FLOWERING BEHAVIOUR OF THE MONOCARPIC PERENNIAL CYNOGLOSSUM OFFICINALE L.

Abstract

Flowering in Cynoglossum officinale L. is strongly size‐dependent. The probability of flowering increases with the size of the plant. Also, a critical size exists below which the plants do not flower. Plants above this size develop flower primordia during a cold period. During winter it is determined which plants will flower in the following spring and which plants will not. The probability of flowering is not affected by nitrogen concentration in the plant or light intensity, when these factors are separated from their effects on the dry weight of the plant. Delay of flowering is a common phenomenon in natural populations of Cynoglossum officinale on coastal sand‐dunes at Meijendel (near The Hague, The Netherlands). Over a seven‐year period the percentage flowering of rosettes varied between 2 and 25 %. The proportion of rosettes flowering was positively correlated with rainfall in the previous year and was reduced after a very cold winter. Copyright © 1986, Wiley Blackwell. All rights reserved