Obovate

Inversely ovate

Obtuse

Blunt (as in apex of leaf or petal)

Offset

A new plant formed from a short, rooted side-growth, which can be detached from its parent

One year budded

Having been grown for one season in a nursery plant bed after propagation

Open ground grown

Having been established and grown in the ground without protection and not grown in a container or frame

Opposite

(Leaves) borne two to each note, opposite each other

Oval

Broadest at the middle

Ovary

Basal 'box' part of the pistil, containing the ovules

Ovate

Broadest below the middle

Ovule

Female germ cell in flowering plant