Step 1: Understanding the Question:
We need to pair four crude drugs, snake root, artemisia, bitter almond and myrrh, with the plant family each one belongs to: Compositae, Rosaceae, Apocynaceae and Burseraceae.
Step 2: Key Formula or Approach:
Each of these drugs is a classic pharmacognosy example tied to one specific family through its source plant, so recalling the source plant for each drug fixes the match directly.
Step 3: Detailed Explanation:
Snake root is obtained from Rauwolfia serpentina, a source of indole alkaloids such as reserpine, and Rauwolfia belongs to the family Apocynaceae.
Artemisia species, such as Artemisia annua, are the source of sesquiterpene lactones like artemisinin, and this genus is placed in the family Compositae (Asteraceae).
Bitter almond is the seed of Prunus amygdalus var. amara, and Prunus is a member of the family Rosaceae, the same family that gives us drugs like wild cherry bark.
Myrrh is an oleo-gum-resin obtained from Commiphora species, and Commiphora belongs to the family Burseraceae, along with related resins such as guggul.
Matching each drug to its family gives snake root with Apocynaceae (R), artemisia with Compositae (P), bitter almond with Rosaceae (Q), and myrrh with Burseraceae (S).
Step 4: Final Answer:
The correct match is 1-[R], 2-[P], 3-[Q], 4-[S].