Kenzan
A heavy metal base set with upright pins, used to hold stems in place in a shallow container.
Also: pin frog, needle holder
Kenzan means sword mountain in Japanese. It is a lead or other heavy metal plate covered with sharp brass or steel needles. The arranger presses each stem onto the pins, or between them, and the weight of the base keeps everything steady at the angle chosen. It sits under water in a shallow dish and is the standard support for moribana. Florists elsewhere use it as a reusable alternative to floral foam.