Cressa is a genus of plants in the morning glory family known generally as alkaliweeds. These plants are native to the tropical and subtropical areas of the world. They are clumpy and low-growing but usually have erect stems covered white-haired, green leaves. They produce tiny white flowers about half a centimeter across. There are four species in the genus. Species include: * Cressa australis * Cressa cretica * Cressa nudicaulis * Cressa truxillensis