Alphitonia ponderosa is a species of flowering tree in the family Rhamnaceae, that is endemic to the Hawaiian Islands. It is locally known as kauila, as is the related Colubrina oppositifolia.
Alphitonia ponderosa is a medium to large tree, reaching high with a trunk in diameter.
The alternate leaves are ovate, long, and have petioles. The leaves are shiny, hairless, and green on the top, but are a dull light green with rust-colored veins on the bottom.
Flowers of A. ponderosa are polygamous and form cymes at the bases of leaves. They are in diameter; the five sepals are and cover five petals.
The fruit of A. ponderosa is a diameter drupe, which contain two to three seeds. The seeds are shiny, oblong, and have a red covering.
Alphitonia ponderosa inhabits dry, coastal mesic, and mixed mesic forests at elevations of on all main islands, but is rare except on Kauai. It grows as a shrub on exposed ridges.
The reddish-brown wood of A. ponderosa is highly prized for its beauty, strength, and density. It was used as a replacement for metal by the Native Hawaiians, who made laau melomelo (fishing lures), (daggers), (short spears), (long spears), à Âà  (digging sticks), (round , ie kà «kà « (square beaters), (shark tooth clubs), and kii (tiki carvings) with it.
Alphitonia ponderosa is considered a vulnerable species by the IUCN because of its fragmented distribution and declining population. Major threats include rats, pigs, deer, competition with introduced species of plants, and wildfire.