Why not a pure red?
Irises flower in purple, blue, yellow, pink, orange and white, but a clean red is missing. The reason is chemical: iris pigments are built on delphinidin, while the clear red of other plants relies on a different pigment, pelargonidin. So an iris sold as red is typically burgundy, red-brown or rusty. If you meet a bright red cut iris it has very probably been dyed.
The nearest to red
The copper iris, Iris fulva, is a native of the southern and central United States. Its flowers run from coppery red to brick and rust, and it grows in swamps and ditches, often in shallow water. It belongs to the Louisiana iris group. It is reported to be frost hardy, but flowers poorly in cool summers, which is a sobering point for Irish gardens.
Searching for red iris meaning
Meaning lists differ. Iris takes its name from the Greek goddess of the rainbow, and red is traditionally a colour of passion, so a deep red iris is most often read as a gift of warm feeling. This is tradition, not fact.
Red in an Irish bouquet
Cut irises are mostly Dutch types in blue, yellow and white. To get red in a vase, pair them with another red flower, for instance a tulip or a ranunculus.
Animals
The ASPCA lists irises as toxic to dogs, cats and horses, especially the rhizomes, causing salivation, vomiting, lethargy and diarrhoea.
