical investigation of Asclepias curassavica Linn. Indian J. Chem., 7:1105.Google Scholar
  94. 94.
    Singh, B. and R.P. Rastogi. 1970. Cardenolides—glycosides and genins. Phytochem., 9:315.Google Scholar
  95. 95.
    Singh, B. and R.P. Rastogi. 1972. Structure of asclepin and some observations on the nmr spectra of Calotropis glycosides. Phytochem., 11:757.Google Scholar
  96. 96.
    Seiber, J.N., J.M. Benson, C.N. Roeske and L.P. Brower. 1975. Qualitative and quantitative aspects of milk weed cardenolide sequestering by monarch butterflies. Paper presented at 170th National Meeting of the American Chemical Society, Division of Pesticide Chemistry (Pest 103), Chicago, August.Google Scholar
  97. 97.
    Tamm, Ch. 1956. New developments in the field of glycosidal cardiac poisons—fundamentals and the aglycons. Fortschr. Chem. Org. Naturstoffe, 13: 137.Google Scholar
  98. 98.
    Tamm, Ch. 1957. New results from the field of glyco-sidic heart poisons; sugar and glycoside. Fortschr. Chem. Org. Naturstoffe, 14:71.Google Scholar
  99. 99.
    Tamm, Ch. 1963. The stereochemistry of the glycosides in relation to biological activity. In: New Aspects of Cardiac Glycosides, Proceedings of the first international pharmacological meeting, W. Wilbrandt and P. Lindgren (eds), Macmillan, New York, Volume 3, p. 11.Google Scholar
  100. 100.
    Tschesche, R., D. Forstmann and V.K.M. Rao. 1958. Cardenolide components of Asclepias curassavica L. Chem. Ber., 91: 1204.Google Scholar
  101. 101.
    Tschesche, R., G. Snatzke and G. Grimmer. 1959. Calotropagenin from Asclepias curassavica L. Naturwissenschaften, 46:263.Google Scholar
  102. 102.
    von Euw, J., L. Fishelson, J.A. Parsons, T. Reichstein, and M. Rothschild. 1967. Cardeno-lides (heart poisons) in a grasshopper feeding on milkweeds. Nature, 214:35.Google Scholar
  103. 103.
    Waldbauer, G.P. 1968. The consumption and utilization of food by insects. In: Advances in Insect Physiology, Volume 5, J.W.L. Beament, J.E. Treherne and V.B. Wigglesworth (eds), Academic Press, New York, p. 229.Google Scholar
  104. 104.
    Watson, T.R. 1966. The cardiac glycosides of Asclepias fruticosa. Colloq. Int. Centre Nat.Rech. Sci. No. 144:173.Google Scholar
  105. 105.
    Watson, T.R. and S.E. Wright. 1954. The Cardiac glycosides of Gomphocarpus fruticosus (R. Br.). Chem. and Ind., 1954: 1178.Google Scholar
  106. 106.
    Watson, T.R. and S.E. Wright. 1956. The cardiac glycosides of Gomphocarpus fruticosus R. Br. I. Afroside. Aust. J. Chem., 9, 497.Google Scholar
  107. 107.
    Watson, T.R. and S.E. Wright. 1957. The cardiac glycosides of Gomphocarpus fruticosus R. Br. II. Gomphoside. Aust. J. Chem., 10:79.Google Scholar
  108. 108.
    Whittaker, R.H. and P.P. Feeny. 1971. Allelochemics: chemical interactions between species. Science, 171:757.PubMedGoogle Scholar
  109. 109.
    Wood, D.L. 1970. Pheromones of bark beetles. In: Control of Insect Behaviour by Natural Products, D.L. Wood, R.M. Silverstein, and M. Nakajima (eds), Academic Press, New York, p. 301.Google Scholar
  110. 110.
    Woodson, Jr., R.E. 1941. The North American Asclepiadaceae. I. Perspective of the genera. Ann. Mo. Bot. Gard., 28:193.Google Scholar
  111. 111.
    Woodson, Jr., R.E. 1954. The North American species of Asclepias L. Ann. Mo. Bot. Gard., 41:1.Google Scholar

Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • C. N. Roeske
    • 1
  • J. N. Seiber
    • 1
  • L. P. Brower
    • 2
  • C. M. Moffitt
    • 2
  1. 1.Department of Environmental ToxicologyUniversity of CaliforniaDavisUSA
  2. 2.Department of BiologyAmherst CollegeAmherstUSA

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