Answer: Thornless roses were first bred by Niels E. Hansen, Emeritus Professor of Horticulture, South Dakota State College, Brookings, South Dakota. He devoted his career to originatating roses without thorns.
The thornless roses come from two species: Rosa blanda of eastern Canada and from New York west to the Dakotas and Manitoba. The other is Rosa pendulina (alpina) of the Alps of Europe. His first Rosa blanda hybrid was Tetonkaha, introduced in 1912, but it was not thornless. Many more Rosa blanda hybrids have appeared since then. The 100 percent thornless ones are Pax Amanda, Pax Apollo and Pax Iola, all introduced in 1938. The best double pink so far is Lillian Gibson, introduced in 1938, but not quite thornless.
Zitkala was introduced in 1942 as a "hardy double thornless red rose." The wood is smooth except for some weak bristles and a very few small thorns near the base of the main shoots. It is not quite a Pax rose, as the Pax roses should be completely unarmed. Its flowers are a brilliant velvety red, nearly three inches across with twenty-five petals. The plant of strong upright habit is typically Rosa blanda with red bark. (Zitkala is the Teton Sioux Indian word for "bird" and both a's are pronounced as in "father.") It was produced by pollinating Rosa blanda from Bonanza Springs, western Minnesota, on the east shore of Bigstone Lake, with pollen from Amadis, or Crimson Boursault (a form of Rosa alpina) an old English rose with deep crimson-purple flowers.
Because the species hails from Canada and the European Alps, thornless roses will grow in Nebraska without problem. Here's a partial list of thornless roses:
Madame de Sancy de Parabere
Mrs. John Laing
Reine des Violettes
Rose Marie Viaud
Q&A Library Searching Tips