Plants — L
- Labisia pumila
- Lablab purpureus Hyacinth Bean
- Lactuca canadensis Canada Lettuce
- Lactuca serriola
- Lactuca virosa Acrid lettuce
- Lagenaria siceraria Birdhouse Gourd
- Laggera crispata
- Lagochilus inebrians intoxicating-mint
- Lagotis brevituba
- Laminaria Kelp
- Laminaria digitata Horsetail kelp
- Lamium album subsp. barbatum Beard white deadnettle
- Lamium amplexicaule Common Henbit
- Lamprocapnos spectabilis Asian Bleeding-heart
- Lantana Lantanas
- Lantana camara Bird's Brandy
- Lanxangia tsao-ko Tsao-ko Cardamom
- Lapsana communis Common Nipplewort
- Larix decidua Common Larch
- Laserpitium Broad-leaved Sermountain
- Laserpitium hispidum
- Lasia spinosa Spiny Lasia
- Lathyrus gmelinii
- Lathyrus humilis Short vetchling
- Lathyrus pisiformis
- Lathyrus pratensis Meadow vetchling
- Lathyrus sativus Ethiopian lentil
- Lathyrus tuberosus Dutch-mice
- Lathyrus vernus
- Laurus nobilis Bay
- Lavandula Lavender
- Lavandula angustifolia English Lavendar
- Lavandula dentata French Lavender
- Lavandula latifolia Broad-leaved Lavender
- Lavandula pubescens Downy Lavender
- Lavandula spica
- Lawsonia inermis Camphire
- Leea indica Bandicoot Berry
- Lekusku lakaska Schefflera arboricola
- Lemna minor Boggart
- Lens culinaris Lentil
- Leonotis leonurus Cape Hemp
- Leonotis nepetifolia Adonis Abbot
- Leontice leontopetalum
- Leontopodium
- Leontopodium nivale edelweiss
- Leonurus
- Leonurus cardiaca Common Motherwort
- Leonurus japonicus Chinese motherwort
- Leonurus macranthus Large-flower motherwort
- Leonurus quinquelobatus five-bladed motherwort
- Leonurus sibiricus Honeyweed
- Lepechinia calycina
- Lepidium meyenii Peruvian-ginseng
- Lepidium sativum Garden cress
- Lepisanthes fruticosa
- Lepisanthes rubiginosa
- Leptadenia reticulata leptadenia
- Leptospermum Tea Tree
- Leptospermum scoparium Broom Tea-Tree
- Lespedeza capitata Dusty-clover
- Lessertia frutescens Balloon Pea
- Leucaena leucocephala
- Leucas aspera Common leucas
- Leuenbergeria bleo Rose Cactus
- Levisticum Lovage
- Levisticum officinale Lovage
- Leycesteria formosa Himalayan honeysuckle
- Ligularia glauca
- Ligularia przewalskii Przewalski's Leopard-Plant
- Ligusticum mutellina alpine lovage
- Ligustrum lucidum Broadleaf Privet
- Ligustrum sinense
- Lilium formosanum Formosa lily
- Lilium lancifolium Devil Lily
- Limnophila aromatica Finger Grass
- Limonia acidissima Indian Woodapple
- Limonium platyphyllum Florist's Sea-lavender
- Linaria japonica Seashore toadflax
- Linaria vulgaris Butter And Eggs
- Lindenbergia muraria
- Lindera erythrocarpa Red-fruit Spicebush
- Lindera megaphylla
- Lindernia anagallis
- Linum usitatissimum
- Lippia abyssinica Koseret
- Lippia alba Bush Tea
- Liquidambar formosana Chinese Sweet Gum
- Liquidambar orientalis Oriental Sweetgum
- Liriope muscari Big Blue Lilyturf
- Liriope spicata Creeping Lilyturf
- Lithospermum erythrorhizon Purple Gromwell
- Lithospermum officinale Common Gromwell
- Lithraea molleoides
- Lobelia Giant Lobelia
- Lobelia chinensis Asian lobelia
- Lobelia inflata Indian Tobacco
- Lobelia kalmii
- Lobelia tupa devil's tobacco
- Lobostemon fruticosus Common Eightday Curebush
- Lolium temulentum Bearded Darnel
- Lomatium
- Lonicera japonica Chinese Honeysuckle
- Lophatherum gracile Common lophatherum
- Lophatherum sinense Hairy lophatherum
- Loxogramme chinensis
- Ludisia discolor
- Ludwigia hyssopifolia
- Luffa aegyptiaca Loofah, Plant sponge
- Lunaria annua Annual Honesty
- Lunaria rediviva
- Luzula capitata Sweep's woodrush
- Lycium Boxthorn
- Lycium barbarum Barbary Matrimony-vine
- Lycium chinense Chinese Teaplant
- Lycium pallidum Pale Desertthorn
- Lycopodiella inundata Inundated Clubmoss
- Lycopodium clavatum Common Club Moss
- Lycopodium japonicum
- Lycopodium lagopus Hare's-foot Clubmoss
- Lycopus americanus American Bugleweed
- Lycopus europaeus Bugleweed
- Lycopus lucidus Shiny bugleweed
- Lycopus virginicus Bugleweed
- Lycoris radiata
- Lysimachia Loosestrife
- Lysimachia arvensis
- Lysimachia christinae
- Lysimachia nummularia Creeping Jenny
- Lythrum salicaria
- Lythrum virgatum European Wand Loosestrife