Studies in the family Scrophulariaceae

Abstract

The present work deals with the floral anatomy of 20 species of the family Scrophulariaceae belonging to 10 genera of the tribe Gratioleae.

The sepals are five in number in all the members. The sepals are one-traced, three-traced or sometimes four-traced. The sepals of the same flower may show variation in the number of traces as noted inMacardonia andStemodia. The one-traced condition is assumed to have been derived from three-traced one by the reduction of two lateral traces and four-traced by the duplication of one of the three traces.

The petals are five in all members and are one-traced. The number of stamens show reduction from five to two. In certain species although the posterior stamen disappeared their ‘vascular stub’ is represented in the respective position. The various steps in reduction from five stamened to two stamened condition can be traced, through intermediary steps.

The placentation is axile inMazus andMimulus. But inStemodia, Macardonia andDeinostema, the placentation is anatomically parietal at the basal region and parietal in every way at the upper region of the ovary. InDopatrium the placentation is parietal even from the base, inLindenbergia the placentation tends to become parietal.

The secondary marginals, in the gynoecium also, show a reduction from 8 to 2.

In all instances irrespective of type of placentation and of the number of vascular bundles or strands the placentae are recognised to be composed of two ‘half placentae’. This is borne from the fact, that the ovules borne on the same placenta, are oriented in two opposite directions.