| Lachemilla |
asplenifolia, grisebachiana |
| Laennecia |
altoandina |
| Lampaya |
hieronymi |
| Lantana |
entrerriensis, magnibracteata, tilcarensis, xenica |
| Larrea |
ameghinoi, cuneifolia |
| Lathyrus |
cryophilus, pastorei, tomentosus |
| Leandra |
niederleinii |
| Lecanophora |
ameghinoi, chubutensis, ecristata, heterophylla, jarae, ruizlealii, subacaule |
| Lepechinia |
sagittata |
| Lepidium |
argentinum, boelckeanum, boelckei, burkartii, filisegmentum, hickenii, johnstonii, jujuyanum, myrianthum, parodii, rhytidocarpum, santacruzensis, serratum, stuckertianum, tandilense |
| Lepidophyllum |
cupressiforme |
| Leptoglossis |
linifolia |
| Leptostelma |
meyeri, tucumanense |
| Leucheria |
amoena, candidissima, diemii, eriocephala, leontopodioides, pteropogon, purpurea, suaveolens |
| Leymus |
erianthus |
| Liabum |
candidum, eremophilum |
| Lippia |
grisebachiana, junelliana, salsa |
| Lithodraba |
mendocinensis |
| Loasa |
incurva, pulchella |
| Lobivia |
bruchii, chrysantha, crassicaulis, densispina, einsteinii, euanthema, famatinensis, formosa, gonjianii, haematantha, jajoiana, kieslingii, korethroides, marsoneri, nigricans, saltensis, sanguiniflora, schreiteri, silvestrii, vatteri , walteri |
| Lonchocarpus |
lilloi |
| Luciliocline |
catamarcensis, santanica |
| Lupinus |
alivillosus, andicola, aureonitens, austrorientalis, burkartianus, erectifolius, hieronymi, honoratus, intortus, jujuyensis, opertospicus, tafiensis, tucumanensis, ultramontanus, umidicola |
| Luzula |
antarctica, correae, mendocina, parvula, ruizlealii |
| Lycium |
ameghinoi, athium, elongatum, fuscum, gilliesianum, infaustum, pubitubum, repens, schreiteri, vimineum |
| Lycopodium |
erectum |
