Three ships of the British Royal Navy have been named HMS Ivy named after the plant.
The first Ivy was an sloop but renamed before her launch in 1915. The second was an launched in 1917 and sold in 1920. A third Ivy was a with pennant number K204 ordered from Harland & Wolff on 8 April 1940 but cancelled on 23 January 1941.
References
U-boat net