BARK Flashcards
consists of external tissues lying outside the cambium, in stem or root of dicotyledonous plants.
The bark
Methods of collection of barks
Felling method
Uprooting method
Coppicing method
The fully grown tree is cut down near the ground level by an axe.
Felling method
In this method, the stem of definite age and diameter are cut down, the root is dug up and bark is collected from roots, stems and branches.
Uprooting method
The plant is allowed to grow up to certain age and diameter.
Coppicing method
depends upon the mode of cuts made and the extent and shrinkage occurred during drying.
The shape of the bark
Morphology of bark (SHAPE)
Flat
Curved
Recurved
Chanelled
Quill
Double quill
Compound quill
Morphology of bark (outer surface)
Smooth
Lenticels
Cracks and fissures
Longitudinal wrinkles
Furrows
Exfoliation
Rhytidoma
Corky warts
Epiphytes
Morphology of bark (inner surface)
Striations
Corrugations
The appearance of exposed surface of
trans-versely broken bark
Fracture
When the large piece of the bark is collected from old trunk and dried under pressure, e.g. Quillaia and Aarjuna barks.
Flat
both the sides of the bark are curved inside, e.g. Wild cherry, Cassia and Cascara barks.
Curved
Both sides of bark are curved outside, e.g. Kurchi bark.
recurved
When the sides of bark are curved towards innerside to form channel, e.g. Cascara, Cassia and Cinnamon barks.
Chanelled
If one edge of bark covers the other edge, e.g. Ceylon, Cinnamon and Cascara barks
Quill
both the edges curve inward, e.g. Cinnamon and Cassia barks.
Double quill
When the quills of smaller diameter are packed into bigger quills
Compound quill, e.g. Cinnamon bark
When development of cork is even, e.g. Arjuna bark.
smooth
They are transversely elongated hole formed on outer surface because of lateral pressure, e.g. Wild Cherry and Cascara barks.
Lenticels
They are formed due to increase in diameter, e.g. Cinchona bark
Cracks and fissures
They are formed because of shrinkage of soft tissues, e.g. Cascara bark.
Longitudinal wrinkles
If troughs between wrinkles are wide, e.g. Cinchona calisaya bark.
Furrows
Sometimes the cork of bark flakes off exposing cortex, e.g. in Wild cherry bark.
Exfoliation
It is composite dead tissue consisting of alternate layers of cork, cortex and/or phloem, e.g. Quillaia and Tomentosa barks.
Rhytidoma
They are the small circular patches, found sometimes in old barks, e.g. in Cinchona succirubra and Ashoka barks.
Corky warts
such as moss, lichen and liverwarts are
sometimes seen in bark, e.g. Cascara bark.
Epiphytes
When parallel longitudinal ridges are formed during drying, it may be fine or coarse, e.g. Cascara bark.
Striations
They are the parallel transverse wrinkles formed due to longitudinal shrinkage, e.g. Cascara bark.
Corrugations
