| Tagetes |
argentina, biflora, laxa, mendocina, perezii, riojana, rupestris |
| Tarasa |
alberti, latearistata, meyeri, trisecta |
| Tephrocactus |
alexanderi, aoracanthus, articulatus, darwinii, geometricus, halophilus, molinensis, weberi |
| Tephrosia |
fertilis |
| Tetrachondra |
patagonica |
| Tetraglochin |
acanthocarpum, paucijugatum |
| Thelypteris |
altitudinis, jujuyensis |
| Tillandsia |
albertiana, andicola, angulosa, brealitoensis, castellanii, dorotheae, friesii, genseri, guelzii, peiranoi, pfeufferi, porongoensis, retorta, tenebra, zecheri |
| Tragia |
dodencandra |
| Tragus |
andicola |
| Trevoa |
patagonica |
| Trianthema |
argentina |
| Trichocereus |
andalgalensis, angelesii, cabrerae, candicans, courantii , fabrisii, huascha, lamprochlorus, pseudocandicans, rowleyi, schickendantzii, smrzianus, strigosus, thelegonoides, thelegonus, vatteri |
| Trichocline |
boecheri, dealbata, exscapa, macrorhiza, plicata, sinuata |
| Trichopetalum |
chosmalensis |
| Trichotolinum |
deserticola |
| Tricomaria |
usillo |
| Tridens |
nicorae |
| Tripodanthus |
flagellaris |
| Trisetum |
ambiguum, bulbosum, dianthemum, longiglume |
| Tristagma |
ameghinoi, anemophilum, atruecoense, circinatum, malalhuense, nahuelhuapinum , patagonicum, sociale, spegazzinii |
| Tropaeolum |
argentinum, atrocapillare, meyeri, porifolium, slanisii, trialatum , willinkii |
| Trophaeastrum |
patagonicum |
| Tucma |
simplex |
| Tunilla |
corrugata , tilcarensis |
| Tweedia |
aucaensis, australis, echegarayi |
