Page 4 - LN-ANATOMY OF FLOWERING PLANT

The parenchyma can be further classified as
* Chlorenchyma specialised for photosynthesis.
* Aerenchyma forms a connected air system throughout the entire plant.
* Storage parenchyma store sugars, protein granules, oil drops, etc.
* Xylem parenchyma helps in the conduction of water.
* Phloem parenchyma help in the translocation of food.
* Stellate parenchyma star-shaped parenchymatous tissue with large air spaces.
Different functions performed by parenchyma are
(a) These helps in storage of food, water and air,
(b) The vital activities like photosynthesis, respiration and conduction are carried out
by parenchyma.
(c) It helps in wound healing, grafting, etc., and also provides buoyancy in aquatic
plants.
(d) Parenchyma cells associated with xylem and phloem help in conduction of water,
and food materials.
(e) These cells can dedifferentiate, acquire the power of division to form secondary
meristem which produce secondary tissues.
ii. Collenchyma
Collenchyma (Gr. Colla – glue; enchyma – an infusion) is a simple, living mechanical
tissue. Its cells composed of more or less elongated cells with thick, primary non-
lignified walls. Intercellular spaces are found to be absent.
The characteristic features ofcollenchymatous tissues are listed below
(a) It is present only in the aerial parts of the plant body.
(b) It is found either as a homogeneous layer or in patches.
(c) Collenchyma consists of cells’ which are much thickened at the corners due to a
deposition of cellulose, hemicellulose and pectin. id) The cells may be oval, spherical
or polygonal and often contain chloroplasts.
(e) These cells assimilate food, when they contain chloroplasts.