Image of the Library Building

Barbara M. Thiers

Patricia K. Holmgren Director, William and Lynda Steere Herbarium, Vice President, and Curator of Bryophytes

Ph.D., University of Massachusetts
Amherst, MA, 1982


Hepaticae (Liverworts)


Tropical Hepaticae, Herbarium Management, Biodiversity Information Management

Research locations

neotropics, worldwide


As Patricia K. Holmgren Director of the William and Lynda Steere Herbarium, I am responsible for overseeing the Garden’s 7.8 million collections of algae, bryophytes, fungi and vascular plants and the approximately 30 staff members who manage these collections. The Steere Herbarium is the largest in the Western Hemisphere, and second largest in the world. It is the world’s most heavily used herbaria in terms of the number of specimens loaned or imaged on demand, and the number of visitors to the Herbarium. I have been particularly interested in the application of information technology to herbarium management, and to increasing access to specimen-based data for the scientific community. These interests have led to the development of The C. V. Steere Virtual Herbarium, which contains a searchable database of digitized herbarium specimens (3.25 million so far, with 400,000 added each year). The Virtual Herbarium also includes Index Herbariorum, of which I am the Editor, the Index to American Botanical Literature, and World Floras and Monographs, an electronic publication series. I have been involved in the development of the Network Integrated Biocollections Alliance, a nationwide initiative to digitize all biodiversity collections housed in U.S. institutions I am President-Elect of the Society for the Preservation of Natural History Collections (2018-2020), Vice President of the Natural Science Collections Alliance, Chair of the Systematics Collections Committee of the American Society of Plant Taxonomists and member of the External Advisory Board of iDigBio, the national collections digitization hub. The subject of my research is the Hepaticae. In particular, I am interested in the systematics and morphology of the largest family of Hepaticae, the Lejeuneaceae. This family is primarily tropical in distribution, and its members can be found growing, often profusely, on the bark and sometimes on living leaves of trees in tropical rainforests. My studies of these small but beautiful plants have taken me to Australia, Colombia, Dominican Republic, Ecuador, French Guiana, Papua New Guinea, Puerto Rico and Venezuela.

Selected Publications

1982. Branching in the Lejeuneaceae I: A comparison of branch development in Aphanolejeunea and Cololejeunea. Bryologist 85: 104-109.

1982. Type studies in the Lejeuneaceae. I. Archilejeunea pabstii, Hygrolejeunea pacifica, and Hygrolejeunea spongia. Brittonia 34: 294-298.

1983. Type studies in the Lejeuneaceae. II. Pteryganthus, a new subgenus of Lopholejeunea. Brittonia 35: 81-86.

1983. Index to the genera and species of Hepaticae described by William Mitten. Brittonia 35: 271-300.

1983. The fungus herbarium of the Carnegie Museum of Natural History (CM), Pittsburgh, Pennsylvania. Brittonia 35: 367-373. (with Dennis Desjardin and Andrew S. Methven).

1984. Branch characters significant to subfamilial classification of Lejeuneaceae (Hepaticae). Syst. Bot. 9: 33-41.

1984. Branching in the Lejeuneaceae II. Nipponolejeuneoideae, Tuyamaelloideae, and Myriocoleoideae. Lindbergia 10: 4-18.

1984. Type studies in Lejeuneaceae III. Lopholejeunea erugata, a new name for Ptychocoleus inermis. Brittonia 36: 174-177.

1984. Introduction to a reprinted edition of Richard Spruce’s Hepaticae Amazonicae et Andinae. Contr. New York Bot. Gard. 15: IX-XII.

1984. Index to species described in Hepaticae Amazonicae et Andinae by Richard Spruce, with nomenclatural updating. Contr. New York Bot. Gard. 15: (1)-(14).

1985. Branching in the Lejeuneaceae III. Ptychanthoideae. In: Gradstein, S. R., (ed.) Studies in the Lejeuneaceae subfamily Ptychanthoideae. Beih. Nova Hedwigia 80: 31-61.

1985. Austrolejeunea bidentata, a new species of Lejeuneaceae subfamily Tuyamaelloideae from Australia. Bryologist 88: 350-352.

1986. Branching in the Lejeuneaceae. IV. Lejeuneoideae. Nova Hedwigia 42: 237-275.

1987. A preliminary account of Colura (Hepaticae, Lejeuneaceae) in Australia. Brittonia 39: 175-179.

1987. Lepidolejeunea queenslandica, a new species of Lejeuneaceae subfamily Lejeuneoideae from Australia. In: Buck, W. R. (ed.) Mem. New York Bot. Gard. 45: 556-560.

1988. Morphological adaptations of the Jungermanniales (Hepaticae) to the tropical rainforest habitat. J. Hattori Bot. Lab. 64: 5-14.

1988. The Australian species of Cololejeunea. in Engel, J. (ed.) Beih. Nova Hedwigia 90: 113-146.

1989. (with Roy E. Halling). Type specimens of agarics, boletes and gasteromycetes in the San Francisco State University herbarium (SFSU). Mycotaxon 34:267-268.

1989. (with S. R. Gradstein). Lejeuneaceae (Hepaticae) of Australia. I. Subfamily Ptychanthoideae of Australia. Mem. New York Bot. Gard. 52: 1-79.

1989. (with W. R. Buck) Bryological studies in the tropics. Pp. 484-493. In Campbell, D. & D. Hammond, (eds.), World Strategy for the Floristic Inventory of Tropical Forests, New York Botanical Garden, Bronx.

1990. An overview of the Lejeuneaceae in Australia. Tropical Bryology 2: 273-283. 1990.

1992. (with S. Emory). The history of bryology in California. Bryologist 95: 68-78.

1993. New Species of Cheilolejeunea and Otolejeunea (Hepaticae; Lejeuneaceae) from Australia. Brittonia 44: 160-165.

1993. A Re-evaluation of Cheilolejeunea subgenus Cheilolejeunea and Xenolejeunea. Tropical Bryology 5: 11-21.

1993. An index to the species of mosses and lichens described by William Mitten. Memoirs of the New York Botanical Garden 67:1-113. (project coordinator).

1993. A monograph of Pleurozia (Hepaticae, Pleuroziaceae). The Bryologist 96: 517-554.

1993. (with P. K. Holmgren & J. A. Kallunki). A short description of the collections of the New York Botanical Garden Herbarium (NY). Brittonia 48: 285-296.

1997. Cheilolejeunea in Australia: Description of new taxa and key. J. Hattori Bot. Lab. 82: 321-328.

1997. Lejeunea bischlerae, a new species of Lejeunea subgenus Microlejeunea from Australia. Cryptogamie. Bryologie et LichÈnologie. Cryptogamie, Bryol. LichÈnol. 18: 223-226.

  1. (with Roy E. Halling). Memorial: Harry D. Thiers 1919-2000. Mycologia 5: 1271-1275.


  1. (With Q. Wu & D. Pfister). Preservation and use of fungal herbarium specimens.  In: Measuring and Monitoring Biological Diversity: Standard Methods for Fungi.    Mueller, G. M., G. F. Bills, A. Y. Rossman, and M. S. Foster (eds.).
  2. (with G. A. Long, G., K. Tripp, T. Forrest, & S. Fraser).  The New York Botanical Garden.  Harry N. Abrams, Inc.  247 p.
  3. (with W. Wayt. Thomas). O Jardim Botânico de Nova York e seu herbário virtual.  Ciencia & Cultura (magazine of the Botanical Garden of Rio de Janeiro).  Pp, 35—38.  Jan—Mar 2010.
  • (with J. Beach, L. Ford, R. Guralnick, M. Mares, M. Westneat and B. Wiegmann). Establishing a National Digital Biological Collections Resource —
  • A strategic plan for establishing a network integrated biocollections alliance.
  1. with W. Wayt. Thomas. O Jardim Botânico de Nova York e seu herbário virtual.

Ciencia & Cultura (magazine of the Botanical Garden of Rio de Janeiro).  Pp, 35—38.  Jan—Mar 2010.

  • with W. W. Thomas. From manuscript to the public: modes of monographic

publication in Stuessy & Lack, Monographic Plant Systematics: Fundamental Assessment of Plant Biodiversity.  Regnum. Vegetabile 153.  Gantner, Königstein.

Herbaria.  In: Public Garden Management by Donald A. Rakow , A.  J. Wiley & Sons.

  1. With Tulig, M., N. Tarnowsky, M. Bevans, & A. Kirchgessner. 2012. Increasing the efficiency of digitization workflows for herbarium specimens.  Zookeys. 209: 103-113.


Notes on Early Land Plants Today. 11.  Microlejeunea bischlerae (B. M. Thiers) comb. Nov.  Phytotaxa 65: 59.   DOI10.11646/phytotaxa.65.1.16


  1. With J. Hanken, L. McDade, J. Beach, J. Cook and L. Ford. An Implementation Plan for the Network Integrated Biocollections Alliance American Institute of Biological Sciences. Reston, VA.


  1. Thiers B.M., N. Wilson, R.E. Halling 2013. Making Scientific Vouchers of North American Macrofungi: How Documenting the Fungi You Encounter Contributes to the Mycoflora of North America. McIlvainea 22: 19-24.


  • with Tulig, M. Tarnowsky, N., Bevans, M., and Kirchgessner, T.  Digitizing the New York Botanical Garden Herbarium: The Holmgren Influence on the Past, Present, and Future.  Memoirs of the New York Botanical Garden. 108:45-58. press.


  1. with 22 coauthors; C. Lamana, Lead Author. Functional Trait space and the latitudinal diversity gradient.  Proceedings of the National Academy of Sciences 111: 1375-13750. DOI10.1073/pnas.1317722111


  1. with Matthew Pace Nicole Tarnowsky, et al. An updated description of the collections and history of The New York Botanical Garden Herbarium (NY-1995-2015).  Brittonia 68: 317-323. DOI10.1007/s12228-016-9422-8


  • with M. Tulig and K. Watson. Digitization of The New York Botanical Garden Herbarium. Brittonia 68.  1007/s12228-016-9423-7


  • with 4 other authors, G. Goldsmith, lead author. Cyberinfrastructure for an integrated biotaical information network to investigate the ecological impacts of global climate change on plant biodiversity.  DOI 10.7287/PEERJ.PREPRINTS.2615V1


  1. with 18 other authors, B. Enquist, lead author). Plant-O-Matic: a dynamic and mobile guide to all plants of the Americas.  Methods in Ecology and Evolution.  DOI


  1. with 9 other authors, L. Krishtalka, lead author. Accelerating the discover of biocollections data.  Technical Report.  Global Biodiversity Information Facility


  1. with 21 other authors, B. S. Maitner, lead author. The bien r package: A tool to access the Botanical Information and Ecology Network (BIEN) database.  Methods in Ecology and Evolution 9:   DOI10.1111/2041-210x.12861


  1. with R. Halling. The Macrofungi Collection Consortium.  Applications in Plant Science

7 p.  Doi:10.1002/aps3.1021.


In Press:


Lejeuneaceae.  Flora of North America. Vol. 22 Bryophytes part 2.  100 ms pages.  Submitted 2010, revised 2013.


Pleuroziaceae.  Flora of North America. Vol. 22 Bryophytes part 2.  6 ms pages September 2010, revised 2014.