Field book of western wild flowers, New York, 1915, identification, west US, wildflowers, Margaret Neilson Armstrong, Margaret Neilson Armstrong, women in science, The illustration features two distinct species of verbena. At the top, the Wild Verbena (V. arizonica) is depicted with a slender, upright stem showing clusters of small, delicate flowers. Below it, the Common Vervain (Verbena prostrata) is represented with a low-growing, sprawling form, adorned with broader leaves and smaller flowers. Both species are characterized by their distinct leaf shapes and arrangements, highlighting the diversity found within the verbena genus. The detailed rendering emphasizes key botanical features, making it suitable for educational purposes in plant identification or botanical studies.