C. parva is a good choice, green and grassy, 2 inches tall submerged.
C. petchii (the triploid beckettii) is a nice bronze crypt that stays small enough for a 10, 5 to 6 inches tall, personal favorite of mine
C. willisii another green plant, long thin leaves, about 5 inches tall.
C walkerii only gets about 5 inches tall in my tanks, broader green leaf than willisii.
I have plants that were labled as C. lucens and C. lutea, which are synonyms of willisii and walkerii respectively, so I don't know what they are but they are small enough for a 10.
I'm getting ready to order some C. pygmaea and C. minima to see what they are like, I think they'd be the right size but I don't know how they'd hold up.
A small form of C. wendtii might be ok but could get to 12 inches tall.
C. blassii would fit, 8 to 12 inches tall.
C. moehlmannii and C. pontederiifolia would make what the oldtimers called centerpiece plants, 12 to 13 inches tall but big broad leaves like a swordplant.
C. spiralis starts out nice sized but I had some hit 16 inches in a ten gallon tank :shock: , the guy that won them at our club auction loved them.
C beckettii, C. balansae, and C. retrospiralis, no just too tall.