Frogs Forever First Class Postage Stamps

Four North American frogs - the Pacific tree frog, the northern leopard frog, the American green tree frog and the squirrel tree frog - illustrated by Nancy Stahl in a green palette with touches of brown, with William J. Gicker as art director. They were issued in July 2019 out of Boise. Stahl drew each one so the identifying features survive being shrunk to stamp size, which is the whole difficulty with amphibians: at an inch across, four green frogs can easily become one green frog.

The northern leopard frog is the one most people will recognize, spotted, five inches at most, state amphibian of both Minnesota and Vermont, capable of a five-foot zigzag leap and of slowing its own heartbeat to sit out a winter on a pond bottom. Nature centers, herpetology programmes and biology teachers buy these; so do parents of kids in the frog phase. Booklets of 20, four designs, five of each.