ide . ▁ ▁The ▁bor anes ▁( bor on ▁hydro gen ▁comp ounds ) ▁and ▁similar ▁g ase ous ▁comp ounds ▁are ▁quite ▁poison ous . ▁As ▁usual , ▁it ▁is ▁not ▁an ▁element ▁that ▁is ▁intr ins ically ▁poison ous , ▁but ▁their ▁to x icity ▁depends ▁on ▁structure . ▁The ▁bor anes ▁are ▁also ▁highly ▁fl amm able ▁and ▁require ▁special ▁care ▁when ▁handling . ▁S od ium ▁bor oh yd ride ▁presents ▁a ▁fire ▁ha z ard ▁ow ing ▁to ▁its ▁reducing ▁nature ▁and ▁the ▁liber ation ▁of ▁hydro gen ▁on ▁contact ▁with ▁acid . ▁Bor on ▁hal ides ▁are ▁cor ros ive . ▁ ▁Bor on ▁is ▁necessary ▁for ▁plant ▁growth , ▁but ▁an ▁excess ▁of ▁bor on ▁is ▁to xic ▁to ▁plants , ▁and ▁occurs ▁particularly ▁in ▁acid ic ▁soil . ▁It ▁presents ▁as ▁a ▁yellow ing ▁from ▁the ▁tip ▁in wards ▁of ▁the ▁oldest ▁leaves ▁and ▁black ▁sp ots ▁in ▁bar ley ▁leaves , ▁but ▁it ▁can ▁be ▁confused ▁with ▁other ▁str esses ▁such ▁as ▁mag nes ium ▁def ic iency ▁in ▁other ▁plants . ▁ ▁See ▁also ▁▁ ▁All otrop es ▁of ▁bor on ▁ ▁Bor on ▁def ic iency ▁ ▁Bor on ▁ox ide ▁ ▁Bor on ▁nit ride ▁ ▁Bor on ▁neut ron ▁capture ▁ther apy ▁ ▁Bor onic ▁acid ▁ ▁H ydro bor ation - ox id ation ▁reaction ▁ ▁Su zu ki ▁coupling ▁ ▁References ▁ ▁External ▁links ▁ ▁Bor on ▁at ▁The ▁Period ic ▁Table ▁of ▁Videos ▁( Univers ity ▁of