| P Agave sisalana (Mescal; Sisal; Hemp Plant; Sisal Agave; Sisal Hemp) |
| P Ageratum conyzoides (Mexican ageratum) |
| P Aglaonema commutatum (Aglaonema aroid) |
| P Agrimonia eupatoria (Agrimony; Sticklewort) |
| P Agrostemma githago (Corn Cockle; Cockle; Corn-Campion; Corn-Pink) |
| P Agrostistachys hookeri |
| P Ailanthus altissima (Stinktree; Tree Of Heaven) |
| P Ailanthus grandis |
| P Ajuga bracteosa (Nilkanthi) |
| P Ajuga chamaepitys (Bugle) |
| P Ajuga iva (Ivy Bugle) |
| P Ajuga remota (Bugle) |
| P Ajuga reptans (Bugle; Bugleweed; Blue Bugle; Bugleherb; Common Bugle) |
| P Akania luceus |
| P Akebia quinata (Chocolate Vine) |
| P Alangium lamarckii |
| P Albizia julibrissin (Mimosa) |
| P Albizia procera |
| P Alchornea floribunda (Niando) |
| P Aletris farinosa (Colic Root; Star Grass; Unicorn Root; Agueroot; Crow Corn; Mealy Star Grass; Mealy Starwort) |