It is well-known that the following three kinds of development have been working during the evolution of the inflorescence of Carex L. (Cyperaceae): reduction of inflorescence, condensation of inflorescence and fusion of inflorescence elements. The present perigynium is unanimously interpreted as the modified prophyll of an inflorescence branch. Some think that the present unisexual flower has evolved from an androgynous predecessor flower. This page presents my own observations on these items.
Carex diandra Schrank (Cyperaceae) (Finland, Lohja, Hongisto, 1989). – Image: Harri Harmaja (scanned from dried specimens). – Normal type of spike (on the left) of one plant and an untypical, multiple spike (on the right) from another, near-by plant. The perigynia are similar, and the deviating plant, too, belongs definitely to C. diandra. The multiple inflorescence apparently represents an atavism, a reborn plesiomorphic state of the inflorescence structure.
Created February 10, 2005. Latest revision November 16, 2007.