green ▁cat kins ▁produced ▁in ▁spring . ▁They ▁are ▁wind - pol lin ated ▁and ▁self - in compatible . ▁The ▁fruit ▁is ▁a ▁glo bose ▁or ▁o val ▁nut , ▁ ▁long ▁and ▁ ▁diameter , ▁en closed ▁in ▁a ▁four - val ved ▁hus k , ▁which ▁spl its ▁open ▁at ▁m atur ity . ▁The ▁nut ▁shell ▁is ▁thick ▁and ▁b ony ▁in ▁most ▁species , ▁and ▁thin ▁in ▁a ▁few , ▁not ably ▁the ▁pec an ▁( C . ▁ill ino in ensis ); ▁it ▁is ▁divided ▁into ▁two ▁hal ves , ▁which ▁split ▁apart ▁when ▁the ▁seed ▁germ in ates . ▁ ▁Et ym ology ▁The ▁name ▁" h ick ory " ▁is ▁from ▁a ▁Native ▁American ▁word , ▁from ▁the ▁Alg on qu ian ▁or ▁perhaps ▁the ▁Pow hat an ▁language . ▁It ▁is ▁a ▁short ening ▁of ▁po cker ch ic ory , ▁poc oh ic ora , ▁or ▁a ▁similar ▁word , ▁which ▁may ▁be ▁the ▁name ▁for ▁the ▁h ick ory ▁tree ' s ▁nut , ▁or ▁may ▁be ▁a ▁mil ky ▁drink ▁made ▁from ▁such ▁n uts . ▁The ▁genus ▁name ▁C ary a ▁is ▁, ▁k á ry on , ▁meaning ▁" nut ". ▁ ▁Species ▁and ▁classification ▁The ▁genus ▁C ary a ▁is ▁in ▁the ▁wal nut ▁family , ▁Jug land aceae . ▁In ▁the ▁AP G ▁system , ▁this ▁family ▁is ▁included ▁in ▁the ▁order ▁F ag ales . ▁Several ▁species ▁are ▁known ▁to ▁hy brid ize , ▁with ▁around