Dilleniidae: Capparales. The Brassicaceae are herbs or rarely subshrubs comprising about 350 genera and 3,000 species. The leaves are alternate or rarely opposite and typically are simple but sometimes have deeply parted segments; stipules are lacking. The flowers are bisexual and almost always actinomorphic. The perianth consists of a calyx of 4 distinct sepals and typically a corolla of 4 distinct petals that are commonly clawed and diagonally disposed. The androecium is tetradynamous, consisting of 4 long inner stamens and 2 short outer stamens. The gynoecium consists of 2 carpels that are generally separated by a persistent false partition called a replum. The superior ovary is usually 2-loculed and bears few to many ovules on parietal placentae. At maturity, the 2 valves of the fruit typically separate, leaving the ovules attached to the persistent replum. Long, narrow fruits of this family are called siliques, short broad ones are called silicles.
Each "thumbnail" image below is linked to a larger photograph.
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Raphanus sativus, wild radish. The cross-shaped configuration of the flowers in this family resulted in its early designation as the Cruciferae. The style with its small capitate stigma can be seen just above the anthers. Long, narrow fruits of this family such as that seen in this photo are called siliques. In the photo on the right the yellow anthers of four long stamens and two short stamens can be seen. This condition of the stamens is described as tetradynamous, and is typical for the family. Also visible here is the typical narrow greenish claw at the base of each petal. | ||
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Lobularia maritima, sweet alyssum. Note the typical 4-parted perianth, the androecium of 4 long and 2 short stamens, and the capitate stigma. | ||
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Capsella bursa-pastoris, shepherds purse. In this family, short broad fruits such as these are called silicles. At maturity the two valves of siliques and silicles separate from the persistent replum or false partition. A few seed stalks or funiculi can still be seen attached to the edge of some of the persistent partitions. | ||
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Iberis umbellata, candytuft. This genus is unusual in the family in having the corolla somewhat zygomorphic, with two petals larger than the other two. |
