Latin Name:Lewisia spp., esp. L. cotyledon and L. rediviva
Family Name: Portulacaceae
The roots of the Lewisia (especially L. rediviva) have traditionally been boiled and eaten by humans, and it is known that cattle graze on it, but we feel that it is probably wise to refrain from feeding this plant in any quantity to your tortoise, as there are some reports that it can be high in saponins (which are not toxic but can have anti-nutritional effects).
Also many plants in this family are high in oxalic acid, and although we have not seen reports of oxalic acid content in Lewisia, we think it best to err on the side of caution and feed sparingly.