Commercially useful surface fibers are obtained from which of the following?

Select the correct match for $X$ and $Y$:

Column $X$	Column $Y$
$(1)$ Hibiscus	$(P)$ Bougainvillea spectabilis
$(2)$ Catharanthus roseus	$(Q)$ Lemon
$(3)$ Bougainvillea	$(R)$ Hibiscus rosa-sinensis
$(4)$ Citrus limon	$(S)$ Periwinkle

Colchicine:
$I.$ is obtained from $Colchicum \text{ } autumnale$
$II.$ is a cytokinesis inhibitor
$III.$ induces polyploidy
$IV.$ is obtained from $Fabaceae$ family
$V.$ Floral formula: $\oplus \text{ } \text{O} \text{ } P_{3+3} A_{3+3} G_{(3)}$
Which are the correct statements?

Statement $X$: $Hibiscus$ $rosa-sinensis$ was placed in $Thalamiflorae$ by $Bentham$ and $Hooker$.
Statement $Y$: It possesses a cup-shaped thalamus and its petals are fused.

Which of the following is a submerged hydrophyte?

Choose the correct sentence.