Euphorbia mammilaris: Indian Corn Cob is a succulent columnar, cactus-like plant studded with occasionalÂ spikes that resemble toothpicks. They are drought tolerant and need great drainage. Water once a week in the summer and up to once a month in the winter, allowing the soil to fully dry out between waterings. Can reach 1 foot tall and sprout new branches from its base. Provide with sun outside and bright light inside. Low water.