Yep, those are Crypt leaves. Look like probably a C. wendtii to me?
How long have you had the Crypt, and has anything - at all - changed with your tank recently? Crypts are notorious for "crypt melt" - aka throwing a temper tantrum any time anything changes. LOL
Most of the time they'll grow back just fine as long as you leave them alone.
A picture of the actual plant might help us identify if there are any nutrient deficiencies occuring, however.
How long have you had the Crypt, and has anything - at all - changed with your tank recently? Crypts are notorious for "crypt melt" - aka throwing a temper tantrum any time anything changes. LOL
Most of the time they'll grow back just fine as long as you leave them alone.
A picture of the actual plant might help us identify if there are any nutrient deficiencies occuring, however.