| Name | Structure/ Category | Description |
|---|---|---|
| Apical | [Placentation] {type} | Attachment of ovules at the top or apex of the ovary. |
| Apiculate | [Leaf apices, Leaflet apices, Petal apices, Phyllary apices, Sepal apices] {shape} | Ending abruptly in a small, slender, point that is not stiff and often slightly curved. |
| Apocarpous | having the carpels of the gynoecium separate | |
| Apopetalous | [Corolla] {fusion} | With petals distinct, not fused. |
| Apophysis | The outer portion of a cone scale which is exposed when the cone is closed. | |
| Aposepalous | [Calyx] {fusion} | With sepals distinct, not fused. |
| Appressed | [Leaves, Petals, Phyllaries, Sepals] {vertical orientation} | Pressed upwardly close or flat against the bearing structure, thus more or less parallel to it. |
| Aquatic-emergent | [Plants] {habit} | Growing in water with stem and leaves extending above the surface. |
| Aquatic-floating | [Plants] {habit} | Growing in water with leaves floating on the surface. |
| Aquatic-submerged | [Plants] {habit} | Growing in water with stem and leaves beneath the surface. |
