taproot Fibrous root Roots are natural selection's design solution to the problems of obtaining resources from a heterogeneous(异质,多相), porous(多孔的), emi-compressible(半刚性的) medium containing solid, liquid and gaseous phases. (Robinson 1991)“Roots are natural selection’s design solution to the problems of obtaining resources from a heterogeneous（异质，多相）, porous（多孔的）, semi-compressible（半刚性的） medium containing solid, liquid and gaseous phases.” (Robinson 1991) Fibrous root taproot