Perennial Monocot Stem: Acorus Rhizome
cross section: Acorus calamus
common name: Sweet Flag
magnification: 40x
Berkshire Community College Bioscience Image Library
The rhizomes, or horizontal stems, of Acorus are notable for their accumulation of aromatic medicinal oils.
The well cutinized epidermis is uniseriate showing radially elongated cells with thickened outer walls and occasional corky zones.
The cortex consists of an outer hypodermis of 3-5 layers of densely packed collenchyma cells. Beneath the hypodermis lies a wide zone of starch containing parenchyma cells with numerous intracellular spaces. These spherical cells form a tight network with vascular bundles and small fiber bundles positioned at the junctions of the network.
The boundary between the cortex and stele is marked by well-defined endodermis of one layer of thick walled barrel shaped starch contain cells. A casparian strip may be evident in some preparations.
As in the cortex, the parenchymatous cells of the stele are arranged in tight aerenchymatous chains. The vascular bundles within the stele are wrapped in bundle sheaths and form a nearly continuous ring just beneath the endodermis. Unlike those situated in the cortex, these bundles are rarely associated with fibers.
Both cortical and stelar vascular bundles are leptocentric, or amphivasal, meaning xylem and phloem are arranged in concentric rings with phloem to the inside and xylem to the outside of the bundle.
Scattered throughout the cortex and stele are clear or yellowish cells containing aromatic oils, dark brown staining tannins and polygonal crystals of calcium oxalate.
Technical Questions:bioimagesoer@gmail.com
Perennial Monocot Stem: Acorus Rhizome
cross section: Acorus calamus
common name: Sweet Flag
magnification: 40x
Berkshire Community College Bioscience Image Library
The rhizomes, or horizontal stems, of Acorus are notable for their accumulation of aromatic medicinal oils.
The well cutinized epidermis is uniseriate showing radially elongated cells with thickened outer walls and occasional corky zones.
The cortex consists of an outer hypodermis of 3-5 layers of densely packed collenchyma cells. Beneath the hypodermis lies a wide zone of starch containing parenchyma cells with numerous intracellular spaces. These spherical cells form a tight network with vascular bundles and small fiber bundles positioned at the junctions of the network.
The boundary between the cortex and stele is marked by well-defined endodermis of one layer of thick walled barrel shaped starch contain cells. A casparian strip may be evident in some preparations.
As in the cortex, the parenchymatous cells of the stele are arranged in tight aerenchymatous chains. The vascular bundles within the stele are wrapped in bundle sheaths and form a nearly continuous ring just beneath the endodermis. Unlike those situated in the cortex, these bundles are rarely associated with fibers.
Both cortical and stelar vascular bundles are leptocentric, or amphivasal, meaning xylem and phloem are arranged in concentric rings with phloem to the inside and xylem to the outside of the bundle.
Scattered throughout the cortex and stele are clear or yellowish cells containing aromatic oils, dark brown staining tannins and polygonal crystals of calcium oxalate.
Technical Questions:bioimagesoer@gmail.com