| P Apocynum androsaemifolium (Bitterroot; Spreading Dogbane) |
| P Apocynum cannabinum (Bitterroot; Spreading Dogbane) |
| P Aquilaria agallocha (Lignum Aloe) |
| P Aquilegia vulgaris (Columbine) |
| P Arachis hypogaea (Groundnut; Peanut) |
| P Aralia cordata (Udo) |
| P Araucaria bidwillii (Monkey puzzle) |
| P Arbutus menziesii |
| P Arbutus unedo (Arbutus; Strawberry Tree) |
| P Arctium lappa (Gobo; Great Burdock; Burdock) |
| P Arctostaphylos uva-ursi (Bearberry; Uva Ursi) |
| P Ardisia japonica (Marlberry) |
| P Areca catechu (Betel Nut; Pin-Lang) |
| P Arecastrum romanzoffianum (Feathery coconut; Queen palm) |
| P Argemone mexicana (Prickly Poppy) |
| P Argyreia nervosa (Silver Morning Glory; Wood Rose) |
| P Argyreia speciosa (Elephant Creeper) |
| P Argyrocytisus battandieri |
| P Arisaema consanguineum (Chinese Jack-In-The-Pulpit) |
| P Arisaema triphyllum (Jack-In-The-Pulpit) |