2023
Moroni, P. and M. G. Simpson. 2023a. Flora Argentina: Cryptantha (Boraginaceae). Darwiniana 19:17–24.
Moroni, P. and M. G. Simpson. 2023b. Flora Argentina: Greeneocharis (Boraginaceae). Darwiniana 19:36–37.
Moroni, P. and M. G. Simpson. 2023c. Flora Argentina: Johnstonella (Boraginaceae). Darwiniana 19:56–58.
Simpson, M. G. and L. Gross. 2023. Noteworthy Collection: Cryptantha crassisepala (Torrey & A.Gray) Greene var. elachantha I.M.Johnston. Madroño 70:4–8. https://doi.org/10.3120/0024-9637-70.1.4
2022
Simpson, M. G., R. Vanderhoff, J. Bailey, F. Roberts, M. Mulligan, J. P. Rebman, N. Walsh, and M. Koekemoer. 2023. Taxonomic identity of a recently naturalized Senecio species in California. Madroño 69:286–298. https://doi.org/10.3120/0024-9637-69.3.286
Moroni, P. and M. G. Simpson. 2022. Revisión taxonómica del genero Johnstonella (Boraginaceae s. str.) en la Argentina. Darwiniana Nueva Serie 10:260–270. http://www.ojs.darwin.edu.ar/index.php/darwiniana/article/view/1046
Rebman, J. P. and M. G. Simpson. 2022. Three new species of Cryptantha (Boraginaceae) from the Southern Channel Islands of California. Madroño 69: 111-134. https://doi.org/10.3120/0024-9637-69.1.111
Simpson, M. G., K. Hasenstab-Lehman, M. Mabry, and M. Muñoz. 2022. Johnstonella punensis (Boraginaceae), a new species endemic to the dry Puna of Chile. PhytoKeys 197:149–164. https://doi.org/10.3897/phytokeys.197.84833
2021
Moroni, P., A. Martínez, and M. G. Simpson. 2021. Nomenclatural revision of Cryptantha (Boraginaceae s. str.) names linked to South American taxa. PhytoKeys 181: 29-47. https://doi.org/10.3897/phytokeys.181.69740
Simpson, M. G. and J. P. Rebman. 2021. Research in Boraginaceae: A new variety of Cryptantha maritima, Cryptantha pondii resurrected, and Johnstonella echinosepala transferred back to Cryptantha. Phytotaxa 509:185–210. https://doi.org/10.11646/phytotaxa.509.2.3
Simpson, M. G. and J. P. Rebman. 2021. A new species of Cryptantha restricted to dunes in northwestern Baja California, Mexico. Madroño 68:127-137. https://doi.org/10.3120/0024-9637-68.2.127
2020
Simpson, M. G. and R. B. Kelley. 2020. Cryptantha. Pp. 394-403 in T. J. Stephen C. Meyers, Katie E. Mitchell, Tanya Harvey & Linda K. Hardison (ed.), Flora of Oregon. Volume 2: Dicots A-F. Brit Press, Botanical Research Institute of Texas, Fort Worth, Texas.
Simpson, M. G. and R. B. Kelley. 2020. Eremocarya. P. 404 in T. J. Stephen C. Meyers, Katie E. Mitchell, Tanya Harvey & Linda K. Hardison (ed.), Flora of Oregon. Volume 2: Dicots A-F. Brit Press, Botanical Research Institute of Texas, Fort Worth, Texas.
Simpson, M. G. and R. B. Kelley. 2020. Greeneocharis. Pp. 405–406 in T. J. Stephen C. Meyers, Katie E. Mitchell, Tanya Harvey & Linda K. Hardison (ed.), Flora of Oregon. Volume 2: Dicots A-F. Brit Press, Botanical Research Institute of Texas, Fort Worth, Texas.
Simpson, M. G., J. Stephens, and S. Yang. 2020. Noteworthy Collections: Johnstonella angelica (I.M.Johnston) Hasenstab & M.G.Simpson. Madroño 67:5-8. https://doi.org/10.3120/0024-9637-67.1.5
Yost, J. M., K. D. Pearson, J. Alexander, E. Gilbert, L. A. Hains, T. Barry, R. Bencie, P. Bowler, B. Carter, R. E. Crowe, E. Dean, J. Der, A. Fisher, K. Fisher, L. Flores-Renteria, C. M. Guilliams, C. Hatfield, L. Hendrickson, T. Huggins, L. Janeway, C. Lay, A. Litt, S. Markos, S. J. Mazer, D. Mccamish, L. Mcdade, M. Mesler, B. Mishler, M. Nazaire, J. Rebman, L. Rosengreen, P. W. Rundel, D. Potter, A. Sanders, K. C. Seltmann, M. G. Simpson, G. A. Wahlert, K. Waselkov, K. Williams, and P. S. Wilson. 2020. The California Phenology Collections Network: Using digital images to investigate phenological change in a biodiversity hotspot. Madroño 66:130-141. https://doi.org/10.3120/0024-9637-66.4.130
2019
Benet-Pierce, N. and M. G. Simpson. 2019. The taxonomy of Chenopodium hians, C. incognitum, and ten new taxa within the narrow-leaved Chenopodium group in western North America, with special attention to California. Madroño 66:56–75.
Simpson, Michael G. 2019. Plant Systematics, 3rd edition. Elsevier-Academic Press (website).
Simpson, M. G., M. E. Mabry, and K. Hasenstab-Lehman. 2019. Transfer of four species of Cryptantha to the genus Johnstonella (Boraginaceae). Phytotaxa 425:279–289. https://doi.org/10.11646/phytotaxa.425.5.3
2018
Mabry, M. E.* and M. G. Simpson. 2018. Evaluating the monophyly and biogeography of Cryptantha (Boraginaceae). Systematic Botany 43: 53-76. http://dx.doi.org/10.1600/036364418X696978
Mendoza-Díaz, N., H. Flores-Olvera, M. G. Simpson, and M. J. Moore. 2018. A new and unusual endemic species from the Chihuahuan Desert, Mexico: Antiphytum geoffreyi (Boraginaceae, Echiochiloideae). Phytotaxa 367: 275-283. https://doi.org/10.11646/phytotaxa.367.3.7
2017
Aerne-Hains, L.* and M. G. Simpson. 2017. Vegetative anatomy of the Haemodoraceae and its phylogenetic significance. International Journal of Plant Sciences 178: 117-156. https://doi.org/10.1086/689199
Benet-Pierce, N. and M. G. Simpson. 2017. Taxonomic recovery of the species in the Chenopodium neomexicanum complex and description of Chenopodium sonorense sp. nov. Journal of the Torrey Botanical Society 144: 339-356.
http://www.bioone.org/doi/10.3159/TORREY-D-16-00013.1
Guilliams, M. C.*, K. Hasenstab-Lehman*, M. Mabry* and M. G. Simpson. 2017. Memoirs of a frequent flier: Phylogenomics reveals 18 long-distance dispersals between North America and South America in the popcorn flowers (Amsinckiinae, Boraginaceae). American Journal of Botany 104: 1717-1728. https://doi.org/10.3732/ajb.1700369
Simpson, M. G., C. M. Guilliams*, K. E. Hasenstab-Lehman*, M. E. Mabry*, and L. Ripma*. 2017. Phylogeny of the popcorn flowers: Use of genome skimming to evaluate monophyly and interrelationships in subtribe Amsinckiinae (Boraginaceae). Taxon 66: 1406–1420.
https://doi.org/10.12705/666.8
Simpson, M. G., L. A. Johnson and C. M. Guilliams*. 2017. Patterns and processes of American amphitropical disjunctions: New insights. American Journal of Botany 104: 1597-1599. https://doi.org/10.3732/ajb.1700433
Simpson, M. G., L. A. Johnson, T. Villaverde and C. M. Guilliams*. 2017. American Amphitropical Disjuncts: Perspectives from vascular plant analyses and prospects for future research. American Journal of Botany 104: 1600-1650. https://doi.org/10.3732/ajb.1700308 (pdf)
Simpson, M. G. and R. B. Kelley. 2017. Cryptantha nevadensis var. rigida elevated to species with a new name, C. juniperensis. Phytotaxa 295: 227-236. https://doi.org/10.11646/phytotaxa.295.3.3
2016
Chacón, J., F. Luebert, H. H. Hilger, S. Ovcinnikova, F. Selvi, L. Cecchi, C. M. Guilliams*, K. Hasenstab-Lehman*, K. Sutorý,
M. G. Simpson, and M. Weigend. 2016. The borage family (Boraginaceae s.str.): A revised infrafamilial classification based on new phylogenetic evidence, with emphasis on the placement of some enigmatic genera. Taxon 65: 523–546.
http://dx.doi.org/10.12705/653.6
Luebert, F., L. Cecchi, M. W. Frohlich, M. Gottschling, C. M. Guilliams*, H. H. Hilger, K. E. Hasenstab-Lehman*, J. S. Miller, M. Mittelbach, M. Nazaire, M. Nepi, D. Nocentini, D. Ober, R. G. Olmstead, F. Selvi, M. G. Simpson, K. Sutorý, B. Valdés, G. K. Walden, and M. Weigend (Boraginales Working Group). 2016. Familial classification of the Boraginales. Taxon 65: 502-522. http://dx.doi.org/10.12705/653.5
Mabry, M. E.*, R. A. Dowdy*, L. M. Simpson, J. P. Rebman, and M. G. Simpson. 2016. Taxonomy of the winged popcorn flower: Cryptantha pterocarya (Boraginaceae). Phytotaxa 253: 97-130. http://dx.doi.org/10.11646/phytotaxa.253.2.1
McCabe, S. W., M. W. Dodero, and M. G. Simpson. 2016. Dudleya hendrixii: A new, rare species from Colonet Mesa, Baja California. Madroño 63: 359-365. https://doi.org/10.3120/0024-9637-63.4.359
Simpson, M. G., L. M. Simpson, and J. P. Rebman. 2016. A new, large-flowered variety of Eremocarya micrantha (Boraginaceae). Madroño 63: 39-54. https://doi.org/10.3120/0024-9637-63.1.39
2014
Benet-Pierce, N. and M. G. Simpson. 2014. The taxonomy of Chenopodium desiccatum and C. nitens, sp. nov. Journal of the Torrey Botanical Society 141: 161-172. https://doi.org/10.3159/TORREY-D-13-00046.1
Rebman, J. P. and M. G. Simpson. 2014. Checklist of the Vascular Plants of San Diego County, 5th edition. San Diego Natural History Museum Publications.
Ripma, L.*, M. G. Simpson, and K. Hasenstab-Lehman*. 2014. Geneious! Simplified genome skimming methods for phylogenetic systematic studies: A case study in Oreocarya (Boraginaceae). Applications in Plant Sciences 2: 1400062.
http://dx.doi.org/10.3732/apps.1400062
Simpson, Michael G. 2014. Review of Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Subclass Magnoliidae– Caryophyllidae, Vol. 2A. By N. H. Holmgren, P. K. Holmgren, J. L. Reveal, and collaborators. 2012. The New York Botanical Garden Press, Bronx, New York. 742 pp. ISBN 978-0-89327- 520-4, Price $150.00, hardcover. Madroño 61: 146-147.
http://dx.doi.org/10.3120/0024-9637-61.1.146
Simpson, M. G., K. Hasenstab-Lehman*, and R. B. Kelley. 2014. Typification of the name Johnstonella (Boraginaceae). Taxon 63: 930-931.
http://dx.doi.org/10.12705/634.8
Simpson, M. G., R. Dowdy*, J. P. Rebman, R. B. Kelley, and L. M. Simpson. 2014. The recognition of two species in Eremocarya (Boraginaceae): Evidence from fornix bodies, nutlets, corolla size, and biogeography. Madroño 61: 259–275.
https://doi.org/10.3120/0024-9637-61.3.259
2013
Guilliams, C. M.*, B. A. Veno, M. G. Simpson, and R. B. Kelley. 2013. Pectocarya anisocarpa, a new species of Boraginaceae, and a revised key for the genus in western North America. Aliso 31: 1-13. http://dx.doi.org/10.5642/aliso.20133101.02
Silveira, M.* and Simpson, M. G. 2013. Phylogenetic systematics of the mesa mints: Pogogyne (Lamiaceae). Systematic Botany 38: 782-794.
https://doi.org/10.1600/036364413X670313
Simpson, M. G., J. P. Rebman, K. E. Hasenstab-Lehman*, C. M. Guilliams*, and P. McConnell. 2013. Cryptantha wigginsii (Boraginaceae): A presumed extinct species rediscovered. Madroño 60(1): 24-34. https://doi.org/10.3120/0024-9637-60.1.24
Simpson, M. G. and J. P. Rebman. 2013. A new species of Cryptantha (Boraginaceae) from the Sierra de San Pedro Mártir, Baja California, Mexico. Madroño 60(1): 35-45. (pdf) Yost, J. M., M. Bontrager, S. McCabe, D. Burton*, M. G. Simpson, K. M. Kay, and M. Ritter. 2013. Phylogenetic relationships and evolution in Dudleya (Crassulaceae). Systematic Botany 38: 1096-1104. https://doi.org/10.3120/0024-9637-60.1.35
Yost, J. M., M. Bontrager, S. W. McCabe, D. Burton*, M. G. Simpson, K. M. Kay and M. Ritter. 2013. Phylogenetic relationships and evolution in Dudleya (Crassulaceae). Systematic Botany 38: 1096-1104. https://doi.org/10.1600/036364413X674760
2012
Dodero, M. W.* and M. G. Simpson. 2012. Dudleya crassifolia (Crassulaceae), a new species from northern Baja California, Mexico. Madroño 59: 223-229.
Hasenstab-Lehman, Kristen E.* and M. G. Simpson. 2012. Cat’s Eyes and Popcorn Flowers: Phylogenetic Systematics of the Genus Cryptantha s.l. (Boraginaceae). Systematic Botany 37: 738–757. NOTE: Winner of the 2014 Grady Webster Award, given by the American Society of Plant Taxonomists, for best publication during the two year period 2012-2013!
Kelley, R. B., M. G. Simpson, and K. E. Hasenstab. 2012. Cryptantha. Pp. 455-468 in B. G. Baldwin, D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken (eds.), The Jepson Manual: Vascular Plants of California. Second Edition. University of California Press, Berkeley, Los Angeles, London.
Silveira, M., M. G. Simpson, and J. D. Jokerst. 2012. Pogogyne. Pp. 850-851 in B. G. Baldwin, D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken (eds.), The Jepson Manual: Vascular Plants of California. Second Edition. University of California Press, Berkeley, Los Angeles, London.
2010
Benet-Pierce, N. and M. G. Simpson. 2010. Chenopodium littoreum (Chenopodiaceae), a new goosefoot from dunes of south-central coastal California. Madroño 57: 64-72.
Guilliams, C. M.*, Simpson, M. G., and J. P. Rebman. 2011. Calyptridium parryi var. martirense (Montiaceae), a new taxon endemic to the Sierra San Pedro Mártir, Baja California, Mexico. Madroño 58(4): 258-266.
Simpson, M. G., C. M. Guilliams*, and M. Silveira*. 2010. Taxonomy of Calyptridium parryi (Montiaceae). Madroño 57: 145-160.
Simpson, Michael G. 2010. Plant Systematics, 2nd edition. Elsevier-Academic Press. (web site)
2009
Pierce, Nuri and Michael G. Simpson. 2009. Polyaperturate pollen types and ratios of heteromorphism in the monocot genus Conostylis R. Br. (Haemodoraceae). Australian Systematic Botany 22: 16-30.
Simpson, Michael G. and Kristen E. Hasenstab*. 2009. Cryptantha of Southern California. Crossosoma 35: 1-59.
2007
Winner, Annette and Michael G. Simpson. 2007. A new subspecies of Pentagramma triangularis (Pteridaceae). Madroño 54(4): 345-353.
2006
Rebman, Jon P. and Michael G. Simpson. 2006. Checklist of the Vascular Plants of San Diego County. 4th edition. San Diego Natural History Museum, San Diego, California.
Simpson, Michael G. 2006. Plant Systematics. Elsevier-Academic Press. (web site) NOTE: Winner of the Gleason Award, New York Botanical Garden, 2006
Simpson, Michael G. and Darren H. Burton*. 2006. Floral anatomy of the Pontederiaceae and its systematic significance. Aliso 22: 499-519. In: Columbus, J. T., E. A. Friar, J. M. Porter, L. M. Prince, and M. G. Simpson [eds.]. Monocots: Comparative biology and evolution. 2 vols. Rancho Santa Ana Botanic Garden, Claremont, California, U. S. A.
2003
Hargrove, Lori and Michael G. Simpson. 2003. Ultrastructure of heterocolpate pollen in Cryptantha (Boraginaceae). International Journal of Plant Sciences 164(1): 137-151.
2000
Evans, Timothy M., Robert B. Faden, Michael G. Simpson, and Kenneth J. Sytsma. 2000. Phylogenetic relationships in the Commelinaceae: I. A cladistic analysis of morphological data. Systematic Botany 25: 668-691.
1999
Marsden, Kim L.* and Michael G. Simpson. 1999. Eryngium pendletonensis (Apiaceae), a new species from southern california. Madroño 46(1): 55-58.
1998
Simpson, Michael G. 1998. Reversal in ovary position from inferior to superior in the Haemodoraceae: evidence from floral ontogeny. International Journal of Plant Sciences 159(3): 466-479.
Simpson, Michael G. 1998. Haemodoraceae. In: Kubitski, ed. Families and Genera of Flowering Plants. Volume IV. Flowering Plants Monocotyledons. Alismatanae and Commelinanae (except Gramineae). Pp. 212-222. Springer, Berlin.
Simpson, Michael G. and Rudall, P. 1998. Tecophilaeaceae. In: Kubitski, ed. Families and Genera of Flowering Plants. Volume III. Flowering Plants Monocotyledons. Lilianae (except Orchidaceae). Pp. 429-436. Springer, Berlin.
1994
Simpson, Michael G. and Levin, G. A. 1994. Pollen ultrastructure of the biovulate Euphorbiaceae. International Journal of Plant Sciences 155: 313-341.
Levin, Geoffrey A., and Michael G. Simpson. 1994. Phylogenetic implications of pollen ultrastructure in the Oldfieldioideae (Euphorbiaceae). Annals of the Missouri Botanical Garden 81: 203-238.
Levin, Geoffrey A., and Michael G. Simpson. 1994. Phylogenetic relationships of Hymenocardia and Didymocistus (Euphorbiaceae). Annals of the Missouri Botanical Garden 81: 239-244.
1993
Simpson, Michael G. 1993. Septal nectary anatomy and phylogeny in the Haemodoraceae. Systematic Botany 18: 593-613.
1990
Simpson, Michael G. 1990. Phylogeny and classification of the Haemodoraceae. Annals of the Missouri Botanical Garden 77: 722-784.
1989
Simpson, Michael G. 1989. Pollen wall development of Xiphidium coeruleum (Haemodoraceae) and its systematic implications. Annals of Botany 64: 257-269. (pdf)
1988
Simpson, Michael G. 1988. A critique of "Bromeliales, related monocots, and resolution of relationships among Bromeliaceae subfamilies." Systematic Botany 13: 610-614.
Simpson, Michael G. 1988. Embryological development of Lachnanthes caroliniana (Haemodoraceae). American journal of Botany 75: 1394-1408.
1987
Simpson, Michael G. 1987. Pollen ultrastructure of the Pontederiaceae: evidence for exine homology with the Haemodoraceae. Grana 26: 113-126.
1985
Simpson, Michael G. 1985. Pollen ultrastructure of the Tecophilaeaceae. Grana 24: 77-92.
Simpson, Michael G. 1985. Pollen ultrastructure of the Philydraceae. Grana 24: 23-31.
1983
Simpson, Michael G. 1983. Pollen ultrastructure of the Haemodoraceae and its taxonomic significance. Grana 22: 79-103.
1981
Simpson, Michael G. and W. C. Dickison. 1981. Comparative anatomy of Lachnanthes and Lophiola (Haemodoraceae). Flora 171: 95-113.
Non-referred publications
Simpson, Michael G., E. Gergus, and S. C. McMillan. 2014. Laboratory Manual for Organismal Biology: an Evolutionary Approach. 10th edition. Rhynchops Press, California.
Simpson, Michael G. 2013. Plant Collecting and Documentation Field Notebook. 4th edition. Rhynchops Press, California.