[elkhornsloughctp.org] Habitat: Dudley?s lousewort (Pedicularis dudleyi) is found in partly shaded banks and terraces, often in rocky soil, in coastal forests dominated by coast redwood (Sequoia sempervirens), Douglas-fir (Pseudotsuga menziesii var. menziesii), and tan oak (Notholithocarpus densiflorus var. densiflorus), almost always in areas with a low density of understory plants and a thin layer of leaf litter. (link added by Mary Ann Machi)