Trees and Shrubs Online logo

References

References

References

Focus Arboreta

Collectors' References

Glossary

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
_
_
_
_
_
_

  • U

  • Uchytil, R.J. (1989). Alnus rubra U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer)., Fire Effects Information System (online) (accessed 2021-01-15)
  • Udenhout Trees (2022). Ostrya carpinifolia 'F. C. Moree' [link] (accessed 2022-04-08)
  • Ueda, K. (1980). Taxonomic study of Magnolia sieboldii C. Koch in Acta Phytotaxonomica et Geobotanica 31 117-125 [link] (accessed 2021-06-29)
  • Ueda, K., Yamashita, J. & Tamura, M.N. (2000). Molecular phylogeny of the Magnoliaceae in Proceedings of the International Symposium on the family Magnoliaceae, Guangzhou, China 205–209 Science Press, Beijing
  • Uehara, K. (1965). Illustrated series of trees, Ginkgoaceae 2 in Jumoku Zusetsu
  • Uemura, K. (1997). Cenozoic history of Ginkgo in East Asia 207-221 in Ginkgo biloba—A Global Treasure from Biology to Medicine Springer Verlag, Tokyo
  • Ueno, J. (1950). On Enkianthus. A classification of the genus Enkianthus based upon the characters of pollen grains and of crystals inthe leaf in Journal of the Institute of Polytechnics, Osaka City University 1 55-62
  • Ufimov, R. et al. (2021). Relative performance of customized anduniversal probe sets in target enrichment: A case study in subtribe Malinae. in Appl. Plant Sci 9:e11442
  • Ufimov, R.A. & Dickinson, T.A. (2020). Infrageneric nomenclature adjustments in Crataegus L. (Maleae, Rosaceae) in Phytologia 102:3 177-199 [link] (accessed 2023-07-10)
  • UF|IFAS (2024). The golden rain tree (Koelreuteria elegans ssp. formosana): more foe than friend. University of Florida. Institute Of Food And Agricultural Sciences
  • Uhl, N. W & Dransfield, J (1987). Genera Palmarum. A classification of palms based on the work of Harold E. Moore, Jr. Allen Press, Lawrence, Kansas, USA
  • Uhlig, K. (2017). UWSP says goodbye to champion oak USA Today Network, Stevens Point Journal (accessed 2024-07-10)
  • Uings, J., Moth, B. & Stevenson, M. (2016). Caldwells Nurserymen of Knutsford for two centuries. Cheshire Gardens Trust
  • Ujihara, M., Shinozaki, M. & Kato, M. (1995). Accumulation of phyllodulcin in sweet‐leaf plants of Hydrangea serrata and its neutrality in the defence against a specialist leafmining herbivore. in Population Ecology 37:2 249-257 [link] (accessed 2024-11-21)
  • Umeå University (2008). World’s oldest living tree discovered in Sweden Press release, 16 April 2008
  • Understorey Network (2000 onwards). [nursery website] [link] (accessed 2022-12-23)
  • United States Department of Agriculture (1916). Inventory of Seeds and Plants Imported by the Office of Foreign Seed and Plant Introduction During the Period from October 1 to December 31, 1913 37 Nos. 36259-36936 Government Printing Office, Washington, D.C.
  • United States Department of Agriculture (1922). Inventory of seeds and plants imported by the Office of Foreign Seed and Plant Introduction during the Period from November 1 to December 31, 1919 Government Printing Office, Washington, D.C.
  • United States Department of Agriculture (1923). Inventory of Seeds and Plants Imported by the Office of Foreign Seed and Plant Introduction During the Period from January 1 to March 31, 1921 66 Nos. 52306-52854 Government Printing Office, Washington, D.C.
  • United States Department of Agriculture (1928). Plant Material Introduced by the Office of Foreign Plant Introduction, Bureau of Plant Industry, January 1 to March 31 1926 (F.P.I Nos. 65708–66698) Inventory No. 86 U.S. Government Printing Office, Washington, D.C.
  • United States Department of Agriculture (1929). Plant Inventory No. 91: Plant Material Introduced by the Office of Foreign Plant Introduction, Bureau of Plant Industry, April 1 to June 30, 1927 (Nos. 73050 to 74212) Office of Foreign Plant Introduction, Washington, D.C.
  • United States Department of Agriculture (1995). Commercial suppliers of tree and shrub seed in the United States Miscellaneous Report R8-MR 33 United States Department of Agriculture, Forest Service, Dry Branch, Georgia
  • United States Department of Agriculture (2024). Taxodium distichum (L.) Rich. United States Department of Agriculture, [link] (accessed 2024-11-19)
  • United States Forest Service (1935). Possibilities of Shelterbelt Planting in the Plains Region US Forest Service, Lake States Forest Experiment Station, Washington, DC
  • United States National Arboretum (1999). Loropetalum chinense var. rubrum 'Blush' and 'Burgundy' [link] (accessed 2025-03-24)
  • United States National Arboretum (2023). U.S. National Arboretum Plant Introduction ×Chitalpa 'Strawberry Moon' [Factsheet] September 2023 [link]
  • Universiteit van Amsterdam (2008). Dutch Elm Disease: An Interactive Approach [link] (accessed 2008-06-08)
  • University of Alabama Division of Agriculture (ed) (2023). Plant of the Week: Zelkova schneideriana; Chinese Zelkova [link] (accessed 2023-03-11)
  • University of Arizona (2025). Fatsia japonica [link] (accessed 2025-10-28)
  • University of Bergen (2008 onwards). Arboretum and Botanical Garden Explorer [link] (accessed 2021-05-05)
  • University of British Columbia (2008 onwards). UBC Botanical Garden - Garden Explorer [link] (accessed 2019-06-28)
  • University of British Columbia (2014). Meliosma oldhamii [link] (accessed 2022-02-22)
  • University of British Columbia Botanical Garden (2022). Carrierea calycina [link] (accessed 2022-02-10)
  • University of California Botanical Garden (2019). Plant Collection database [link] (accessed 2019-06-28)
  • University of California Botanical Gardens at Berkeley (ed) (2018). Univeristy of California Botanical Garden at Berkeley - Online Collections Search [link] (accessed 2018-12-06)
  • University of California, Davis (2013 onwards). Walnut Rootstock & Scion Selection Fruit and Nut Research and Information (accessed 2019-09-12)
  • University of Connecticut (2024). University of Connecticut Plant Database [link] (accessed 2024-06-21)
  • University of Copenhagen (2023). The Arboretum in Hørsholm: Turkish Hazel [link] (accessed 2023-02-04)
  • University of Copenhagen (ed) (2018-). The Arboretum in Hørsholm The Arboretum in Hørsholm - plant collection list (accessed 2018-12-08)
  • University of Guelph (2008 onwards). Arboretum Explorer [link] (accessed 2020-02-20)
  • University of Liverpool (2020 onwards). Ness Botanic Gardens [link] (accessed 2020-06-30)
  • University of Manchester (2020 onwards). Jodrell Bank Arboretum Jodrell Bank Discovery Centre (accessed 2020-06-30)
  • University of Melbourne (1995–2020). Sorting Prunus names [link] (accessed 2008-04-29)
  • University of Missouri Integrated Pest Management (ed) (2022). The Nut with Two Names [link] (accessed 2023-01-27)
  • University of Nebraska–Lincoln (2023 onwards). Maxwell Arboretum [link] (accessed 2023-11-28)
  • University of Oslo Botanic Garden (2024). + Laburnocytisus adamii [link] (accessed 2024-09-05)
  • University of Oslo Botanical Garden (2023). Corylus ferox [link] (accessed 2023-02-10)
  • University of Trieste (2022). Dryades Project [link] (accessed 2022-02-22)
  • University of Utah (2025). Umbrella Catalpa: Catalpa bignonioides 'Nana' [link] (accessed 2025-07-19)
  • University of Washington Botanic Gardens (2019). Living Collection search [link] (accessed 2019-06-28)
  • University of Washington Botanic Gardens (ed) (2018). Washington Park Arboretum - Living Collection Search University of Washington, [link] (accessed 2018-09-03)
  • Unser Garten (2023). Haselnüsse [link] (accessed 2023-02-01)
  • Upendranath, K. (1927). Forest Flora for the Chakrata, Dehra Dun and Saharanpur Forest Divisions Third Edition Manager of Publications, Government of India., Calcutta, Internet Archive (accessed 2025-07-19)
  • Uphof, J.C.T. (1922). Ecological Relations of Plants in Southeastern Missouri in American Journal of Botany 9:1 1-17 JSTOR (accessed 2025-07-02)
  • Upshoot (2012). Cornus racemosa – Counties of Ohio™ Series of Gray Dogwood [link] (accessed 2025-12-23)
  • Upson, T. (2013). Emmenopterys henryi - do you know the origin of your plant? [link] (accessed 2019-04-12)
  • Urban, I. et al. (2018). Hybrid walnut (Juglans Mj209) for timber production in an agroforestry scheme, some experiences learnt in Spain in 4th European Agroforestry Conference: Agroforestry as Sustainable Land Use. 28-30 May 2018 Nijmegen, The Netherlands [link] (accessed 2019-09-11)
  • Urdampilleta, J.D., Ferrucci, M.S. & Vanzela, A.L.L. (2005). Karyotype differentiation between Koelreuteria bipinnata and K. elegans ssp. formosana (Sapindaceae) based on chromosome banding patterns 149 451-455
  • Urosov, B. M. (1985). Species separation of Acer tschonoskii and Acer komarovii (Aceraceae) 70:5 666-671 in Botanicheskii Zhurnal
  • US Department of Agriculture, Division of Botany (1898-1905). Inventory No. 1 - Inventory of Foreign Seeds and Plants imported by the section of seed and plant introduction, Number 3123 p.51 Biodiversity Heritage Library (accessed 2025-11-02)
  • US Fish & Wildlife Service (2023 onwards). Species [link] (accessed 2023-04-10)
  • US Forest Service (1999). How to identify, prevent, and control Oak Wilt [link] (accessed 2008-12-23)
  • US National Arboretum (1999). Thuja ‘Green Giant’
  • US National Arboretum (2007). Treasuring the Rare and Unusual: Cornus florida L subsp. urbiniana (Rose) Rickett [link] (accessed 2008-03-22)
  • US National Arboretum (2019). online records database [link] (accessed 2019-06-28)
  • US National Arboretum (2022 onwards). Plant introductions and releases [link] (accessed 2022-01-18)
  • US Office of Foreign Seed and Introductions (1922). Checklist of plants ready for experimenters Biodiversity Heritage Library (accessed 2025-11-01)
  • US Patent and Trade Office (1994). Enkianthus Perulatus Cv. `J. L. Pennock` [link] (accessed 2022-10-06)
  • US Patent Office (2007). USPTO Full Patent and Image Database: PP17, 767 [link] (accessed 2008-05-10)
  • US Plant Patents (2014). Forsythia 'Minfor6'
  • USDA (1918). INVENTORY OF SEEDS AND PLANTS IMPORTED BY THE OFFICE OF FOREIGN SEED AND PLANT INTRODUCTION DURING THE PERIOD FROM OCTOBER 1 TO DECEMBER 31, 1915. 60
  • USDA (1923). Inventory of seeds and plants imported by the office of foreign seed and plant introduction during the period from January 1 to March 31, 1920. [link] (accessed 2018-08-20)
  • USDA (2003). USDA Plant Hardiness Zone Map, 2003 online version [link] (accessed 2008-11-22)
  • USDA (2016). NCGR-Corvallis Corylus Catalog: Eastern Filbert Blight Resistant Genotypes [link] (accessed 2023-01-29)
  • USDA (2021). Alnus rubra plant profile United States Department of Agriculture, [link]
  • USDA (ed) (2023). Fire Effects Information Service: Corylus americana [link] (accessed 2023-01-29)
  • USDA Bureau of Plant Industry (1915). Inventory of Seeds and Plants Imported by the Office of Foreign Seed and Plant Introduction During the Period from January 1 to March 30, 1913 (No. 34. Nos 34728 to 35135) Government Printing Office, Washington, DC, [link]
  • USDA Forest Service (2003). Coram Experimental Forest [link] (accessed 2008-07-26)
  • USDA Forest Service (2008). Index of species information: Chamaecyparis lawsoniana [link] (accessed 2008-03-22)
  • USDA Natural Resources Conservation Service (2015). Release Brochure for 'Ruby’ red osier dogwood (Cornus sericea ssp. sericea L.) Big Flats Plant Materials Center, Corning, New York, [link] (accessed 2026-01-07)
  • USDA Plants Database (2008). USDA Natural Resources Conservation Service PLANTS Database [link] (accessed 2008-08-14)
  • USDA [United States Department of Agriculture] (1941). Plant material introduced by the Division of Foreign Plant Introduction Bureau of Plant Industry, April 1 to June 30, 1936 (Nos. 114314–116965) Inventory No. 127 United States Department of Agriculture, Washington, DC
  • USDA/ARS, National Genetic Resources Program (2008 onwards). Germplasm Resources Information Network (GRIN) online database [link] (accessed 2008-03-22)
  • USDA–APHIS (2008). Plant Health: Lacey Act [link] (accessed 2008-11-26)
  • Usher, J.M. (2021). About Cecil Polhill The Polhilll Collection Online (accessed 2021-03-31)
  • Uzun, A. & Galalaey, A. M. K. (2022). Zelkova carpinifolia (Ulmaceae), a relict tree, first recorded in Iraq in Folia Geobotanica [link] (accessed 2023-03-10)
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
_
_
_
_
_
_

Contact the editors at