celtis reticulata

from The Collaborative International Dictionary of English v.0.48

Palo blanco \Pa"lo blan"co\ [Sp. blanco white.]
   (a) A western American hackberry ({Celtis reticulata}),
       having light-colored bark.
   (b) A Mexican mimosaceous tree ({Lysiloma candida}), the bark
       of which is used in tanning.
       [Webster 1913 Suppl.] Palolo