Oxalis: The Purple Shamrock Plant That Folds Its Leaves at Night

The plant your wife calls "OXYDELIS" is almost certainly an Oxalis species, commonly known as purple shamrock or false shamrock. Oxalis triangularis (syn. Oxalis regnellii) is a popular houseplant with deep purple, heart-shaped leaflets that fold down at night (nyctinasty) and reopen in daylight.

It produces delicate white or pale pink flowers. While charming indoors, Oxalis can become a greenhouse weed because its seed pods explode when ripe, shooting seeds up to 20–30 feet. As a houseplant, it's easily managed—just remove spent flowers to prevent seeding.

Provide bright, indirect light, well-draining soil, and allow the top inch of soil to dry between waterings. It goes dormant periodically; reduce watering until new growth appears. Fertilize lightly during active growth.