Plant reproductive morphology is asexual, producing only spores. Similarly, flowers produced by the sporophyte may be described as "unisexual" or "bisexual", meaning that they give rise to either one sex of gametophyte or both sexes of gametophyte. The flower is the characteristic structure concerned with sexual reproduction in flowering plants (angiosperms). Flowers vary enormously in their construction (morphology). A "complete" flower, like that of "Ranunculus glaberrimus" shown in the figure, has a calyx of outer sepals and a corolla of inner petals. The sepals and petals together form the perianth. Next inwards there are numerous stamens, which produce pollen grains, each containing a
Cliffortia have arisen at four independent occasions. Trimerous flowers have three sepals of variable size, and in male flowers six to many stamens. Tetramerous flowers have four sepals of 5 mm long at most and either four or eight stamens. In female flowers the sepals are united at their base to form a calyx tube, and have one or two styles, that are finely divided like an ostridge feather. One or two achenes may develop in each flower, within the inflating calyx. The first who mentioned species that are currently assigned to "Cliffortia" was Leonard Plukenet in 1696. Names published before