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Friedman, W.E.  2017.  Insights into how the world turned green.  New Phytologist 215: 505-507. | pdf

Losada, J.M., J.B. Bachelier and W.E. Friedman.  2017.  Prolonged embryogenesis in Austrobaileya scandens (Austrobaileyaceae): its ecological and evolutionary significance.  New Phytologist 215: 851-864. | pdf


Pirone-Davies, C., N. Prior, P. von Aderkas, D. Smith, D. Hardie, W.E. Friedman, and S. Mathews. Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production. Annals of Botany. | pdf

Schoonderwoerd, K. and W.E. Friedman. 2016. Zygotic dormancy underlies prolonged seed development in Franklinia alatamaha (Theaceae): a most unusual case of reproductive phenology in angiosperms. Botanical Journal of the Linnean Society. | pdf

Friedman, W.E., M.S. Dosmann, T.M. Boland, D.E. Boufford, M.J. Donoghue, A. Gapinski, L. Hufford, P.W. Meyer and D.H. Pfister.  2016.  Developing an exemplary collection:  a vision for the next century at the Arnold Arboretum of Harvard University.  Arnoldia 73(3): 2-18. | pdf


Povilus, R.A., Losada, J.M. and W.E. Friedman. 2015. Floral biology and ovule and seed ontogeny of Nymphaea thermarum, a water lily at the brink of extinction with potential as a model system for basal angiosperms. Annals of Botany 115, 211-226. | pdf

Friedman, W.E. 2015. Development and evolution of the female gametophyte and fertilization process in Welwitschia mirabilis (Welwitschiaceae). American Journal of Botany 102, 312-324. | pdf

Friedman, W.E. 2015. Evolving words and the egg-bearing tubes of Welwitschia (Welwitschiaceae). American Journal of Botany 102, 176-179. | pdf


Losada, J., Herrero, M., Hormaza, J. and W.E. Friedman. 2014. Arabinogalactan proteins mark stigmatic receptivity in the protogynous flowers of Magnolia virginiana (Magnoliaceae). American Journal of Botany 101, 1963-1975. | pdf


Wu, C.-C., Diggle, P.K. and W.E. Friedman. 2013. Kin recognition within a seed and the effect of genetic relatedness of an endosperm to its compatriot embryo on maize seed development. Proceedings of the National Academy of Sciences of the United States 110, 2217-2222. | pdf

Friedman, W.E. 2013. Plant science. One genome, two ontogenies. Science 339, 1045. | pdf

Bachelier, J.B. and W.E. Friedman. 2013. Seed development in Trimenia (Trimeniaceae) and its bearing on the evolution of embryo-nourishing strategies in early flowering plant lineages. American Journal of Botany 100, 906-915. | pdf


Friedman, W.E., Bachelier, J. & Hormaza, J. 2012. Embryology in Trithuria submersa (Hydatellaceae) and relationships between embryo, endosperm, and perisperm in early-diverging flowering plants. American Journal of Botany 99, 1083. | pdf


Friedman, W.E. & Diggle, P.K. 2011. Charles Darwin and the origins of plant evolutionary developmental biology. Plant Cell 23, 1194-1207. | pdf

Bachelier, J.B. and W.E. Friedman. 2011. Female gamete competition in an ancient angiosperm lineage. Proceedings of the National Academy of Sciences of the United States 108, 12360. | pdf

Ishikawa, M., et al. 2011. Physcomitrella Cyclin-dependent Kinase A links cell cycle reactivation to other cellular changes during reprogramming of leaf cells. Plant Cell 23, 2924-2938. | pdf

Friedman, W.E. 2011. Plant genomics: Homoplasy heaven in a lycophyte genome. Current Biology 21, R554-R556. | pdf


Madrid, E.N. and W.E. Friedman. 2010. Female gametophyte and early seed development in Peperomia (Piperaceae). American Journal of Botany 97: 1-14. | pdf


Friedman, W.E. 2009. Auxin at the evo-devo intersection. Science 324: 1652-1653 (invited perspective). | pdf

Winther, J.L. and W.E. Friedman. 2009. Phylogenetic affinity of arbuscular mycorrhizal symbionts in Psilotum nudum. Journal of Plant Research 122: 485-496. | pdf

Madrid, E.N. and W.E. Friedman. 2009. The developmental basis of an evolutionary diversification of female gametophyte structure in Piper and Piperaceae. Annuals of Botany 103: 869-884. | pdf | commentary

Friedman, W.E. 2009. Evolution pioneers: Celebrating Lamarck at 200, Darwin 215. Nature 461, 167. | pdf

Friedman, W.E. and K.C. Ryerson. 2009. Reconstructing the ancestral female gametophyte of angiosperms: insights from Amborella and other ancient lineages of flowering plants. American Journal of Botany 96: 129-143. | pdf

Friedman, W.E. 2009. The meaning of Darwin’s “abominable mystery.” American Journal of Botany 96: 5-21. | pdf


Holloway, S.J. and W.E. Friedman. 2008. Embryological features of Tofieldia glutinosa and their bearing on the early diversification of monocotyledonous plants. Annals of Botany 102: 167-182. | pdf

Friedman, W.E., S.C.H. Barrett, P.K. Diggle, V.F. Irish and L. Hufford. 2008. Whither plant evo-devo? Investigating the evolution of plant form: conceptual integration from the molecular to the ecological. New Phytologist 178: 468-471. | pdf

Friedman, W.E. 2008. Hydatellaceae are water lilies with gymnospermous tendencies. Nature 453: 94-97. | pdf

Madrid, E.N. and W.E. Friedman. 2008. Female gametophyte development in Aristolochia labiata Willd. (Aristolochiaceae). Botanical Journal of the Linnean Society, 158: 19-29. | pdf

Friedman, W.E., E.N. Madrid, and J.H. Williams. 2008. Origin of the fittest and survival of the fittest: relating female gametophyte development to endosperm genetics. International Journal of Plant Sciences 169: 79-92. | pdf

Winther J.L. and W.E. Friedman. 2008. Arbuscular mycorrhizal associations in Lycopodiaceae. New Phytologist 177: 790-801. | pdf | commentary


Winther, J.L. and W.E. Friedman. 2007. Arbuscular mycorrhizal symbionts in Botrychium (Ophioglossaceae). American Journal of Botany 94: 1248-1255. | pdf


Friedman, W.E. 2006. Sex among the flowers. Natural History 115 (9): 48-53. | pdf

Friedman, W.E. 2006. Embryological evidence for developmental lability during early angiosperm evolution. Nature 441: 337-340. | pdf


Friedman, W.E., and J.H. Williams. 2004. Developmental evolution of the sexual process in ancient flowering plant lineages. Plant Cell 16: S119-S132. | pdf

Friedman W.E., R.C. Moore and M.D. Purugganan. 2004. The evolution of plant development. American Journal of Botany 91: 1726-1741. | pdf

Williams, J.H., and W.E. Friedman. 2004. The four-celled female gametophyte of Illicium (Illiciaceae; Austrobaileyales): implications for understanding the origin and early evolution of monocots, eumagnoliids, and eudicots. American Journal of Botany 91: 332-351. | pdf


Friedman, W.E., W.N. Gallup and J.H. Williams. 2003. Female gametophyte development in Kadsura: implications for Schisandraceae, Austrobaileyales, and the early evolution of flowering plants. International Journal of Plant Sciences 164: S293-S305. | pdf

Friedman, W.E. and J.H. Williams. 2003. Modularity in the angiosperm female gametophyte and its bearing on the early evolution of endosperm in flowering plants. Evolution 57: 216-230. | pdf


Williams, J.H. and W.E. Friedman. 2002. Identification of diploid endosperm in an early angiosperm lineage. Nature 415: 522-526. | pdf

Hiscock, S.J., K. Hoedemaekers, W.E Friedman and H.G. Dickinson. 2002. The stigma surface and pollen-stigma interactions in Senecio squalidus L. (Asteraceae) following cross (compatible) and self (incompatible) pollinations. International Journal of Plant Sciences 163: 1-16. | pdf


Floyd, S.K. and W.E. Friedman. 2001. Developmental evolution of endosperm in basal angiosperms: evidence from Amborella (Amborellaceae), Nuphar (Nymphaeaceae), and Illicium (Illiciaceae). Plant Systematics and Evolution 228: 153-169. | pdf

Friedman, W.E. 2001. Comparative embryology of basal angiosperms. Current Opinion in Plant Biology 4: 14-20. | pdf

Friedman, W.E. 2001. Developmental and evolutionary hypotheses for the origin of double fertilization and endosperm. Comptes Rendus de l’Academie des Sciences 324: 559-567. | pdf

Friedman, W.E. and S.K. Floyd. 2001. The origin of flowering plants and their reproductive biology: a tale of two phylogenies. Evolution 55: 217-231. | pdf


Floyd, S.K. and W.E. Friedman. 2000. Evolution of endosperm developmental patterns among basal flowering plants. International Journal of Plant Sciences 161: S57-S81. | pdf

Friedman, W.E. and M.E. Cook. 2000. The origin and early evolution of tracheids in vascular plants: integration of paleobotanical and neobotanical data. Philosophical Transactions of the Royal Society London B 355: 857-868. | pdf


Floyd, S.K., V.T. Lerner and W.E. Friedman. 1999. A developmental and evolutionary analysis of embryology of Platanus (Platanaceae), a basal eudicot. American Journal of Botany 86: 1523-1537. | pdf

Williams, J.H., W.E. Friedman and M.L. Arnold. 1999. Developmental selection within the angiosperm style: Using gamete DNA to visualize interspecific pollen competition. Proceedings of the National Academy of Sciences 96: 9201-9206. | pdf

Friedman, W.E. 1999. Expression of the cell cycle in sperm of Arabidopsis: implications for understanding patterns of gametogenesis and fertilization in plants and other eukaryotes. Development 126: 1065-1075. | pdf


Friedman, W.E. and J.S. Carmichael. 1998. Heterochrony and developmental innovation: evolution of female gametophyte ontogeny in Gnetum. Evolution 52: 1016-1030. | pdf

Cook, M.E. and W.E. Friedman. 1998. Tracheid structure in a primitive extant plant provides an evolutionary link to earliest fossil tracheids. International Journal of Plant Sciences 159: 881-890. | pdf

Friedman, W.E. 1998. The evolution of double fertilization and endosperm: an “historical” perspective. Sexual Plant Reproduction 11: 6-16. | pdf


Friedman, W.E. and E.M. Gifford. 1997. Development of the male gametophyte of Ginkgo biloba: a window into the reproductive biology of early seed plants. In Botanical Society of Japan Special Volume, Ginkgo biloba. T. Hori, ed. Springer Verlag, Tokyo. | pdf


Friedman, W.E. 1996. Introduction to biology and evolution of the Gnetales. International Journal of Plant Sciences 157: S1-S2. | pdf

Friedman, W.E. and J.S. Carmichael. 1996. Double fertilization in Gnetales: implications for understanding reproductive diversification among seed plants. International Journal of Plant Sciences 157 : S77-S94. | pdf

Carmichael, J.S. and W.E. Friedman. 1996. Double fertilization in Gnetum gnemon (Gnetaceae): its bearing on the evolution of sexual reproduction within the Gnetales and the anthophyte clade. American Journal of Botany 83: 767-780. | pdf


Carmichael, J.S. and W.E. Friedman. 1995. Double fertilization in Gnetum gnemon, a nonflowering seed plant: the relationship between the cell cycle and sexual reproduction. Plant Cell 7: 1975-1988. | pdf

Friedman, W.E. 1995. Organismal duplication, inclusive fitness theory and altruism: understanding the evolution of endosperm and the angiosperm reproductive syndrome. Proceedings of the National Academy of Sciences 92: 3913-3917. | pdf


Friedman, W.E. 1994. The evolution of embryogeny in seed plants and the developmental origin and early history of endosperm. American Journal of Botany 81: 1468-1486. | pdf

Liu, L., J.F.D. Dean, W.E. Friedman and K.-E.L. Eriksson. 1994. A laccase like phenoloxidase is correlated with lignin biosynthesis in Zinnia elegans stem tissues. Plant Journal 6: 213-224. | pdf


Friedman, W.E. 1993. The evolutionary history of the seed plant male gametophyte. Trends in Ecology and Evolution 8: 15-21. | pdf


Friedman, W.E. 1992. Double fertilization in nonflowering seed plants. International Review of Cytology 140: 319-355. | pdf

Crook, R.W. and W.E. Friedman. 1992. Effects of pollen number and archegonial number on fertilization in Douglas fir: significance for seed orchard management. Canadian Journal of Forest Research 22: 1483-1488. | pdf

Friedman, W.E. 1992. Evidence of a pre-angiosperm origin of endosperm: implications for the evolution of flowering plants. Science 255: 336 339. | pdf


Friedman, W.E. 1991. Double fertilization in Ephedra trifurca, a non flowering seed plant: the relationship between fertilization events and the cell cycle. Protoplasma 165: 106-120. | pdf

Holaway, B.L., M.C. Trull, W.E. Friedman, and R.L. Malmberg. 1991. A developmentally regulated antigen associated with calcium oxalate and calcium phosphate crystals in tobacco anthers. Planta 186: 13-16. | pdf

Choi, J.S. and W.E. Friedman. 1991. Development of the pollen tube in Zamia furfuracea and its evolutionary implications. American Journal of Botany 78: 544-560. | pdf


Friedman, W.E. 1990. Sexual reproduction in Ephedra nevadensis (Ephedraceae): further evidence of double fertilization in a nonflowering seed plant. American Journal of Botany 77: 1582-1598. | pdf

Friedman, W.E. 1990. Double fertilization in Ephedra nevadensis, a nonflowering seed plant: its bearing on the origin of angiosperms. Science 247: 951-954. | pdf


Friedman, W.E. and E.M. Gifford. 1988. Division of the generative cell and late development of the male gametophyte of Ginkgo biloba. American Journal of Botany 75: 1434-1442. | pdf


Friedman, W.E. 1987. Morphogenesis and experimental aspects of growth and development of the male gametophyte of Ginkgo biloba in vitro. American Journal of Botany 74: 1816-1830. | pdf

Friedman, W.E. 1987. Growth and development of the male gametophyte of Ginkgo biloba within the ovule (in vivo). American Journal of Botany 74: 1797-1815. | pdf


Friedman, W.E. and T.E. Goliber. 1986. Photosynthesis in the female gametophyte of Ginkgo biloba. American Journal of Botany 73: 1261-1266. | pdf


Robichaux, R.H., P.W. Rundel, W.L. Stemmermann, J.E. Canfield. S.R. Morse and W.E. Friedman. 1984. Tissue water deficits and plant growth in wet tropical environments. In: Physiological Ecology of Plants of the Wet Tropics. H.A. Mooney, E. Medina, and C. Vasquez-Yaney (eds.). Junk Publishers, The Hague, pp. 99-112. | pdf


Benzing, D.H., W.E. Friedman, G. Peterson and A. Renfrow. 1983. Shootlessness, velamentous roots, and the pre-eminence of Orchidaceae in the epiphytic biotope. American Journal of Botany 70: 121-133. | pdf


Benzing, D.H., D.W. Ott, and W.E. Friedman. 1982. Roots of Sobralia macrantha (Orchidaceae): structure and function of the velamen-exodermis complex. American Journal of Botany 69: 608-614. | pdf


Benzing, D.H. and W.E. Friedman. 1981. Mycotrophy: its occurrence and possible significance among epiphytic Orchidaceae. Selbyana 5: 243-247. | pdf

Benzing, D.H. and W.E. Friedman. 1981. Patterns of foliar pigmentation in Bromeliaceae and their adaptive significance. Selbyana 5: 224-240. | pdf