What does ancipital or ancipitous mean?
The definition of ancipital and ancipitous
An*cip”i*tal, An*cip”i*tous, a.
Etym: [L. anceps, ancipitis, two- headed, double; an- for amb- on both sides + caput head.] (Bot.)

Two-edged instead of round; — said of certain flattened stems, as those of blue grass, and rarely also of leaves.