Oenothera

The evening primrose (Oenothera) are a genus of the evening primrose family (Onagraceae). It contains about 120 to 200 species. Originally evening primrose species in North America were widespread. Already in the 17th Century they were introduced as ornamental plants to Europe. They are as wild and neophytes constant feature of the Central European flora

They are originally from the temperate regions of North, Central and South America. The center of biodiversity is the southwestern North America. Many species have become naturalized in many other countries.

Vegetative characteristics
Evening primrose species are one-, two-year and perennial herbaceous plants. Some species produce rhizomes as Überdauerungsorgane. Some species form tap roots. The leaves are in a rosette or alternate and spirally distributed around the stem. The leaf margin is smooth to lobed. Stipules absent.

Generative characteristics
The flowers are individually, together in the leaf axils or in differences in the structure inflorescences. The hermaphroditic, but somewhat flowers are m tall with a double perianth. The four green to yellow petals often have a red or purple-colored drawing and are grown Röhrig. The four free petals are white, yellow or pink to purple color. There are two circles, each with four stamens present. The four carpels are fused to an inferior, vierfächerigen ovary containing many ovules. The stigma is four-lobed.

Pedunculated or sessile are formed capsule fruit with many seeds.


Source: http://de.wikipedia.org/wiki/Nachtkerzen
See Also: sending flowers, online florist