query: parent_taxon anulocaulis
supports: Nyctaginaceae, the four o'clock family, is a family of around 33 genera and 290 species of flowering plants, widely distributed in tropical and subtropical regions, with a few representatives in temperate regions. The family has a unique fruit type, called an "anthocarp", and many genera have extremely large (>100 µm) pollen grains. Boerhavia is a genus of over 100 species in the four o'clock flower family, Nyctaginaceae. Some species are annuals and others perennials. In habit they generally are herbaceous. Anulocaulis is a small genus of flowering plants known generally as ringstems . These five species are sometimes treated as members of genus Boerhavia . Ringstems are thickly - rooted perennial wildflowers with glutinous brown bands at their stem internodes , the trait which gives them their common and Latin names . They bear tubular flowers at the tops of their stems . Ringstems are native to North America .
candidates: boerhavia nyctaginaceae
answer: nyctaginaceae