Liriodendron tulipifera flower

The University of North Carolina
A Department of the North Carolina Botanical Garden


Collectors of the University of North Carolina Chapel Hill Herbarium

Max Hoyt Hommersand
(b. 10 July 1930)

Information compiled Carol Ann McCormick,
Curator of the University of North Carolina Chapel Hill Herbarium


B. A. University of California,
Berkeley 1954

Ph.D. University of California,
Berkeley 1958


Max Hommersand's area of research is the morphology, systematics and biography of the marine algae, with emphasis on the red algae. He has a world-wide collection of over thirty thousand specimens of marine algae for use in developmental studies. Research facilities include a Zeiss photomicroscope for light microscopy, three large culture rooms for growing algae, and other facilities for investigating the evolutionary biology and phylogeny of the marine algae.

Dr. Hommersand is the Curator of Algae at the University of North Carolina Herbarium. In 2013 the National Science Foundation funded the Macroalgal Digitization Project with a goal of imaging, databasing and georeferencing over 1.1 million algae specimens from 49 herbaria across North America.  NCU is contributing to this effort, and our specimens are available at

Those interested in Dr. Hommersand’s research or specimens should contact him via email at, or via mail at Biology Department, Coker Hall, CB#3280, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280 USA.

Kari Kozak, Willaim R. Burk and Ian Ewing of the John N. Couch Biology Library of the University of North Carolina at Chapel Hill have compiled a bibliography of Hommersand’s publications.

Haru “Fran” Chisaki Hommersand, Max’s wife, and their son, Eric A. Hommersand, frequently collect algae together with Max.  Fran earned a B.A. in Botany from the University of California in Berkeley, and Phycodrys franiae S-M. Lin & W.A. Nelson is named in her honor.


Selected references:

Hommersand, M.H. and S. Fredericq. 1988. An investigation of cystocarp development in Gelidium pteridifolium with revised description of the Gelidiales (Rhodophyta). Phycologia 27: 254-272.

Fredericq, S. and M.H. Hommersand. 1989. Proposal of the Gracilariales ord. mov. (Rhodophyta) based on an analysis of the reproductive development of Gracilaria verrucosa. J. of Phycology 25(2): 213-227.

Fredericq, Suzanne and Max H. Hommersand.  1989.  Comparative morphology and taxonomic status of Gracilariopsis (Gracilariales, Rhodophyta).  J. of Phycology 25(2):  228-241.

Hommersand, Max H.  1990.  The Coralline red algae:  An analysis of the genera and subfamilies of nongeniculate Corallinaceae.  Phycologia 29(1):  126-127. 

Coomans, R.J. and M.H. Hommersand. 1990. Chapter 12: Vegetative growth and organization. In: K. Cole and R. Sheath (eds.), The Biology of the Red Algae. Cambridge University Press, New York.

Hommersand, M.H. and S. Fredericq. 1990. Chapter 13: Sexual reproduction and cystocarp development. In: K. Cole and R. Sheath (eds.), The Biology of the Red Algae. Cambridge University Press, New York.

Hommersand. M.H. 1990. Biogeography of the marine red algae of the north Atlantic Ocean. In: D. Barbary and G. South (eds.), Evolutionary Biography of the Marine Algae of the North Atlantic. NATO ASI Series G: Ecological Sciences Vol. 22. Springer-Verlag, Berlin.

Fredericq, S. and M.H. Hommersand. 1992. Morphology and systematics of Acanthococcus antarcticus (Cystocloniaceae, Rhodophyta). Phycologia 31: 101-118.

Hommersand, M., S. Fredericq, and J. Cabioch. 1992. Developmental morphology of Gigartina pistillata (Gigartinaceae, Rhodophyta). Phycologia 31: 300-325.

Fredericq, S., J. Brodie, and M.H. Hommersand. 1992. Developmental morphology of Chondrus crispus (Gigartinaceae, Rhodophyta). Phycologia 31(6):  542-563.

Hommersand, Max H., Michael D. Guiry, Suzanne Fredericq and Geoffrey L. Leister.  1993.  New perspectives in the taxonomy of Gigartinaceae (Gigartinales, Rhodophyta).  Hydrobiologia 260/261:  105-120.

Freshwater, D. Wilson, Suzanne Fredericq and Max H. Hommersand.  1995.  A molecular phylogeny of the Gelidiales (Rhodophyta) based on analysis of plastid rbcL nucleotide sequences.  J. of Phycology 31(4):  616-632. 

Hommersand, Max H. 1995.  The marine benthic flora of southern Australia.  Rhodophyta Part IIIA Bangiophyceae and Florideophyceae (Acrochaetiales, Nemaliales, Gelidiales, Hildenbradiales and Gigartinales sensu lato.  Phycologia 34(3):  251-252.

Hommersand, Max H. and Suzanne Fredericq.  1997.  Characterization of Schizoseris condensata, Schizoserideae trib. nov. (Delesseriaceae, Rhodophyta)  J. of Phycology 33(3):  475-490.

Hommersand, Max H. and Suzanne Fredericq.  1997.  Characterization of Myriogramme livida, Myriogrammeae trib. nov. (Delesseriaceae, Rhodophyta).  J. of Phycology 33(1):  106-121.  

Hommersand, Max H.  1998.  Taxonomy of economic seaweeds:  with reference to some Pacific species.  Phycologia  37(2):  154-155.

Hommersand, Max H., Sarah M. Wilson and Gerald T. Kraft.  1998.  Mophology and systematics of Rhodocallis elegans, Rhodocallideae, trib. nov. (Ceramiaceae, Rhodophyta), from southeastern Australia.  J. of Phycology 34(5):  865-879.

Hommersand, Max H.  1999.  The marine benthic flora of southern Australia, Rhodophyta, Part IIIC (CeramialesCeramiaceae, Dasyaceae).  Phycologia 38(3):  251-252.

Lin, Showe-Mei, Max H. Hommersand and G. T. Kraft.  2001.  Characterization of Hemineura frondosa and the Hemineuraceae trib. nov. (Delesseriaceae, Rhodophyta) from southern Australia.  Phycologia 40(2):  135-146.

Lin, Showe-Mei, Suzanne Fredericq and Max H. Hommersand.  2001.  Systematics of the Delesseriaceae (Ceramiales, Rhodophyta) based on large subunit rDNA and rbcL sequences, including the Phycodryoideae, subfam. nov.  J. of Phycology 37(5):  881-899.

Hughey, Jeffery R., Paul C. Silva and Max H. Hommersand.  2001.  Solving taxonomic and nomenclatural problems in Pacific Gigartinaceae (Rhodophyta) using DNA from type material.  J. of Phycology 37(6):  1091-1109.

Liao, Lawrence M. and Max H. Hommersand.  2003.  A morphological study and taxonomic reassessment of the generitype speces in the Gracilariaceae.  J. of Phycology 39(6):  1207-1232.

Gurgel, Carlos Frederico D., Lawrence M. Liao, Suzanne Fredericq and Max H. Hommersand.  2003.  Systematics of Gracilariopsis (Gracilariales, Rhodophyta) based on rbcL sequence analyses and morphological evidence.  J. of Phycology 39(1):  154-171.

Lin, Showe-Mei, Max H. Hommersand and Suzanne Fredericq.  2004.  Two new species of Martensia (Delesseriaceae, Rhodophyta) from Kenting National Park, southern Taiwan.  Phycologia 43(1):  13-25.

Lin, Showe-Mei, Suzanne Fredericq and Max H. Hommersand.  2004.  Augophyllum, a new genus of the Delesseriaceae (Rhodophyta) based on rbcL sequence analysis and cystocarp development.  J. of Phycology 40(5):  962-976. 

Saunders, Gary W. and Max H. Hommersand.  2004.  Assessing red algal supraordinal diversity and taxonomy in the context of contemporary systematic data.  Am. J. of Botany 91(10):  1497-1507. 

Hommersand, Max H., D. Wilson Freshwater, Juan M. Lopez-Bautista and Suzanne Fredericq.  2006.  Proposal of the Euptiloteae Hommersand et Fredericq, trib. nov. and transfer of some southern hemisphere Ptiloteae to the Callthamnieae (Ceramiaceae, Rhodophyta).  J. of Phycology 42(1):  203-225. 

Lin, Showe-Mei and Max H. Hommersand.  2007.  Conspecificity of Holmesia neurymenioides with Reinboldiella warburgii (Ceramiales, Rhodophyta) from northeastern Taiwan on the basis of cystocarp development and rbcL sequence analysis.  Phycologia 46(3):  247-256. 

Hughey, Jeffery R. and Max H. Hommersand.  2008.  Morphological and molecular systematic study of Chondracanthus (Gigartinaceae, Rhodophyta) from Pacific North America.  Phycologia 47(2):  124-155.

Cho, Tae Oh, Max H. Hommersand, Boo Yeon Won and Suzanne Fredericq.  2008.  Generic boundaries and phylogeny of Campylaephora (Ceramiaceae, Rhodophyta), including Campylaephora californica (Farlow) comb. nov.  Phycologia 47(3):  321-333.

Cho, Tae Oh, Sung Min Boo, Max H. Hommersand, Christine A. Maggs, Lynne McIvor and Suzanne Fredericq.  2008.  Gayliella gen. nov. in the tribe Ceramieae (Ceramiaceae, Rhodophyta) based on molecular and morphological evidence.  J. of Phycology 44(3):  721-738.  

Rodriguez-Prieto, Conxi and Max H. Hommersand.  2009.  Behaviour of the nuclei in pre- and postfertilization stages in Kallymenia (Kallymeniaceae, Rhodophyta).  Phycologia 48(3):  138-155.

Hommersand, Max H. and D. Wilson Freshwater.  2009.  Gracilaria hummii sp. nov. (Gracilariales, Rhodophyta), a new name for the agarophyteGracilaria confervoides” harvested in North Carolina during World War II.  J. of Phycology 45(2):  503-516.

Lin, Showe-Mei, Max H. Hommersand, Suzanne Fredericq and Olivier DeClerck.  2009.  Characterization of Martensia (Delesseriaceae, Rhodophyta) based on morphological and molecular study of the type species, M. elegans and M. natalensis sp. nov. from South Africa.  J. of Phycology 45(3):  678-691.

Hughey, Jeffery R. and Max H. Hommersand.  2010.  A molecular study of Mazzaella (Gigartinaceae, Rhodophyta) and morphological investigation of the splendens clade from Pacific North America.  Phycologia 49(2):  113-135.

Hommersand, Max H., Geoffrey L. Leister, Maria Eliana Ramirez, Paul W. Gabrielson and Wendy A. Nelson.  2010.  A morphological and phylogenetic study of Glaphyrosiphon gen. nov. (Halymeniaceae, Rhodophyta) based on Grateloupia intestinalis with descriptions of two new species:  Glaphyrosiphon lindaueri from New Zealand and Glaphyrosiphon chilensis from Chile.  Phycologia 49(6):  554-573.

Nelson, Wendy A., Geoffrey L. Leister and Max H. Hommersand.  2011.  Psilophycus alveatus gen. et comb. Nov., a basal taxon in the Gigartinaceae (Rhodophyta) from New Zealand.  Phycologia 50(3):  219-231.

Hommersand, Max H., Richard L. Moe, Charles D. Amsler and Suzanne Fredericq.  2011.  Notes on the systematics and biogeographical relationships of Antarctic and sub-Antarctic Rhodophyta with descriptions of four new genera and five new species.  IN The Biology of Polar Benthic Algae, ed. Christian Wiencke.  Walter de Gruyter GmbH & Co. KG, Berlin/New York.

Thrainsson, Sigurdur A. and Max H. Hommersand.  2012.  New features in the vegetative and reproductive morphology of Cystoclonium purpureum (Cystocloniaceae, Rhodophyta) from the North Atlantic Ocean.  European Journal of Phycology 47(4):  384-392.

Lin, Showe-Mei, Roberta D’Archino and Max Hommersand.  2012.  A new method of cystocarp development in the red algal genus Callophyllis (Kallymeniaceae) from Chile.  J. of Phycology 48(3):  784-792.

Lin, Showe-Mei, Wendy A. Nelson and Max H. Hommersand.  2012.  Hymenenopsis heterophylla gen. et sp. nov. (Delesseriaceae, Rhodophyta) from New Zealand, based on a red alga previously known as Hymenena palmata f. marginata sensu Kylin, with emphasis on its cystocarp development.  Phycologia 51(1):  62-73. 

Hommersand, Max H. and Conxi Rodgriguez-Prieto.  2012.  Developmental morphology and systematics of Trematocarpus dichotomus (Sarcodiaceae, Rhodophyta) from Chile.  Phycologia 51(5):  586-595.

Rodriguez-Prieto, Conxi, D. Wilson Freshwater and Max H. Hommersand.  2013.  Vegetative and reproductive development of Mediterranean Gulsonia nodulosa (Cermiales, Rhodophyta) and its genetic affinities.  Phycologia 52(4):  357-367.

Rodrigues-Prieto, Conxi, Gianfranco Sartoni, Showe-mei Lin and Max H. Hommersand.  2013.  Comparative morphology and systematics of Chondrymenia lobate from the Mediterranean Sea and a phylogeny of the Chondrymeniaceae fam. nov. (Rhodophyta) based on rbcL sequence analysis.  2013.  European Journal of Phycology 48(2):  188-199. 

Rodriguez-Prieto, Conxi and Max H. Hommersand.  2014.  Developmental morphology and systematics of Trematocarpus dichotomus (Sarcodiaceae, Rhodophyta) from Chile.  Phycologia 51(5):  586-595.

Rodriguez-Prieto, Conxi, D. Wilson Freshwater and Max H. Hommersand.  2014.  Morphology and phylogenetic systematics of Ptilocladiopsis horrida and proposal of the Ptilocladiopsidaceae fam. nov. (Gigartinales, Rhodophyta). Phycologia 53(4):  383-395.

Rodriguez-Prieto, Conxi, D. Wilson Freshwater, Max H. Hommersand.  2016.  Gracilaria corallicola and G. multipartita (Gracilariales, Rhodophyta), two related flattened European species.  European Journal of Phycology 51(4):  444-460.

Lin, Show-Mei and Max H. Hommersand.  2016.  Developmental morphology and phylogeny of Paraglossum amsleri sp. nov. (Delesseriaceae, Rhodophyta), a species from Antarctica previously known as Delesseria lancifolia.  Phycologia 55(1):  21-32. 

Hughey, Jeffery R., Max H. Hommersand, Paul W. Gabrielson, Kathy Ann Miller and Timothy Fuller.  2017.  Analysis of the complete plastomes of three species of Membranoptera (Ceramiales, Rhodophyta) from Pacific North America.  J. of Phycology  53(1):  3243.  (DOI:  10.1111/jpy.12472)

Hommersand, Max H. and D. Wilson Freshwater.  Morphology and molecular systematics of the Dasyptileae, a new tribe in the Callithamniaceae (Ceramiales) containing Dasyptilon and Plumariopsis.  Abstract, Phycological Society of America Meeting, June 2018 in Monterey, California, USA. 


Anonymous (2006) Hommersand receives lifetime achievement award. University Gazette 31(1): 8. Chapel Hill, North Carolina, USA.

Max Hommersand, a biology professor who joined the University more than 46 years ago, recently received the 2005 Award of Excellence from the Phycological Society of America (PSA). Hommersand is a professor emeritus in the biology department. Phycology is the study of algae and the society is the largest publisher of papers on algae in the world.

The award was presented at the international meeting in Durban, South Africa, and recognizes phycologists who have demonstrated sustained scholarly contributions in and impact on the field of phycology over their careers. Honorees have also provided service to the PSA and other phycological societies. "A committee from the society looks over the work of different researchers," Hommersand explained. "They are looking back over the impact of your work over a lifetime."

Hommersand's area of research is the morphology, systematics, and biology of the marine algae (seaweeds), with emphasis on the red algae. He has a collection of over 30,000 specimens of marine algae for use in developmental studies.

"It was a surprise," Hommersand said of the honor. "I was very pleased to be recognized and placed in the same group as some of my colleagues who have received the award."

Hommersand came to Carolina in 1959 and stayed here first as an instructor before becoming a professor. He retired in January 1998, but still comes to the office seven days a week, he said. "I have filing cabinets full of unpublished data that keeps me motivated," he said. "There is so much that has been done by me and my students that is just getting dust. I want to get the unpublished information, from my file cabinets and my head, out. I have the opportunity now that I am retired into this effort."

His fascination with algae and his distinguished career began more than 60 years ago. "I started with the Natural History Museum in San Diego," Hommersand said. "This was during World War II, and I took a field trip from the musuem. I was 13 at the time. We arranged to out to the Scripps Institute of Oceanography and we met with researchers. I actually made a collection that I still have. From the time I was 13, I was collecting." He first researched the organisms while an undergraduate student at the University of California at Berkeley in 1948.

Today, he sees the field continuing to evolve. "A lot of people around the world now are using molecular techniques to look at all algae," Hommersand said. "There is already a great expansion in the use of molecular tools to study the systematics of algae. More people are collecting with scuba and submersibles in deeper water around the world. A lot of the picture of the classification and distribution of marine algae are starting to come from the newer collections that are being made this way."

Always a researcher, Hommersand has an idea about where phycology should go in the future. "I think someone should do follow-up research to expeditions from the early 1800's that went to the remote places of the world," he said. "Those expeditions were to collect everything under the sun, by the French, British, and Germans. They hit all these little islands in the Southern Hemisphere. Since then, no one has sent a ship around the world to look at those remote areas. It is conceivable to go back and re-survey the areas that were done in the 19th centiry and look at them from a modern perspective. Much could be learned by doing that."

Anonymous (2005) PSA Awards of Excellence, 2005: Thanarapu Vedanta Desikachary, Max Hoyt Hommersand, and Frank Eric Round. Phycological Newsletter, a publication of the Phycological Society of America 41(2): 2.


Max, as he is known to most of us, has had (and continues to have) a remarkable career of great significance in terms of teaching, scholarship and service to phycology. He received his Bachelor’s degree from the University of California at Berkeley in Botany in 1954. He received his Doctorate in Botany from the University of California at Berkeley under the aegis of Professor George F. Papenfuss where he produced a massive dissertation on the morphology and taxonomy of selected Ceramiaceae and Rhodomelaceae. In the fall of 1957, Max was awarded a two-year NSF [National Science Foundation] Postdoctoral fellowship from Harvard University. Max has been on the faculty of the University of North Carolina at Chapel Hill for over 38 years and has supervised more than 22 doctoral students.

For people who know Max, his being an energetic and active Professor Emeritus is not a great surprise. According to Paul Silva, Max was a precocious high school student the year they met (1946) at the Allan Hancock Foundation. As a young student, Paul encountered Max “reading Fritsch (Structure and Reproduction of the Algae) while eating sandwiches!” Max was fascinated by seaweeds after being introduced to them on nature walks by E. Yale Dawson (following World War II). Actually, Max’s fascination and passion for seaweeds has been his signature trait throughout his life. He has traveled the world collecting material for his phycological studies.

Many contemporaries of Max consider him to be one of the great phycological intellects of the last half century. He and his many collaborators have had unparalleled contributions to the fields of seaweed biogeography and red algal systematics. He has published more than 68 major scientific papers. His evolution from a classical macro-algal taxonomist to one of the worlds’ leaders in using and interpreting molecular data together with more classical observations on algal morphology and reproduction is unique among his generation of phycologists. According to Mike Guiry, “the significance of the development of the female reproductive apparatus before and after fertilization was first recognized by Schmitz in Germany, pursued by Kylin in Sweden, and by Papenfuss in Berkeley, but it was Max and his co-workers who have striven to establish the value of the hypotheses.”

Perhaps the last 15 years have been most significant for Max in terms of his professional accomplishments. Working with a number of colleagues, Max has significantly altered our genetic level understanding of the classical Order Gigantinales. He has revised the taxonomic understanding of key genera in the Ceramiales, Gracilariales and Gelidiales, and improved our understanding of red algal phylogeny and phylogeography. Max has published seminal papers highlighting the information to be gleaned by marrying his extensive knowledge of marine floras and in particular, the red algae, with what we know of plat tectonic movements. He and his co-workers have used the huge potential of DNA sequences in constructing phylogenetic hypotheses. As Steve Murray writes, “today, almost 50 years following the award of his dissertation, Max is at the top of his game and continues to impact phycology.”

Max continues to be a model and an inspiration to a new generation of scientists in phycology from around the world. Max Hoyt Hommersand has demonstrated the very essence of what it means to be nominated and receive the PSA [Phycological Society of America] Award of Excellence.




University of North Carolina Chapel Hill Herbarium (NCU)
CB# 3280, Coker Hall
University of North Carolina at Chapel Hill
Chapel Hill, NC 27599-3280  USA
phone: +1 (919) 962-6931


Last Updated: 23 January 2019