Streptanthus cordatus stem. Flowers occur at intervals along the upper stem. Each has a calyx of sepals roughly a centimeter long which begin greenish yellow and mature purple. Four purple petals emerge from the tip of each calyx. The fruit is a thin, narrow silique which may reach 14 centimeters in length or longer. Streptanthus cordatus Streptanthus cordatus is a species of flowering plant in the mustard family known by the common name heartleaf twistflower. It is native to the western United States, where it can be found in many types of sagebrush, woodland, and forest habitat. It is a perennial herb
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