STEM:EPHEDRA - EXPERIMENT

STEM:EPHEDRA

AIM:

To study the histological characters of  Ephedra stem.

Requirements:

Chemicals:

Chloralhydrate solution, Phloroglucinol solution, conc. HCl, glycerine.

Glasswares:

Micro slides, cover slips, compound microscope, watch glass.

Crude drugs:

Ephedra stem

Description:

T.S of the Ephedra shows following important tissues from the periphery to the center.

Epidermis:

It is outer most layer and is one celled thick. It is covered with thick cuticle. Epidermis is made up of quadrangular cells of parenchyma. Stomata is sunken in nature.  

Cortex:

2 to 3 layers of cortical parenchyma appearing like loosely arranged palisade cells containing chloroplast.

Group of unlignified fibres appearing like a bunch of grapes occur below the ridges where no palisade like cells are found.

Scattered lignified fibres either isolated or in groups of 2 to 4 occur in the inner layers of cortical parenchyma.

Calcium oxalate crystals are abundent.

Pericycle: Pericycle is found above the phloem fibre, it is made up of pericyclic fibres( sclerenchymatous cells) these fibres are lignified.

Vascular bundles:

These are around 10, collateral, open and arranged in the ring.

Cambium is present between the phloem and xylem.

Phloem is towards outer side, and xylem is towards the center.

Phloem: It is made up of phloem parenchyma, seive tubes and companian cells

Xylem: Xylem is made up of vessels, tracheids, xylem parenchyma and fibres.

Group of lignified pericyclic fibres. Well developed xylem consist of vessels, tracheids, fibrotracheids and parenchyma.

Pith:

Pith is the center portion of the stem.

It is large and made up of thin walled lignified, big polygonal parenchyma with intercellular spaces. Some cells of pith contain brownish matter. Lignified fibres are also present.