Loculicidal dehiscence of superior and inferior capsular fruits in Myrtales

Abstract

In the representatives of the order Myrtales, the patterns of fruit dehiscence of the most common fruit – loculicidal capsule were revealed. The characteristics of capsular fruits in the studied species of Lythraceae, Myrtaceae and Onagraceae fami­lies are prominent central column, bearing seeds, and hypanthium adjoined or adnated to the ovary. Fruit dehiscence is provided by means of two kinds of longitudinal splits – dorsal and septifragal. Dorsal splits appear along the dorsal carpellary veins, while septifragal splits appear in the places where septae detach from the central column. Studied species differ in the ovary position: in Heimia salicifolia L. (Lythraceae) ovary is superior, in Callistemon macropunctatus Court. and Leptospermum scoparium Forst. (Myrtaceae) it is partly inferior, and in Oenothera biennis L. (Onagraceae) it is inferior. Since some differences were detected in the location of the dorsal dehiscence splits: in Lythraceae and Myrtaceae splits appear in the carpellary tissue only, but in Onagraceae they appear in the ovary wall of the complex origin (which is constructed by carpellary and hypanthial tissues). It was proposed to precise the fruit types and dehiscence types of studied species and to apply them: dorsally-septifragal capsule with superior (Lythraceae, Myrtaceae) or inferior (Onagraceae) dehiscence types.

Keywords

• inferior ovary
• septifragal capsule
• Lythraceae
• Myrtaceae
• Onagraceae