Note 58 — Chapter II · WHAT MAY BE SEEN ON THE EARTH.
Reading edition
"The term perianth is usually confined to the flowers of Endogens, whatever colours they present, whether green, as in asparagus, or coloured, as in tulip. Some use the term as a general one, and restrict the use of perigone to cases where a pistil is present, not applying it to unisexual flowers, in which stamens only are produced."—Professor Balfour, "Manual of Botany," p. 169.