What is "donkey's tail"

donkey's tail \donkey's tail\ n. a Mexican plant ( Sedum morganianum) bearing small rose-colored flowers; called also burro's tail, horse's tail, and lamb's tail.
--RHUD

Donkey's Tail was a Russian artistic group created from the most radical members of the Jack of Diamonds group. The group included such painters as: Mikhail Larionov (inventor of the name), Natalia Goncharova, Kazimir Malevich, Marc Chagall, and Aleksandr Shevchenko. The group was influenced by the Cubo-Futurism movement. The only exhibition of the group took place in Moscow in 1912. In 1913, the group fell apart.