Napiform:- Turnip-shaped
Native:- Occurring naturally in a country or region.
Naturalised:- A species that has become established in an area out­side its native distribution.
Nectary:- A nectar producing organ. Nectaries are often located at the base of a petal, in a modified petal, at the base of a stamen or in the tip of a spur or pouch. Nectar is sweet and sugary and much sought by pollinating insects.
Nectariferous:- With nectar
Node:- Points on the stem where the leaves arise; they are often regularly spaced.

Obcordate:- Heart-shaped, with the point of attachment at the narrow end.
Obdeltoid:- Triangular, with the apex truncate and tapering to the stalk
Obdiplostemonous:- Having the stamens in two whorls, the inner whorl opposite the sepals and the outer whorl opposite the petals
Oblong:- Rectangular with rounded ends - used to describe a leaf or petal shape.
Oblanceolate:- Inversely lanceolate, broadest towards the apex and tapering to the stalk.
Inversely ovate, broadest towards the apex and tapering to the stalk.
Obpyramidal:- Inversely pyramid-shaped.
Obpyriform:- Inversely pear-shaped.
Obtuse:- Blunt, not pointed, ending in an angle of between 90 - 180o
A sheath-like structure which is an extension of the leaf­stalk base and surrounding the stem just below the leaf.
Opposite:- Two leaves or other organs that arise on opposite sides of the stem and at the same level.
Orbicular:- Rounded; as wide as long.
Oval:- A broad ellipse, with rounded rather than pointed ends.
Ovary:- The female organ containing the ovules.
Ovate:- Broad and rounded at the base and tapering toward the end.
Ovate-oblong:- Rounded at the base and tapering toward the end to rectangular with rounded ends.
The organ containing the egg, which after fertilisation develops into the seed.