Glossary of plant morphology flowers, a tube or cup-like hypanthium (floral tube) is formed above or around the ovary and bears the sepals, petals, and stamens. There may also be a nectary producing nectar. Nectaries may develop on or in the perianth, receptacle, androecium (stamens), or gynoecium. In some flowers nectar may be produced on nectariferous disks. Disks may arise from the receptable and are doughnut- or disk-shaped. They may also surround the stamens (extrastaminal), be at the stamen bases (staminal), or be inside the stamina (intrastaminal). Finally, the actual reproductive parts form the innermost layers of the flower. These leaf primordia become specialised
Polygonum ramosissimum calyx. The calyx is around long and 5-parted with the outer three sepals longer than the inner sepals. The seeds are produced in fruits called achenes, which are egg-shaped, dark brown and around long. The achenes also have a smooth shiny surface. The late season achenes are larger, from 4 to 15 mm long. There are a number of forms and two subspecies, that vary in flower and foliage coloration. "Polygonum ramosissimum" has great morphological variability, which is notable on the same plant, between flowers and fruits produced early in the blooming season verses those produced late in the season,