Jaumea carnosa   Salty Susan   (Southern)

Juglans californica   Black Walnut   (Statewide)

Juncus acutus   Spiny Rush   (Southern, Central)  

Juncus dubius   Mariposa Rush   (Statewide)   

Juncus effusus   Pacific Rush   (Statewide)  

Juncus mexicanus   Mexican Rush   (Statewide)

Juncus patens   Wire Grass   (Statewide)

Juncus species   Rush   (Statewide)

Juncus xiphoides   Iris-Leaved Rush

Juniperus californica   California Juniper   (Statewide)

Justicia californica   Chuparosa   (Southern)

Justicia californica 'Candelita'   Candelita Chuparosa   (Horticultural)

Keckiella antirrhinoides   Yellow Bush Penstemon   (Southern)

Keckiella cordifolia   Climbing Bush Penstemon   (Southern)

Keckiella ternata   Summer Bush Penstemon  (Southern, Baja California) 

Koeleria macrantha   June-grass   (Statewide)

Larrea tridentata Creosote Bush   (Southern)

Lasthenia californica   Goldfields   (Statewide)

Lavatera assurgentiflora   Tree Mallow   (Southern)

Layia platyglossa   Tidy Tips    (Statewide, Baja California)

Lepichinia fragrans   Fragrant Pitcher Sage   (Southern, Channel Islands)

Lepichinia ganderi   Gander's Pitcher Sage   (Otay Mesa Mountains, Baja California)

Leptosyne gigantea   Channel Island Coreopsis   (Central, Channel Islands)

Leptosyne maritima   San Diego Sea Dahlia   (San Diego County, Baja California)

Lessingia filaginifolia var. californica   Carmel Aster   (Northern)

Leymus condensatus   Giant Wild Rye   (Southern, Central)

Leymus condensatus 'Canyon Prince'   Canyon Prince Giant Wild Rye   (Horticultural)

Leymus triticoides   Creeping Wild Rye   (Statewide)

Lilium humboldtii   Humboldt Lily   (Northern, Central)

Lilium pardalinum   Leopard Lily

Limonium californicum   Western Marsh Rosemary   (Statewide)  

Linum lewisii   Wild Flax

Lithocarpus densiflorus   Tanbark Oak   (Northern, Central)

Lobelia dunnii   Dunn's Lobelia   (Southern, Central, Baja California)

Lomatium lucidum   Shiny Lomatium, Biscuit Root   (Southern, Baja California)

Lonicera subspicata   Chaparral Honeysuckle   (Southern)

Lotus crassifolius var. otayensis   Otay Mountain Lotus   (Southern)

Lotus scoparius   Deer Weed   (Statewide)

Lupinus albifrons   Shrub Lupine   (Northern?)

Lupinus bicolor   Dove Lupine   

Lupinus chamissonis   Dune Lupine   (Statewide Coast)

Lupinus excubitus   Grape Soda Lupine   (Southern)

Lupinus truncatus   Collar Lupine   (Southern, Central, Baja California)

Lycium andersonii   Southern Boxthorn   (Statewide?)

Lycium californicum   Coastal Boxthorn   (Southern)

Lyonothamnus floribundus ssp. asplenifolius   Fern-leaved Catalina Ironwood   (Southern)

Malacothamnus fasciculatus   Chaparral Mallow   (Southern)

Malosma laurina   Laurel Sumac   (Southern)

Mammillaria dioica   Fishhook Cactus   (Southern)

Marah macrocarpus   Wild Cucumber

Melica imperfecta   Coast Range Melic   (Northern, Southern)

Mimulus aurantiacus   Bush Monkeyflower   (Southern, Central)

Mimulus cardinalis   Scarlet Monkeyflower   (Statewide)

Mimulus guttatus   Seep Monkey Flower   (Statewide)  

Mimulus longiflorus   Sticky Monkeyflower   (Southern, Channel Islands, Baja California)

Mirabilis laevis (Mirabilis californica)   Wishbone Bush   (Southern, Central)

Monanthochloe littoralis   Shoregrass   (Southern Salt Marshes)

Monardella macrantha   Red Monardella   (Southern, Central, Baja California)

Monardella nana   Yellow Monardella   (Southern, Baja California)

Monardella odoratissima   Mountain Pennyroyal   (Southern)

Monardella villosa   Coyote Mint   (Statewide)

Monardella viminea   San Diego Willowy Mint   (Southern)

Muhlenbergia rigens   Deergrass   (Statewide)  

Myrica californica   Pacific Wax Myrtle   (Northern, Central)