sentences:  The perfect, apetalous wind-pollinated flowers appear in late February; the tree begins flowering at the age of five years in Italy.The sessile samarae are ovate, 14 × 17 mm.Tested by inoculation with the pathogen, 'Arno' displayed a good resistance ('4 out of 5') to Dutch Elm Disease, comparable with 'Lobel' and Plantyn'.