Magellum triangulare

The delta tree, and its close relative the unidelta tree, both have most unusual leaves that resemble from a distance the 16th century triangular shaped helmet worn by Spanish infantry. Up close, however, the leaves resemble the body of a ray, a cartilaginous marine fish found on earth. Like the ray, delta tree leaves are highly poisonous, with toxin-containing glands on their undersides. Humans on Pandora quickly learn not to rest underneath one of these trees within the range of falling leaves. (Read more)
The Na’vi use many parts of the delta tree, although harvesting them can be quite dangerous. Large stems are cleaned of their spines and carved into elaborate totems, while small stems are used to make walking sticks. Na’vi carvers sometimes leave a few clusters of spines near the bottom of a walking stick to give it dual purpose—taking a walk and snagging a small animal for dinner at the same time.

Like many plant metabolic compounds, the toxin found in leaves of the delta tree serves as a defense against herbivores that would eat the fleshy leaves to obtain water. The Na’vi have learned to strip off the lower leaf epidermis, which contains the poison glands, and harvest the tasty insides of the leaves. The non-poisonous prop roots are peeled, ground up, and used for flour in cooking.