Hawaiʻi alectryon (Alectryon macrococcus)
Fewer than 300 Alectryon macrococcus plants remain in the wild, and the population has been steadily declining due to invasive species, habitat destruction and fire. Rats and seed-boring insects are known pests as they eat the seeds, according to the University of Hawaii. Grazing cattle or deer have also kept the tree's population limited.
This slow-growing tree is endemic to the Hawaiian islands and listed as critically endangered on the IUCN Red List. In its name, macrococcus is from the Greek macrococca, which means having large fruit, referring to the large arils this species produces.