Someone said there was no taproot on sequoia.
The sequoias grow in the crevices and fissures of the massive granite batholiths that form the main structure of the Sierra.
Their root systems rarely go more than 10’ deep.
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From what I have read about them it seems that their tap root is not as important as the fact that their roots intertwine with other sequoia's roots so the underground webbing they produce is what makes them strong.