Lablab
Labrador Buttercup
Labrador Tea
Lace Grass
Lachnanthes
Lacy Phacelia
Ladyfern
Lagenaria
Lake Quillwort
Lakecress
Lakeshore Sedge
Lambsquarters
Lamiastrum
Lamp Rush
Lance Selfheal
Lanceleaf Figwort
Lanceleaf Grapefern
Lanceleaf Tickseed
Lanceleaf Wild Licorice
Lapland Sedge
Laportea
Larch
Large Beardtongue
Large Gray Willow
Large St. Johnswort
Large Toothwort
Large White Petunia
Large Whorled Pogonia
Large Yellow Loosestrife
Large Yellow Vetch
Largebract Ticktrefoil
Largebracted Plantain
Largeflower Bellwort
Largefruit Amaranth
Largefruit Blacksnakeroot
Largeleaf Goldenrod
Largeleaf Pondweed
Largeleaf Sandwort
Largepod Pinweed
Late Purple Aster
Lateflowering Goosefoot
Lateflowering Thoroughwort
Laurel
Laurel Willow