Unit 14: Bioresources of Assam

1. Medicinal Plants

Medicinal plants are species possessing therapeutic properties that help prevent, alleviate, or cure various human and animal diseases. Assam boasts a rich diversity of medicinal flora.

Sarpagandha

Definition: Sarpagandha (scientifically known as Rauvolfia serpentina) is a vital medicinal shrub valued for its roots.

Key Concepts: The roots contain active alkaloids, most notably reserpine.

Real-world Applications: Used extensively in indigenous and modern medicine to treat high blood pressure (hypertension) and mental disorders such as anxiety and insomnia.

Exam-oriented Notes: Always remember that the active medicinal part is the root and its primary pharmacological use is lowering blood pressure.

Neem

Definition: Neem (Azadirachta indica) is a versatile, fast-growing evergreen tree known for its bitter properties and extensive healing attributes.

Key Concepts: Every part of the tree—leaves, bark, seeds, and oil—contains bioactive compounds like azadirachtin.

Real-world Applications: Utilized as a natural antiseptic, antibacterial, antifungal agent, and in organic pest control.

Common Mistakes: Do not confuse its timber value with its primary recognition as a medicinal plant, though all parts are useful.

Tulsi

Definition: Tulsi (Ocimum sanctum), or Holy Basil, is an aromatic perennial plant revered for its medicinal and spiritual significance.

Key Concepts: Rich in essential oils and antioxidants that boost immunity.

Real-world Applications: Commonly brewed in teas and herbal remedies to treat common colds, coughs, respiratory disorders, and stress.

Cinchona

Definition: Cinchona is a genus of flowering plants whose bark is the source of important medicinal alkaloids.

Key Concepts: The bark contains quinine, a potent natural compound.

Real-world Applications: Historically and presently recognized for treating malaria and relieving muscle cramps.

Important Observation: Cinchona bark extract transformed the global treatment of vector-borne parasitic infections.

Atropa

Definition: Atropa (commonly known as Deadly Nightshade, Atropa belladonna) is a toxic perennial herbaceous plant with high pharmaceutical value.

Key Concepts: Contains powerful alkaloids such as atropine and scopolamine.

Real-world Applications: Used in modern medicine to dilate pupils during eye examinations and as an antidote for certain nerve agent poisonings.

Exam-oriented Notes: Emphasize that despite its high toxicity in raw forms, purified extracts are vital pharmaceutical drugs.

2. Timber Yielding Plants

Timber-yielding plants provide wood used for construction, furniture making, and various industrial applications due to their durability, strength, and grain quality.

Teak

Definition: Teak (Tectona grandis) is a tropical hardwood tree renowned for its weathering resistance and durability.

Key Concepts: Contains natural oils that make it highly resistant to termite attacks, moisture, and rotting.

Real-world Applications: Premium furniture, indoor and outdoor flooring, boat building, and structural construction.

Sal

Definition: Sal (Shorea robusta) is a major Indian hardwood tree species found abundantly in forest ecosystems.

Key Concepts: The wood is hard, heavy, and extremely durable, making it resistant to white ants and fungi.

Real-world Applications: Railway sleepers, heavy construction, bridge building, and door-window frames.

Sissoo

Definition: Sissoo (Dalbergia sissoo), commonly known as Indian Rosewood, is a fast-growing deciduous timber tree.

Key Concepts: Produces strong, durable timber with a fine decorative grain.

Real-world Applications: High-end cabinetry, decorative plywood, musical instruments, and carving.

Gomari

Definition: Gomari (Gmelina arborea) is a moderate to large-sized deciduous tree valued for its light yet strong timber.

Key Concepts: Easy to season, does not warp easily, and takes a good finish.

Real-world Applications: General construction, furniture, carriages, panels, and artificial limbs.

Hollong

Definition: Hollong (Dipterocarpus macrocarpus) is a majestic evergreen tree and the state tree of Assam.

Key Concepts: Yields a strong hardwood used extensively in structural works and plywood industries.

Real-world Applications: Heavy construction, railway carriages, utility poles, and commercial plywood manufacturing.

3. Sericogenic Resources

Sericogenic resources refer to silk-producing insects and the host plants that support them, forming the backbone of the traditional sericulture industry in Assam.

Muga

Definition: Muga silk is a wild silk unique to Assam, produced by the silkworm species Antheraea assamensis.

Key Concepts: Famous for its glossy golden-yellow sheen, extreme durability, and property of becoming stronger with age.

Primary Host Plants: Som (Machilus bombycina) and Soalu (Litsea monopetala).

Real-world Applications: Traditional Assamese garments such as Mekhela Chador, sarees, and luxury ethnic wear.

Exam-oriented Notes: Muga holds a Geographical Indication (GI) tag and is endemic to the Brahmaputra valley of Assam.

Eri

Definition: Eri silk is a sustainable, textile-grade silk produced by the silkworm Samia ricini.

Key Concepts: Often referred to as 'Peace Silk' because the moth emerges from the cocoon naturally before the silk is harvested, meaning no pupae are killed during processing.

Primary Host Plants: Castor (Ricinus communis) and Kesseru (Heteropanax fragrans).

Real-world Applications: Thermal wear, shawls, winter blankets, and soft fabrics due to its woolly texture and warmth.