RH Botany, Plant Identification & Materia Medica 3 — Questions and Answers
Question 1: Which taxonomic rank falls directly between family and species in the Linnaean classification system?
- Order
- Class
- Genus (Correct answer)
- Division
Correct answer: Genus
The hierarchy from broad to specific is: Kingdom → Phylum → Class → Order → Family → Genus → Species.
Question 2: Glycyrrhiza glabra root is contraindicated in patients with hypertension primarily due to its content of:
- Flavonoids that inhibit ACE
- Glycyrrhizin, which causes sodium retention and potassium loss (Correct answer)
- Saponins that increase blood viscosity
- Tannins that constrict blood vessels
Correct answer: Glycyrrhizin, which causes sodium retention and potassium loss
Glycyrrhizin inhibits 11β-hydroxysteroid dehydrogenase, causing a pseudoaldosterone effect with sodium retention, potassium loss, and elevated blood pressure.
Question 3: The term 'diaphoretic' describes herbs that:
- Promote bile production
- Induce perspiration to support fever management (Correct answer)
- Increase urine output
- Stimulate bowel movement
Correct answer: Induce perspiration to support fever management
Diaphoretics promote sweating, which can help reduce fever and support elimination through the skin; elderflower and yarrow are classic examples.
Question 4: Which structural feature of Echinacea purpurea distinguishes it from E. angustifolia in field identification?
- Absence of ray florets
- Broader, ovate leaves vs. narrow lanceolate leaves (Correct answer)
- White rather than purple ray florets
- Hollow rather than pithy stem
Correct answer: Broader, ovate leaves vs. narrow lanceolate leaves
E. purpurea has broad ovate leaves, while E. angustifolia has narrow lanceolate leaves; both have purple ray florets but differ significantly in leaf morphology.
Question 5: Silymarin, the primary active constituent of Silybum marianum, is classified as a:
- Monoterpene
- Flavonolignan complex (Correct answer)
- Iridoid glycoside
- Phenolic acid
Correct answer: Flavonolignan complex
Silymarin is a mixture of flavonolignans (silybin, silydianin, silychristin) found in milk thistle seeds, known for hepatoprotective activity.
Question 6: A plant described as 'rhizomatous' propagates vegetatively via:
- Horizontal underground stems that produce new shoots (Correct answer)
- Aerial stolons that root at nodes
- Fleshy taproots that divide naturally
- Wind-dispersed seeds
Correct answer: Horizontal underground stems that produce new shoots
Rhizomes are horizontal underground stems (not true roots) that extend laterally and produce new shoots, as seen in ginger, goldenseal, and Solomon's seal.
Question 7: Which of the following plants belongs to the Solanaceae family and requires caution due to alkaloid content?
- Calendula officinalis
- Lobelia inflata
- Datura stramonium (Correct answer)
- Arctium lappa
Correct answer: Datura stramonium
Datura (jimsonweed) belongs to Solanaceae and contains tropane alkaloids (scopolamine, atropine, hyoscyamine) that are toxic and potentially fatal in misuse.
RH Botany, Plant Identification & Materia Medica 3
Which taxonomic rank falls directly between family and species in the Linnaean classification system?