A cyme is a determinate inflorescence: the main growing tip ends in a flower, so further flowers can only come from side branches below it. The four pairs here test whether you can match each cyme sub-type to a correct plant example.
- Solitary cyme, Hibiscus: When only one flower forms at the tip and no side branches take over, that is a solitary cyme reduced to a single flower. Hibiscus commonly shows this single terminal flower pattern, so the pairing holds.
- Dichasial cyme, Ipomea: A dichasial cyme needs two lateral branches to arise together just below the terminal flower. Ipomea (morning glory) does not typically branch this way; its cymose growth follows a different, one sided pattern. Pairing it with dichasial cyme is incorrect.
- Monochasial cyme, Hamelia: A monochasial cyme produces just one lateral branch at each node, giving a zig zag or coiled look. Hamelia is a standard textbook example of this one sided branching, so this pair is correct.
- Polychasial cyme, Nerium: A polychasial cyme sends out more than two lateral branches below the terminal flower. Nerium (oleander) is the standard example used for this multi branched cyme, so the pair is correct.
Because three of the pairs describe the plant's real branching habit correctly and only Ipomea is mismatched with the dichasial pattern, that is the incorrect pair.
Let's summarize:
- Solitary cyme: one terminal flower, no branching (Hibiscus).
- Monochasial: one lateral branch per node (Hamelia).
- Polychasial: more than two lateral branches (Nerium).
- Dichasial needs exactly two lateral branches, a pattern Ipomea does not show.
So the incorrect pair is dichasial cyme with Ipomea.