Draw the structure of boric acid shown hydrogen bonding. Which species is present in water? What is the hybridisation of boron in this species?

Orthoboric acid H3BO3, in solid state possesses a layer structure made up of $\mathrm{B}{\left(\mathrm{OH}\right)}_{3}$ units forming hexagonal rings of H-bonding as given below
Each H-atom acts as a bridge between two oxygen atoms of different ${\mathrm{BO}}_{3}^{3-}$ units.
Boric acid when dissolved in water, act as Lewis acid forming $\mathrm{B}{\left(\mathrm{OH}\right)}_{4}^{-}$
${\mathrm{H}}_{3}{\mathrm{BO}}_{3}+{\mathrm{H}}_{2}\mathrm{O}\to \mathrm{B}{\left(\mathrm{OH}\right)}_{4}^{-}+{\mathrm{H}}^{+}$
The hybridisation of boron in $\mathrm{B}{\left(\mathrm{OH}\right)}_{4}^{-}$ is sp3.