Brown and Drab Flowers Shown here are southeastern Arizona plants with conspicuous brown or drab flowers. Agave palmeri – Palmer's Century Plant Ambrosia ambrosioides – Ambrosia Leaf Bur Ragweed Ambrosia confertiflora – Weakleaf Bur Ragweed Ambrosia cordifolia – Tucson Bur Ragweed Ambrosia deltoidea – Triangle Bur Ragweed Anisacanthus thurberi – Thurber's Desert Honeysuckle 1 of 31>Last