Mentions of rare plants in this PDF:
...(Prosopis velutina), Desert Sand Verbena (Abronia villosa), Desert Sunflower (Geraea...
...canescens), Graythorn (Ziziphus obtusifolia), Beavertail Cactus (Opuntia basilaris), Blue...
...bigelovii), Hedgehog Cactus (Echinocereus engelmannii), Desert Agave (Agave deserti),...
...chinenis), Ratany (Krameria pavifolia), Desert Buckwheat (Eriogonum fasciculatum), Paperflower (Psilostrophe cooperi), Desert Willow Chilopsis linearis), Desert Broom (Baccharis sarothroides), Dock (Rumex hymenosepalus), Canyon Ragweed (Ambrosia ambrosioides), Desert Hackberry (Celtis pallida), Mexican Jumping Bean (Sapium biloculare), Elephant Tree (Bursera microphylla), Boojum Tree (Fouquieria columnaris), Maguey (Agave shawii), Cardon (Cereus pringelei), Ball Moss (Tillandsia recurvata), the Mexican Palo Verde (Parkinsonia aculeata), and Crucifixion Thorn (Canotia holacantha)....