Subalpine. Scree. Summer.
Owens Basin Trail, June 13, 2004.

These lacy ferns are found in rock scree crevices.  Look for them as you walk through scree and talus slopes and rocky hillsides at higher elevations.  Notice the two distinct types of fronds: the lower, rounded lobed fronds are sterile; the taller are fertile.

"Cryptos" is Greek for "hidden" and "gramma" for "line", and taken together the two refer to lines of sporangia hidden by the rolled leaf margins.  "Acrostichoides" means that the plant is similar to plants of the genus Acrostichum.  (The Greek "oides" means "similar to").