The Royal Horticultural Society Botanical Lexicon and Species Index

• Aquilegia — A genus of herbaceous perennial plants in the family Ranunculaceae, popularly known as 'columbine'; these structural plants are recognized by their spectacular, rarely shaped flowers equipped with long nectar spurs, being widely utilized in decorative horticulture and studied in evolutionary biology.
• Astrophytum capricorne — A species of xerophytic plants within the Astrophytum genus (Cactaceae family), native to the semi-desert regions of Mexico (Chihuahuan Desert), characterized by a spherical stem that becomes cylindrical at maturity, divided into 7-8 sharp ribs. The species is distinguished by its long, flexible, flattened, and twisted spines reminiscent of a goat's horns (or a capricorn's), and by its large, yellow flowers with a deep purple or red center.
• Astrophytum myriostigma — A species of succulent cacti within the Astrophytum genus (Cactaceae family), native to the mountainous and arid regions of central and northern Mexico. The plant has a globose stem completely lacking spines, typically divided into 5 prominent ribs, giving it a three-dimensional star shape; its entire epidermis is densely covered by thousands of trichomes (microscopic white dots), giving it a characteristic silver-white hue, and its large flowers are pure yellow without a red center.
• Astrophytum ornatum — The largest and most vigorous cactus species within the Astrophytum genus (Cactaceae family), endemic to the canyons and limestone slopes of central Mexico (Querétaro and Hidalgo states). The plant has a spherical stem in youth that becomes columnar at maturity, capable of reaching over one meter in height; it features 8 subtly spiraled ribs, is armed with long, rigid, yellowish spines, and its epidermis is decorated with ornamental curved bands of white trichomes, bearing large yellow flowers.