Lactuca undulata 
Lacy Ragweed 
Lance-leaved coreopsis 
Large Venuss-looking-glass 
Large-flowered mat daisy 
Large-flowered tickseed 
Large-leaved Aster 
Lasiocephalus ovatus 
Lasiopogon muscoides 
Late boneset 
Late Goldenrod 
Launaea angustifolia 
Launaea arborescens 
Launaea capitata 
Launaea mucronata 
Launaea spinosa 
Lavender-Cotton 
Layia glandulosa 
Leafy fleabane 
Legousia hybrida 
Legousia pentagonia 
lemon scented tarplant 
Leontodon asperrimus 
Leopard's Bane