Introduction top ↑
This volume deals with the leaf venation patterns of plant families from the orders Violiales and Passifloriales. These orders have nine families and five families respectively. Leaves from five families in the Violiales and two families in the Passifloriales were collected for clearing and describing. The family Flacourtiaceae consisting of 93 genera and 1000 species was targeted many years ago for describing because of the occurrence of Banara leaves with acrodromal secondary venation in the fossil record in Washington. It was supposed that the family might have a large number of species with acrodromal secondary venation. It was somewhat surprising after clearing 312 species of the Flacourtiaceae to find that around 65% of the species had pinnate venation and only 15% or so had acrodromal venation. The leaves of 123 species of the Passifloraceae were also cleared, most of these belonging the genus Passiflora. Many of these leaves had actinodromous secondary venation. This pattern is like acrodromal venation except the secondary veins departing from base of the leaf are directed more laterally than distally as is the case in acrodromal venation. This is the first time this pattern has occured or been described in the series. It was also interesting to note that the diverse leaf shapes of Passiflora did not alter the basic patterns of secondary venation beyond description.