1Memorandum Books, 1771 (Jefferson Papers)
...Cherry. F. Cerasus. 5.—Clethra—Cockspur hawthorn, or haw. Crataegus. 4.—Laurel.—Scorpion Sena...
2Thomas Jefferson to Thomas Main, 20 January 1810 (Jefferson Papers)
agriculture; and hawthorn hedges [index entry] hawthorn [index entry]
3Thomas Jefferson to Joseph C. Cabell, 13 July 1816 (Jefferson Papers)
thinks the Cockspur hawthorn (our common one) would be preferable as being stronger...