amphigastrium

plural amphigastria

1. biologyA small scale-like leaf on the underside of stems of certain liverworts.

   CHILOSCYPHUS. — Plant ; portion of the stem, with involucral leaves, perianth, and calyptra ; […] portion of the stem, with a leaf and an amphigastrium

   1871, William S. Sullivant, “Explanation of the plates”, in The musci and hepaticae of the United States east of the Mississippi River, Genera of Hepaticae, page 120

   2 more examples

   Stems more or less regularly pinnate, more rarely dichotomously branched. Leaves incubous, conduplicate, the hinder lobe smallest—saccate, galeate, cucullate or flattish. Amphigastria mostly present, rarely wanting.

   1876, David Moore, “Report on Irish Hepaticæ”, in Proceedings of the Royal Irish Academy, Section II. Jungermanniaceæ, page 607

   Key to the South African species of Lejeunea. […] d. Base of the amphigastrium with rounded appendages below the insertion, the sinus of which thus is more than semicircular. L. isomorpha.

   1953, Sigfrid Arnell, “Hepaticae collected in South Africa 1951”, in Botaniska Notiser, page 271

   Synonyms: amphigaster