working towards ID

When you are trying to ID an iris, you measure the stalk, is that measurement to the bottom of the bloom or to the top.?

The registered height of an iris cultivar refers to the "average" height of a stalk from the rhizome to the top of the terminal flower.

ok that explains why I have 2 purple ones that look exactly alike except for stalk height. Thank you.

I should have added that registered stalk height is determined by how the cv grows in the hybridizer's garden, which may or may not have much to do with how it ultimately grows in yours.