Anatomy of leaf and stem of cycas

Anatomy of leaf of cycas
Stem of cycas

1. SAVITRIBAI PHULE PUNE UNIVERSITY

2. Department of Education and extension Name – Harshada Balasaheb shewale Subject-Botany Teacher name- Ms.priti bhalekar

3. Topic- anatomy of stem and leaf of cycas

4. Anatomically leaf is differentiated into :- Upper epidermis Hypodermis Mesophyll Vascular tissue Lower epidermis Anatomy of leaf

5. Epidermis is single layer covered with cuticle. Hypodermis is single layered And sclerenchymatous hypodermis. It provides mechanical strength, protection,act as heat absorbing. Mesophyll Is differentiated into palisade parenchyma and spongy parenchyma . Palisade parenchyma present below upper epidermis it consists vertical alongated columnar cells ,l perform photosynthesis. Spongy parenchyma present on lower surface. They have intercellular spaces , contain chlorophyll perform photosynthesis

6. Vascular bundles are located in the centre portion of the midrib. Vascular bundles are surrounded by parenchymatous and multilayered bundle sheath. Vascular bundles similar to that of the tip of rachis. Vascular bundles are conjoint, collateral, open. Xylem composed of a large triangular-shaped centripetal xylem and two patches of laterally placed small centrifugal xylem. Phloem present on the abaxial side of the left. An inactive Cambium is present between the xylem and phloem. Lateral veins are completely absent in cycas leaf.

7. Anatomy of the stem of cycas resemble that of dicot plants The TS of stem is irregular in outline due the presence of Persistent leaf base and leaf scares. Cortex very large and composed of loosely packed parenchymatous cells. Vascular tissue consists of many vascular bundles arranged as a ringThe pith very large and parenchymatous. Many mucilage canales and leaf traces present in the cortex.Cortical and pith parenchyma contain plenty of starch grains. Leaf traces in cycas are called as girdles. Leaf traces are concentric and mesarch. Anatomy of stem

8. Parenchymatous leaf gaps are present in cycas, hence leaves are macrophyllos. Each leaf receives four supplies from two vascular bundles from the stem . Each leaf receives four traces. Leaf traces are concentric and endarch when they start and mesarch when they pass out the cortex.

9. The presence of concentrated bundle is pteridophyte character which shows the affinity between cycas and ferns. Leaf traces in cycas are called as girdles. Leaf traces are concentric and mesarch.

10. Thank you!