Attributes / relations provided by
♦ 1i-Tree Species v. 4.0, developed by the USDA Forest Service's Northern Research Station and SUNY-ESF using the Horticopia, Inc. plant database.
♦ 2Plants For A Future licensed under a
Creative Commons Attribution 4.0 License♦ 3Wood Janka Hardness Scale/Chart J W Morlan's Unique Wood Gifts
♦ 4USDA Plants Database, U. S. Department of Agriculture
♦ 5Forest Inventory and Analysis DB version 5.1, May 4, 2013, U.S. Forest Service
♦ 6Jorrit H. Poelen, James D. Simons and Chris J. Mungall. (2014).
Global Biotic Interactions: An open infrastructure to share and analyze species-interaction datasets. Ecological Informatics.
♦ 7Sciurus griseus, Leslie N. Carraway and B. J. Verts, MAMMALIAN SPECIES No. 474, pp. 1-7 (1994)