common evening-primrose
This native biennial is found in open disturbed habitats such as fields, roadsides and waste places across North America and are only absent from deserts. After introduction to Europe in the 1600's as an ornamental plant, it is now widely naturalized in temperate and sub-tropical regions worldwide.
At Salter Grove, flowering begins as early as June and continues until early October. The flowers open overnight and are probably pollinated by night-flying insects. Individuals with conspicuous yellow flowers can be found growing along the causeway or at the edge of lawns. By October, newly released seeds have grown into rosettes of leaves that start storing reserves for a spurt of growth the following spring. Stalks with dried fruit capsules that persist through the winter indicate where plants were growing the previous season.
All parts of the common evening primrose can be eaten before flowering occurs. The stout taproot can be boiled like potatoes, the young leaves used in salads or as greens. Both the young flowering stem as well as the flowers are also edible. The seeds have a high oil content and can be roasted and used like sesame seeds. The presence of several essential amino acids promotes its use as a nutritional supplement. It is surprising that despite its ability to grow in habitats with low levels of water and its potential as an oil crop, there has not been a greater push to develop it as an agricultural species.