ung us . ▁Hey bro ek , ▁having ▁observed ▁in ▁ 1 9 5 7 ▁its ▁wind - res istance ▁in ▁Schles wig - Hol stein , ▁included ▁Ho ers holm ▁el m ▁in ▁his ▁bre eding ▁programme ▁( see ▁' Hy brid ▁cultiv ars ' ▁below ). ▁Font aine ▁confirmed ▁it ▁a ▁useful ▁wind - break ▁tree . ▁ ▁Notable ▁trees ▁Fine ▁un pr un ed ▁spec im ens ▁stand ▁in ▁Stockholm , ▁in ▁Ra oul ▁W allen berg ▁square ▁and ▁the ▁Kar la plan . ▁ ▁Hy brid ▁cultiv ars ▁The ▁tree ▁was ▁hy brid ized ▁with ▁' Comm elin ' ▁and ▁U . ▁p um ila ▁as ▁part ▁of ▁the ▁Dutch ▁el m ▁bre eding ▁programme ▁at ▁the ▁De ▁Dor sch k amp ▁Institute , ▁W agen ingen . ▁Se eds ▁ar ising ▁from ▁the ▁crossing ▁were ▁don ated ▁by ▁Hans ▁Hey bro ek ▁to ▁the ▁University ▁of ▁Wisconsin - Mad ison ▁programme ▁in ▁ 1 9 6 0 . ▁The ▁clone ▁' Reg al ' ▁was ▁a ▁fro st - hard y ▁selection ▁from ▁the ▁result ant ▁seed lings , ▁whilst ▁the ▁later ▁ 1 9 8 4 ▁US DA ▁release ▁' Hom est ead ' ▁arose ▁from ▁the ▁crossing ▁of ▁another ▁with ▁U . ▁p um ila . ▁ ▁Syn onym y ▁Ul mus ▁car pin ifolia ▁' H o ers holm ': ▁Kr üss mann , ▁Hand buch ▁der ▁La ub geh öl ze ▁ 2 : ▁ 5 3 4 , ▁ 1 9 6 2