In this article we will discuss about the anatomy of phylloclade stem.
Phyitoclade is a modified stem which appears and functions like a leaf.
Ruscus (Family – Liliaceae):
T.S. appears flat, leaf like and reveals following tissues:
Epidermis:
1. A single, epidermal layer is Present on upper as well as lower surfaces representing upper epidermis and lower epidermis.
2. A thick cuticle is present on the outer wall of the cells of both the epidermal layers.
3. Epidermal cells arc radially elongated and their continuity is broken by many stomata present on both surfaces.
4. Stomata consist of guard cells filled with chloroplasts and clear sub-stomatal chamber.
5. Central region of the material is somewhat bulged.
Chlorenchyma:
6. Immediately below the upper epidermis are present one or two layers of loosely arranged parenchymatous cells filled with chloroplasts.
7. The cells are rounded or oval in shape and leave many intercellular spaces.
Parenchyma:
8. Parenchymatous region is well developed and present next to the chlorenchyma.
9. The cells are thin wailed, loosely arranged and leave many intercellular spaces.
Vascular System:
10. Many vascular bundles are arranged in parallel series.
11. In the central bulged region of the section are aggregated few amphivasal vascular bundles surrounded by a bundle sheath.
12. A thick, sclerenchymatous bundle sheath is present around each vascular bundle.,
13. Each vascular bundle is concentric and amphivasal (phloem in the centre surrounded by the xylem).
14. Well developed, parenchyma is present in the central region.
Leafy Characters:
1. Dorsiventral symmetry.
2. Presence of upper and lower epidermal layers with stomata.
3. Central bulged region is comparable with midrib.
4. Presence of chlorenchyma below upper epulermis.
Stem-Like Characters:
1. Presence of amphivasal vascular bundles.
2. Phloem does not face towards the lower epidermal layer.
3. Parenchyma of the central bulged region is comparable with the ground tissue or pith of stem.
4. Well differentiated cortex.
Xerophytic Characters:
1. Presence of thick cuticle.
2. Sclerenchymatous bundle sheath.