a single leaf; a single petal; a flake; a piece (of paper)
usually written using kana alone
Refers to one thin, flat, often delicate piece of something, such as a leaf, petal, snowflake, or sheet of paper. Often used in poetic or descriptive language.
一枚 (いちまい) is the standard counter for flat objects like paper, tickets, or plates. ひとひら emphasizes the delicate, poetic quality of a single thin piece, and is not used as a general counter.
花びら means 'petal' in general, while ひとひら specifically means 'one petal' and carries a more literary feel.
Etymology
Compound of ひと (one) and ひら (thin flat object, piece). The origin of ひら is uncertain, but it is a native Japanese word often used in counting thin, flat items.
