MORPHOLOGICAL, ANATOMICAL AND CYTOLOGICAL STUDIES ON ENDEMIC LAMIUM PISIDICUM

Abstract

Morphological and anatomical features of endemic Lamium pisidicum R. Mill (Lamiaceae) were studied. L. pisidicum is a perennial with a taproot system. The stem is ascending to erect in position and clearly quadrangular in shape. The leaves are ovate to broadly ovate or rarely reniform in shape. Verticillasters are 2-14 flowered. The corolla is pinkish-purple to mauve and the upper lip is deeply bifid and the tube is without annulus. The stigma is bifid. The stamens are didynamus. Anatomically, spring and autumn woods are distinguishable in the root structure of the perennial taxon. There is a welldeveloped collenchymatous layer at the corners of the stem and a pith hollow in the centre. In the petiole cross-section, 1-2 layered collenchyma layer is located at the corners while 3 central vascular bundles are located in the middle and 1 vascular bundle at the petiolar wings. The leaf is bifacial. Each anther is of two thecae and each theca is of 2 pollen sacs. Pollen type is trizonocolpate and pollen shape is spheroidal. The cross-section of seed is triangular. Glandular hairs distributed on the plant species are classified into 2 main types, peltate and capitate. Furthermore, capitate glandular hairs are seperated into 2 types, type I and type II. Somatic chromosomes are counted as 2n=18 for the first time in this study.