Hydrangeas

The mophead and lace-cap varieties of H. macrophylla are the best-known varieties.

The showy flower parts are sterile florets and mopheads have these packed around the flower-head. Lace-caps have a single ring of showy outer florets. These surround a centre of fuzzy, fertile flowers, which are usually of a contrasting colour.

History
The mophead hydrangea goes back to Japan where native species with normal lace-cap flowers had been grown in gardens for hundreds of years.

At some stage one of these plants is thought to have sported, or naturally mutated, and produced spherical heads full of sterile flowers, instead of just arranged at the edge.

When these plants first reached the west in the 18th century they caused a sensation, initially being treated as tender and grown indoors.