Morphological and Anatomical Studies of Santolina chamaecyparissus L. (Asteraceae) Ii. Anatomical Characteristics and Volatile Oil

摘要

A study of two parts about various botanical aspects of lavender cotton (Santolina chamaecyparissus L.)was conducted. This is the second part of the study which is dealing with the plant structure and the volatile oilcomposition. Results are summarized as follows: Adventitious roots develop on the herbaceous stem cuttings.The epidermis consists of a single parenchymatous layer, followed by 8-9 layers of the cortex which is limitedinternally by a uniseriate endodermis. A hexaprotostele develops and secondary growth takes place in the usualmanner. The pith is absent. Apical internode of the main stem represents the primary structure. The cortexconsists of 6-7 layers. The stele includes 20 collateral bundles, each having a fiberous cap abutting the primaryphloem. Secondary growth develops in internodes of median and basal portions of the main stem. A peridermreplaces the epidermis. Secretory canals in large numbers are found in the cortex. Secondary xylem constitutes70% of secondary vascular tissues. Secondary xylem which forms through the winter season comprises a broadcylinder of xylem with small vessels arrange in radial rows surrounding the pith. Next to this distinguishedcylinder of xylem, towards the outside, larger vessels of the secondary xylem differentiating at summer seasonarrange in bands fluctuate between tangential and diagonal in orientation. Paratracheal lignified parenchymaaccompany the vessels also form tangential and diagonal bands; i.e., confluent parenchyma develops. Leaf bladeis wavey in outline, bounded by a uniseriate epidermis. Trichomes of woolly hairs type are present. Fivecollateral bundles are embedded in the ground tissue. The main large one is in the center. The petiole issomewhat flattened in shape. Trichomes are similar to those found on the leaf blade (woolly hairs). In the centerthere is a main vascular bundle (the largest one), to the right and to the left of this bundle another small bundledevelops. Volatile oil of lavender cotton is a mobile liquid of pale yellow colour having an aromatic harsh smell.At flower bud stage, the volatile oil compose 39 components decrease to 36 components at opened flowersstage. Only 22 of these components are identified since the remainder are present as traces. Santolina alcohol,1.8 – cineole and artemisia ketone are the main constituents of the volatile oil.