Molten Si was allowed to solidify isothermally at initial bulk undercoolings ΔT from 5.7 to 157 K. It was found that in addition to the 〈211〉 twin dendrites two novel dendrites were found: the 〈110〉 twin and the 〈100〉 twin free dendrite. The 〈110〉 twin dendrite has multiple twin planes, and the orientation of the twin plane is {111}. These different dendrites exist at different initial bulk undercoolings, and the dendritic transition temperatures for 〈110〉 to 〈211〉 and 〈211〉 to 〈100〉 are ΔT=22 and 68 K, respectively. The dendritic transitions for 〈110〉 to 〈211〉 and 〈211〉 to 〈100〉 are edgewise to edgewise and edgewise to continuous normal growth, respectively.