| Haplopappus spinulosa | Goldenweed |
| § Hechtia texensis |  False Agave |
| § Hedeoma costatum | Ribbed Hedeoma |
| § Hedyotis acerosa | Needleleaf Bluet |
| § Helianthus annuus | Plains Sunflower |
| § Helianthus maximiliani | Maximilian Sunflower |
| § Helianthus petiolaris | Prairie Sunflower |
| Hesperaloe funifera | Giant Hesperaloe |
| § Hesperaloe parviflora | Red/Yellow False Yucca |
| Hesperostipa comata | Needle and Thread Grass |
| § Hesperostipa neomexicana | New Mexican Feather Grass |
| Heteropogon contortus | Tanglehead Grass |
| Heterotheca latifolia | Grass-leaved Golden Aster |
| § Heterotheca villosa | Golden Aster |
| § Hibiscus coulteri | Desert Rosemallow |
| § Hibiscus denudatus | Paleface Rosemallow |
| § Hibiscus denudatus Plant Data Sheet | Paleface Rosemallow |
| Hibiscus martianus | Heartleaf Hibiscus, Tulipan Del Monte |
| Hilaria belangeri | Curly Mesquite |
| § Hilaria mutica | Tobosa |
| Hoffmanseggia densa | Indian Hog Potato |
| § Hoffmanseggia glauca | Pig Nut |
| § Hymenoclea monogyra | Burro Bush |
| § Ipomoea coccinea | Red Morning Glory |
| § Ipomoea costellata | Crestrib Morning Glory |
| § Ipomoea leptophylla | Bush Morning Glory |
| § Janusia gracilis | Janusia |
| § Jatropha dioica | Leatherstem |
| § Jefea brevifolia | Shorthorn Zexmenia |
| § Juglans microcarpa | Texas Walnut, Little Walnut, Nogal |
| § Juniperus deppeana | Alligator Juniper |
| § Juniperus flaccida | Weeping Juniper |
| § Juniperus pinchotii | Red-berry Juniper |
| § Justica pilosella | Tube Tongue |
| § Kallstroemia grandiflora | Desert Poppy |
| § Kallstroemia parviflora | Warty Caltrop |
| § Koeberlinia spinosa | Allthorn |
| § Krameria erecta | Littleleaf Ratany |
| § Krameria lanceolata | Trailing Krameria |
| § Krascheninnikovia lanata | Winterfat |
| § Lantana urticoides | Texas Lantana |
| § Lappula redowskii | Western Stickseed |
| § Larrea tridentata | Creosotebush, Gobernadora |
| § Lesquerella gordeni | Gordon's Bladderpod |
| § Lesquerella purpurea | Rose Bladderpod |
| § Leucaena retusa | Goldenball Leadtree, Littleleaf Leadtree |
| § Leucelene ericoides | Rose Heath |
| § Leucophyllum candidum | Texas Silverleaf |
| § Leucophyllum frutescens | Texas Ranger, Ceniza, "Green Cloud" |
| § Leucophyllum laevigatum | Chihuahuan Sage |
| § Leucophyllum langmaniae | "Rio Bravo" |
| § Leucophyllum minus | Lesser Texas Silverleaf |
| § Leucophyllum pruinosum | "Sierra Bouquet" |
| § Leucophyllum revolutum | "Houdini" |
| § Leucophyllum zygophyllum | "Cimmeron" |
| § Liatris punctata | Gayfeather |
| § Linum lewisii | Blue Flax |
| § Lippia graveolens | Redbrush, Scented Lippia |
| § Lithospermum incisum | Narrowleaf Stoneseed |
| § Lobelia cardinalis | Cardinal Flower |
| § Lobelia laxiflora | Looseflower Lobelia |
| § Lonicera albiflora | Southwestern White Honeysuckle |
| § Lupinus havardii | Chisos Bluebonnet |
| § Lygodesmia texana | Skeleton Plant |
| § Machaeranthera tanacetifolia | Tansy Aster |
| § Macrosiphonia lanuginosa | Plateau Rocktrumpet |
| § Malacothrix fendleri | Fendler's Desertdandelion |
| § Malvella lepidota | Scurfymallow |
| § Mammillaria lasiacantha | Golf Ball Pincushion Cactus |
| § Mammillaria pottsii | Pott's Mammillaria |
| § Maurandya antirrhiniflora | Roving Sailor, Snapdragon Vine |
| § Maurandya wislizenii | Baloonbush |
| § Melampodium leucanthum | Blackfoot Daisy |
| § Menodora longiflora | Showy Menodora |
| § Mentzelia multiflora | Stickleaf |
| § Mimosa aculeaticarpa var. biuncifera | Catclaw Mimosa |
| § Mimosa borealis | Pink Mimosa |
| § Mimulus cardinalis | Monkeyflower |
| § Mirabilis multiflora | Desert Four O'clock |
| § Mirabilis oblongifolia | Mountain Four O'clock |
| § Monarda citriodora | Lemon Beebalm |
| § Monarda fistulosa var. menthifolia | Bergamot |
| § Muhlenbergia capillaris | "Regal Mist" |
| § Muhlenbergia emersleyi | Bullgrass, "El Toro" |
| Muhlenbergia montana | Mountain Muhly |
| § Muhlenbergia porteri | Bush Muhly |
| § Muhlenbergia rigens | Deer Grass |
| § Muhlenbergia rigida | Purple Muhly, "Nashville" |
Last Update: 18 May 2008