English: Nylon hedgehog cactus; Green pitaya; Small-flowered hedgehog cactus.
Region: central and south-central United States, northern Mexico.
Habitat: various types, desert scrub, woodlands, dry grasslands, short-grass prairie.
Botany: small spherical or cylindrical stem, 3 to 30 centimeters, 9 centimeters wide; unbranched or several branches, ridged, lined with many areoles with spines; spines red, yellow, white, purplish, or bicolored, sometimes with darker tips; flower ± 3 centimeters long, tepals yellowish, brownish, greenish, occasionally red, with darker reddish midstripes, thin at the tips.