Nan sha shu teng (Coastal Morning Glory)

Ipomoea littoralis, the coastal morning glory, is a trailing or climbing herbaceous vine in the family Convolvulaceae native to tropical coastal habitats of the Indo-Pacific region, including Taiwan, Tonga, and other Pacific island groups. The species grows on sandy beaches, coastal foredunes, and rocky coastal margins exposed to salt spray and tropical sun, where it often forms extensive mats stabilizing loose substrate with its sprawling stems and deeply penetrating roots. Like other beach-dwelling Ipomoea species, it is adapted to intense sun, salt tolerance, and intermittent drought, producing large, waxy, dark green leaves that resist desiccation and salt accumulation. The funnel-shaped flowers, typical of the morning glory family, are pink to lavender in color and are pollinated by bees, butterflies, and other insects. Seeds are enclosed in hard, water-resistant capsules adapted for dispersal by ocean currents across island chains. The species is assessed as Least Concern by the IUCN. Beach morning glories play an important stabilizing role in coastal dune ecosystems across the Pacific, binding loose sand with their runners and root systems and contributing to the early colonization of bare beach sand that eventually allows succession to more complex coastal vegetation.