Cylindropuntia echinocarpa

Structure and habitat

A short woody axis branches into upward-curving segments about 2–3 cm in diameter. Spines with pale sheaths give the plant a silvery appearance, the source of the English name silver cholla. The field review described sites in the Mojave and Colorado deserts, usually at about 300–1400 m. [Braun and Lortie 2025]

Flowering in the study region occurs in April and May, and fruits are dry and spiny. Seed reproduction contributes substantially to regeneration. Plants can also form from detached segments. The older name Opuntia echinocarpa occurs in floristic literature. [Braun and Lortie 2025] [2-WWW]

Nectaries in young areoles

Extrafloral nectar forms near developing vegetative and reproductive organs. In the Granite Mountains study, eight ant species were observed, dominated by Crematogaster depilis and Solenopsis xyloni. Natural herbivores included the bug Chelinidea vittiger. [Braun and Lortie 2025]

The supplementary-food experiment

In 2023 and 2024, half of the 60 and 80 plants examined, respectively, were offered honey solution as an additional source of water and sugars. The treatment increased abundance of some ants and changed resource partitioning between species. Increasing bug numbers during observation concerned mainly control plants. [Braun and Lortie 2025]

The presence of C. depilis was associated with fewer herbivores and more seeds per fruit. S. xyloni showed a different pattern of relationships. The supplementary-food treatment itself did not significantly increase seeds per fruit. The results separate ant attraction, reduced feeding and the final reproductive effect. [Braun and Lortie 2025]

Place in the species comparison

Nearby, C. acanthocarpa, which produces extrafloral nectar, and C. ramosissima, which lacks this nectary type, were also studied. Comparing these three chollas allows ant-community composition to be considered in relation to availability of a specific food, plant architecture and habitat conditions. [Braun and Lortie 2025]