With a straight trunk and compact branches, Gleditsia triacanthos var. inermis ‘Skyline’ has an upright form that makes it an ideal choice for limited spaces, as either a shade or specimen tree. Its leaves turn a golden color in the fall and remain that way for an extended period. Gleditsia triacanthos var. inermis ‘Skyline’ is able to withstand hot and cold temperatures, as well as drought conditions, making it a good option for street planting. It produces small, green-yellow flowers in the middle to late part of spring and is also a thornless variety. Gleditsia triacanthos is deciduous and native to North America. Learn more about Gleditsia triacanthos. Gleditsia triacanthos var. inermis ‘Skyline’ originated in North America in 1957.