Swiss Chard

Russian Tortoise

Agrionemys horsfieldii

High oxalate (like spinach) binds calcium and can impair absorption with regular feeding.

Hermann's Tortoise

Testudo hermanni

High oxalate content — same calcium-binding concern as spinach.

Greek Tortoise

Testudo graeca

High oxalate — same calcium-binding concern as spinach.

Eastern Box Turtle

Terrapene carolina

[confidence: high] [source: USDA FoodData Central oxalate data; Tortoise Trust calcium and oxalate article] Very high oxalate content binds calcium and can impair absorption; feed very sparingly or avoid in favor of lower-oxalate greens.

Leopard Tortoise

Stigmochelys pardalis

[confidence: high] [source: Reptifiles leopard tortoise care; USDA FoodData Central oxalate data] Very high oxalate; can impair calcium absorption; particularly concerning given leopard tortoises' sensitivity to oxalates.

Painted Turtle

Chrysemys picta

[confidence: high] [source: USDA FoodData Central oxalate data; VCA Animal Hospitals turtle diet guide] High oxalate content; feed sparingly as part of varied leafy greens for painted turtles.

Red-eared Slider

Trachemys scripta elegans

[confidence: high] [source: USDA FoodData Central oxalate data; VCA Animal Hospitals red-eared slider diet guide] High oxalate; feed sparingly as part of varied leafy greens.

Red-footed Tortoise

Chelonoidis carbonarius

[confidence: high] [source: Reptifiles red-footed tortoise care; USDA FoodData Central oxalate data] Very high oxalate; can impair calcium absorption; feed very sparingly or avoid.

Sulcata Tortoise

Centrochelys sulcata

[confidence: high] [source: Reptifiles sulcata tortoise care; USDA FoodData Central oxalate data] Very high oxalate; particularly harmful for Sulcata tortoises sensitive to oxalates; avoid.

Yellow-bellied Slider

Trachemys scripta scripta

[confidence: high] [source: USDA FoodData Central oxalate data; VCA Animal Hospitals turtle diet guide] High oxalate; feed sparingly as part of varied leafy greens for yellow-bellied sliders.