Mericarp and Seed Morphology of the genus Althaea L. (Malvaceae) in Turkey

Abstract

Macro and micromorphological characteristics of mericarps and seeds of four species belongingto the genus Althaea L. (Malvaceae) distributed in Turkey are studied via a light microscope (LM)and a scanning electron microscope (SEM) in order to identify their these features and theimportance of them as taxonomic evidence. The mericarps are light-dark brown or light yellowbrownin color and reniform or orbicular to reniform in shape. All the investigated species havewhite, stellate and pilose hairs only on the dorsal sides of mericarps except of A. cannabina andalso epicuticular wax crystalloids on the lateral sides of mericarps. The surface pattern of themericarps is reticulate-striate-ruminate at dorsal and scalariform-rugose at lateral faces. The seedsare dark brown, reniform, with rounded apex and base reniform, ranging from 1.76–2.76 mm inlength to 1.38–1.95 mm in width, glabrous, strophiolate with hilum basal in position. Four typesof seed surface ornamentation have been observed: rugulate-verrucate, striate, reticulate-striateand scalariform-rugose. A key using the mericarp and seed properties is provided to identify thestudied species. The size and indumentum of mericarp, seed size and ornamentation havediagnostic values for discriminating the species of Althaea.