Pachypodium rosulatum

Native to Madagascar, this succulent shrub develops a swollen water-storing base and branching, thorny stems. Yellow flowers rise on long stalks and have five spreading lobes. It grows in rocky, dry habitats, including crevices and pockets of humus. Flowering ends the lengthwise growth of a shoot, encouraging branching afterward. The species belongs to Apocynaceae. Photographed in Florida.