What is "ochrea"

Ochrea \O"chre*a\, n.; pl. Ochre[ae]e. [L.]

1. (Antiq.) A greave or legging.

2. (Bot.) A kind of sheath formed by two stipules united round a stem.

n. 1 (context botany English) (alternative form of ocrea English) 2 (context historical English) A greave or legging.

An ochrea ( Latin ocrea, greave or protective legging), also spelled ocrea, is a plant structure formed of stipules fused into a sheath surrounding the stem, and is typically found in the Polygonaceae.

In palms it denotes an extension of the leaf sheath beyond the petiole insertion.