THELIGONALES

problematic order of dicotyledonous flowering plants containing one family (Theligonaceae, sometimes called Cynocrambaceae) and one genus (Theligonum) with three species distributed in the Canary Islands, Mediterranean region, southwestern China, and Japan. The plants are somewhat succulent (fleshy) herbs with separate male and female flowers on the same plant. Male flowers usually have 7 to 12 stamens (pollen-producing structures), but the number may vary in different specimens from 2 to 30. There are two to five broad petallike structures (perianth segments) that are rolled back (revolute) when open. The female flower has an oblique membranous perianth produced into a tube with two to four teeth, or notches, at the mouth. The ovary is composed of one carpel enclosing one ovule. At the base of the ovary arises a narrow process that carries pollen-receptive surfaces at its upper end, which protrudes from the end of the perianth tube. Theligonum japonicum blooms from April to June in the woody, mountainous regions of Japan . The order bears uncertain relationship to other orders. It has been placed near the orders Haloragales, Rubiales, and Caryophyllales by various authorities at various times.