| Family | Species | Environment | Priority for conservation | Genetic Resources |
| Fabaceae | Acacia bonariensis Gillies ex Hook. & Arn. | 1 |
| M |
| Asteraceae | Acanthospermum australe (Loefl.) Kuntze | 4 | OR | |
| Myrtaceae | Acca sellowiana (O. Berg) Burret | 1 | F-M-OR | |
| Asteraceae | Achyrocline alata (Kunth) DC. | 2 | M-OR | |
| Asteraceae | Achyrocline flaccida (Weinm.) DC. | 1.4 | M | |
| Asteraceae | Achyrocline satureioides (Lam.) DC. | 1.4 | M-OR | |
| Fabaceae | Adesmia bicolor (Poir.) DC. | 1 | FO | |
| Fabaceae | Adesmia latifolia (Spreng.) Vogel | 2 | FO | |
| Pteridaceae | Adiantopsis chlorophylla (Sw.) Fée | 1 | OR | |
| Pteridaceae | Adiantum digitatum Hook. | 1 | M-OR | |
| Orobanchaceae | Agalinis communis (Cham. & Schltdl.) D’Arcy | 1 | OR | |
| Sapindaceae | Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Hieron. ex Niederl. | 1 | F-M-OR-T | |
| Verbenaceae | Aloysia gratissima (Gillies & Hook.) Tronc. | 1 | M-OR | |
| Amaranthaceae | Alternanthera philoxeroides (Mart.) Griseb. | 2 | M-T | |
| Asteraceae | Ambrosia tenuifolia | 3 | M-OR | |
| Violaceae | Anchietea pyrifolia (Mart.) G. Don | 1 | M | |
| Poaceae | Andropogon lateralis Nees | 1 | OR | |
| Cyperaceae | Androtrichum trigynum (Spreng.) H. Pfeiff. | 2 | OR | |
| Pteridaceae | Anogramma sp. | 2 | OR | |
| Poaceae | Aristida sp. | 3 | OR | |
| Apocynaceae | Asclepias mellodora A. St.-Hil. | 1 | M | |
| Asteraceae | Aspilia montevidensis (Spreng.) Kuntze | 1.3 | OR | |
| Poaceae | Axonopus fissifolius (Raddi) Kuhlm. | 3 | FO | |
| Salicaceae | Azara uruguayensis (Speg.) Sleumer | 1 | OR | |
| Salviniaceae | Azolla filiculoides Lam. | 2 | OR | |
| Asteraceae | Baccharis aliena (Spreng.) Joch. Müll. | 1 | OR | |
| Asteraceae | Baccharis articulata (Lam.) Pers. | 3 | M-OR | |
| Asteraceae | Baccharis dracunculifolia DC. | 1 | OR | |
| Asteraceae | Baccharis gnaphalioides Spreng. | 4 | OR | |
| Asteraceae | Baccharis patens Baker | 1 | M | |
| Asteraceae | Baccharis punctulata DC. | 2 | OR | |
| Asteraceae | Baccharis spicata (Lam.) Baill. | 3 | OR | |
| Asteraceae | Baccharis trimera (Less.) DC. | 1.3 | M-OR | |
| Asteraceae | Baccharis vulneraria Baker | 2 | M | |
| Plantaginaceae | Bacopa monnieri (L.) Pennell | 2 | OR | |
| Fabaceae | Bauhinia forficata Link | 1 | M-OR | |
| Begoniaceae | Begonia cucullata Willd. | 1 | M-OR |