Gog:Oenothera tetragona
WikiPedia:Oenothera
O. biennis, also know as the common evening primrose and Evening Star, is a biennial plant growing to 1.2Metre, with easy germination. Its hermaphrodite pale yellow flowers (for most of the summer - from June to September - reaching a height of 3 to 4 feet) open in the evening, hence the name “evening primrose”, are pollinated by Lepidoptera (Moths and Butterflies) and bees.
It originated in Mexico and Central America some 70,000 years ago. During the Pleistocene era a succession of ice ages swept down across North America, with intervening warm periods. This was repeated for four ice ages, with four separate waves of colonisation, each hybridising with the remnants of the previous waves. This generated a present day population which is enormously rich in genetic diversity, spread right across the North American continent. It’s very popular in gardens, and is now also naturalised in parts of Europe and Asia. The first plants to arrive in Europe, reached Padua from Virginia in 1614 and were described by the English botanist John Goodyer in 1621. The plant is now naturalised in several parts of Great Britain.
Evening primrose must be planted in any ordinary, dry, well drained garden soil (preferly sandy loam) in an open site that is sunny to partly shady. It is drought resistant.
For propagation, sow seeds in situ from late spring to early summer. The plant will grow successfully in fertile soils (such as gardens) if competing species are kept at bay. In the wild, evening primrose acts as a primary coloniser, springing up wherever a patch of bare, undisturbed ground may be found. This means that it tends to be found in poorer environments such as dunes, roadsides, railway embankments and wasteland. It often occurs as a casual, eventually being out-competed by other species. It grows as far north as 65° N in Finland.
Young roots can be eaten like a vegetable (with a peppery flavour), or the shoots can be eaten as a salad. The whole plant was used to prepare an infusion with astringent and sedative properties. It was considered to be effective in healing asthmatic coughs, gastro-intestinal disorders, whooping cough and as a sedative pain-killer. Poultices containing O. biennis were used to ease bruises and speed wound healing. One of the common names for Oenothera, “Kings cureall”, reflects the wide range of healing powers ascribed to this plant, although it should be noted that its efficacy for these purposes has not been demonstrated in clinical trials.
The seeds ripen from August to October. The mature seeds of the evening primrose contains approximately 7-10% gamma-linolenic acid (gamma-linolenic acid), a rare essential fatty acid. The Onagra biennis seed oil is used to reduce the pains in the premenstrual stress syndrome.
http://www.em.ca/garden/per_oenothera_tetragona1.html
If you want to cheer up a dreary corner of your garden, plant Sundrops. When in bloom,
a patch of several plants presents almost a blinding splash of yellow.
Begins blooming in late June. The flowers are 1.5 inches or so in diameter, and close up in the evenings. Flowers emerge from attractive red-coloured flower buds.
Needs to be in full sun, will get floppy and require staking in partial shade. Drought tolerant in our expereience, easy to grow.
Problems - plants can require staking if too close together, even in full sun. Spreads, but not so much I’d call it invasive - in good soil, in a couple of years you’ll have many plants to move to another location or give away. Deadheading can take a while, there’s a lot of blooms. Every couple of years you need to thin out a some plants, otherwise forms a very thick patch.
I have seen O. fruiticosa is listed as a synonym. Other reference books list O. fruiticosa and O. tetragona as separate species.
Hardy zone 3.
Height is 15 inches to 20 inches. As mentioned above, in good soil will spread to form a patch 3 feet wide.