"Ornamental purposes" refers to using something primarily for decorative or aesthetic reasons rather than functional or practical ones. Full definition
Although grown for ornamental purposes in the United States, all species of hostas are edible and are commonly grown as vegetables in some Asian cultures. (howtogeek.com)
Mineral gypsum (selenite) has been used extensively for building and ornamental purposes in the Minoan Palace of Knossos. (european-mrs.com)
The Pie Pumpkin is used primarily for baking, but also for ornamental purposes when decorating tables or outdoor settings. (healthytraditions.com)