Arnaldoa is a genus of flowering plants in the aster family, Asteraceae.

It is native to Ecuador and Peru.

[1][2] These plants are shrubs with spines located at the attachment point of each leaf to the stem.

The flower heads contain disc florets in shades of orange, orange-red, purple, or cream and the pappus-tufted fruits are adapted for wind dispersal.

The plants grow on dry, wooded or shrubby slopes at elevations between 1370 and 3000 metres.