Labrador Buttercup
Lace Grass
Lachnanthes
Ladyfern
Lake Quillwort
Lambsquarters
Lamp Rush
Lance Selfheal
Lanceleaf Figwort
Lanceleaf Grapefern
Lanceleaf Tickseed
Lanceleaf Wild Licorice
Lapland Sedge
Laportea
Larch
Large Gray Willow
Large St. Johnswort
Large White Petunia
Large Whorled Pogonia
Largebract Ticktrefoil
Largebracted Plantain
Largeflower Tickseed
Largefruit Blacksnakeroot
Largeleaf Pondweed
Largepod Pinweed
Late Purple Aster
Lateflowering Goosefoot
Lateflowering Thoroughwort
Laurel
Laurel Willow
Lavender Bladderwort
Lavender Thrift
Lawndaisy
Leafy Pondweed
Leather Flower
Leatherleaf
Leathery Grapefern
Lemon Thyme
Lentil Vetch
Lespedeza
Lesser Bladderwort
Lesser Burdock
Lesser Calamint
Lesser Canadian St. Johnswort