Iris (Reuleaux triangle)

Description:

'..Irises are perennial herbs, growing from creeping rhizomes (rhizomatous irises) or, in drier climates, from bulbs (bulbous irises)...' wikipedia There are up to 300 species of Iris.

Habitat:

Worldwide

Notes:

Mathematics. I'm sure it's coincidental but this shape is very close to a 'Reuleaux triangle' - the only shape other than a circle with a constant diameter right the way round. It is sometimes used in engineering for this reason. Read more about this strange but useful shape here http://en.wikipedia.org/wiki/Reuleaux_tr...