$\oint$ stands for $\ldots A \ldots$ $\oplus$ stands for ...$B$... $\%$ stands for ...$C$...
Here, $A$ to $C$ refers to

• A
  $A$-bisexual plant, $B$-actinomorphic, $C$-zygomorphic
• B
  $A$-unisexual, $B$-actinomorphic, $C$-zygomorphic
• C
  $A$-unisexual, $B$-zygomorphic, $C$-actinomorphic
• D
  $A$-bisexual plant, $B$-zygomorphic, $C$-actinomorphic