Castilleja subinclusa is a species of Indian paintbrush known by the common name longleaf Indian paintbrush. It is native to California and Baja California, where it grows in a number of habitat types. It is divided into two subspecies which generally do not occur together; one is widespread across the mountains of the two states, while the other is limited to the coastline surrounding the San Francisco Bay Area. In general, this is a spreading perennial herb which can exceed a meter tall. It is gray-green to purple in herbage color, and usually hairy. The lance-shaped leaves are up to 8 centimeters long. The flower cluster is up to 40 centimeters long and is made up of long, pointed leafs tipped in bright red-orange to deep red. Between the colorful leafs appear lighter flowers, which are yellow-green to pinkish and hairy.