Runcinia acuminata is a species of crab spiders.
Females reach a body length of about 10 mm, males less than 6 mm. They are often found in seeding heads of grasses, where the females build and camouflage their egg sacs. They mainly feed on moths that visit these grasses.http://thebegavalley.org.au/11210.0.html
This species is known from Bangladesh to Japan, Borneo, New Guinea and Australia (New South Wales and Queensland).
The species name is derived from Latin acuminatus "pointed".