Justicia americana Justicia brandegeana
Justicia brandegeana 'Variegata' Justicia californica
Kalmia angustifolia 'Royal Dwarf' Kalmia latifolia
Kalmia latifolia 'Alba' Kalmia latifolia 'Big Boy'
Kalmia latifolia 'Bullseye' Kalmia latifolia 'Carousel'
Kalmia latifolia 'Elf' Kalmia latifolia 'Freckles'
Kalmia latifolia 'Heart of Fire' Kalmia latifolia 'Heart's Desire'
Kalmia latifolia 'Keepsake' Kalmia latifolia 'Little Linda'
Kalmia latifolia 'Meteor' Kalmia latifolia 'Minuet'
Kalmia latifolia 'Olympic Fire' Kalmia latifolia 'Ostbo Red'
Kalmia latifolia 'Paul Bosley' Kalmia latifolia 'Peppermint'
Kalmia latifolia 'Pink Surprise' Kalmia latifolia 'Raspberry Glow'
Krugiodendron ferreum Laguncularia racemosa
Lantana ovatifolia var. reclinata Larix laricina
Larix occidentalis Larrea tridentata
Lasthenia californica Lavatera assurgentiflora
Layia platyglossa Leitneria floridana
Lemna gibba Lespedeza capitata
Leucaena retusa Leucophyllum candidum
Leucophyllum frutescens Leucophyllum frutescens 'Green Cloud™'
Leucophyllum pruinosa Leucophyllum zygophyllum
Leucothoe fontanesiana Leucothoe fontanesiana 'Girard's Rainbow'
Leucothoe fontanesiana 'Rainbow' Lewisia cotyledon
Lewisia cotyledon 'Ashwood Strain' Lewisia cotyledon 'Hybrid Mix'
Lewisia longipetala 'Little Plum' Leymus condensatus
Leymus condensatus 'Canyon Prince' Leymus secalinus
Liatris ligulistylis Liatris pycnostachya
Liatris spicata Liatris spicata 'Alba'
Liatris spicata 'Floristan Violet' Liatris spicata 'Kobold'
Lilium canadense Lilium columbianum
Lilium pardalinum Lilium superbum
Limnanthes douglasii Linanthus grandiflorus
Lindera benzoin Lindheimera texana
Linnaea borealis Linum lewisii
Liquidambar styraciflua Liquidambar styraciflua 'Aurea'
Liquidambar styraciflua 'Burgundy' Liquidambar styraciflua 'Festival'
Liquidambar styraciflua 'Globe' Liquidambar styraciflua 'Gumball (Lollipop)'
Liquidambar styraciflua 'Rotundiloba' Liquidambar styraciflua 'Slender Silhouette'
Liquidambar styraciflua 'Ward (Cherokee™)' Liquidambar styraciflua 'Worpelsdon'
Liriodendron tulipifera Liriodendron tulipifera 'Arnold'
Liriodendron tulipifera 'Integrifolium' Lithocarpus densiflorus
Lithocarpus densiflorus var. densiflorus Lithocarpus densiflorus var. echinoides
Lobelia cardinalis Lobelia laxiflora
Lobelia laxiflora angustifolia Lobelia siphilitica
Lobelia siphilitica 'Alba' Lonicera involucrata
Lonicera involucrata var. alpina Lonicera sempervirens
Ludwigia peploides Luetkea pectinata