Saint-Andrew’s-cross, (Hypericum hypericoides), plant of the family Hypericaceae, native to southeastern North America and Central America, sometimes cultivated for its four-petaled yellow flowers. It reaches 75 cm (2.5 feet) and has many branches, two-angled stems, oblong to narrow leaves, and 1.5-cm- (0.6-inch-) wide, golden-yellow flowers at the stem tips. A similar but shorter species is St.-Peter’s-wort (H. stans), native to southeastern North America. It has larger flowers and leaves that clasp the stem.