| Name | Structure/ Category | Description |
|---|---|---|
| Aggregate | of a flower clustered in a dense mass or head; of a fruit formed from the several separate or fused ovaries of a single flower | |
| Aggregate fruit | [Fruits] {type} | A cluster of fruits that stick together or are fused, originating from two or more separate pistils contained within a single flower, as in jackfruity (Artocarpus). |
| Alternate | [Leaves] {insertion} | Positioned singly at different heights on the stem; one leaf occurring at each node. |
| Ament | an indeterminate spicate inflorescence bearing scaly bracts and apetalous unisexual flowers (as in the willow) | |
| Androecium | A collective term for all the stamens and any closely associated structures in a flower. | |
| Angiosperm | [Plants] {major group} | Plants that bear their seeds enclosed in an ovary; the flowering plants. |
| Annual | [Plants] {life span} | Normally living one year or less; growing, reproducing, and dying within one cycle of seasons. |
| Anther | The pollen-producing portion of the stamen typically borne at the tip of a stalk or filament. | |
| Anthocarp | a fruit with some portion of the flower besides the pericarp persisting, as in a pome with the fleshy perianth tube surrounding the pericarp (h) | |
| Apex | The portion of a plant structure (such as a leaf, bud, stem, etc.) farthest from its point of attachment or uppermost; the tip. |
