Oenothera villosa, the hairy evening primrose, is a species of flowering plant in the family Onagraceae. It is native to nearly all of the United States (except Hawaii, Alaska, Louisiana, Florida, and South Carolina), and to all Canadian provinces and the Northwest Territories. It has been introduced to cool and cold-temperate regions worldwide. An erect biennial reaching , it is typically found in open areas and disturbed situations.
Description This plant is a taproot dicotyledon (two stem leaves) biennial that has a red stem and is strigillose. This term means hairy. In this Scenario, the plant is covered in trichome hairs. The hairs are considered erect. This means that they stick straight out from the stem, not in a curled manner. The leaves are usually green in color and can have fully denticulate margins or part entire (smooth edges), part denticulate margins. in rarer scenarios the leaves can have moderate dentate margins. This all means that the leaves usually have small teeth on their edges, or have parts of their leaves of small-toothed edges. Also the rare moderate dentate margins means that sometimes a plant can be found with somewhat larger teeth on its leaf borders.
The flowers inflorescent head, or the whole flower part of the plant is in the open position. The shoot growing structure called the apex is of the obtuse type. The plant has fruit capsules that do not measure any longer than the plants shoot internodes. This means that the fruit capsules are not longer than the spacings between the plants leaf nodes. The plants campanuate (bell shaped) yellow flowers have red stripes on the outer part of the flowers, so if someone views the flowers from the sides, not staring into the flowers, they appear as yellow, and painted with red stripes. The inside of the flowers are all yellow. The flowers are arranged into a terminal spike. This means that the flowers grow from the crown, which is the middle of the plant. These flowers bloom in the summer months in the United States which is from June through September. The plant has lanceolate leaves meaning sword shaped and have sinuate lobes which means the leaf lobes have a bending wavy pattern on their lobes. The leaves are mildly to moderately covered with hairs on their surfaces, front and back. The leaves sometimes have a coating of wax on their edges. The leaves measure 2.5 to 10 cm long or 1-4 inches. The herbaceous branches are covered in these fine hairs also. The yellow striped flowers measure 1.5- 3.5 cm in width or around 0.5 inches to 1 inch. This plant has cylindrical seed pods (capsules) that are 1.3 to 3 cm (0.5-1.3 inches) long. These pods are thick at the base. The seeds are very small being only 1.3 to 1.5 mm long. The seeds are self-pollinating. This plant can usually reach a height of around 3-5 feet ( can reach 6 or 7) according to some other sources) and can be found in waste lands, disturbed areas, and alongside roads etc. The plant can be found in almost all of the U.S states except a couple extreme cold and hot/humid states. A thing to state is that some of my sources come from a species called Oenothera biennis which is in the same family and order, this is a subspecies of this plant with a few differences such as the hair (trichomes) on the stems, but most of the height and flower characteristics are very similar.
Taxonomy Oenothera villosa was given its scientific name by Carl Peter Thunberg in 1794. It is classified in the genus Oenothera as part of the Onagraceae family. It has two accepted subspecies:
Oenothera villosa subsp. strigosa – western and central North America, and introduced to central Europe Oenothera villosa subsp. villosa – central and eastern North America, and introduced worldwide
Oenothera villosa has synonyms of its two subspecies including 24 species.
Table of Synonyms Name Year Rank Synonym of: Notes Oenothera albinervis 1936 species subsp. villosa = het. Oenothera baurii 1924 species subsp. villosa = het. Oenothera biennis subsp. baurii 1950 subspecies subsp. villosa = het. Oenothera biennis var. canescens 1840 variety subsp. villosa = het. Oenothera biennis var. strigosa 1992 variety subsp. strigosa ≡ hom. Oenothera canovertex 1968 species subsp. villosa = het. Oenothera canovirens 1911 species subsp. villosa = het. Oenothera cheradophila 1907 species subsp. strigosa = het. Oenothera cockerellii 1913 species subsp. villosa = het. Oenothera communis proles erosa 1909 proles subsp. villosa = het. Oenothera depressa 1891 species subsp. villosa = het. Oenothera depressa f. angustifolia 1965 form subsp. villosa = het. Oenothera depressa f. latibracteata 1965 form subsp. villosa = het. Oenothera erosa 1828 species subsp. villosa = het. Oenothera hookeri var. parviflora 1915 variety subsp. villosa = het. Oenothera hungarica 1903 species subsp. villosa = het. Oenothera muricata var. canescens 1908 variety subsp. villosa = het. Oenothera muricata f. hungarica 1924 form subsp. villosa = het. Oenothera parviflora var. canescens 1923 variety subsp. villosa = het. Oenothera prasina 1914 species subsp. strigosa = het., nom. nud. Oenothera procera 1913 species subsp. strigosa = het. Oenothera renneri 1956 species subsp. villosa = het. Oenothera renneri f. mollis 1965 form subsp. villosa = het. Oenothera rydbergii 1921 species subsp. strigosa ≡ hom., nom. superfl. Oenothera scandinavica 2007 species subsp. villosa = het. Oenothera strigosa 1902 species subsp. strigosa ≡ hom. Oenothera strigosa var. albinervis 1957 variety subsp. villosa = het. Oenothera strigosa subsp. canovirens 1965 subspecies subsp. villosa = het. Oenothera strigosa subsp. cheradophila 1965 subspecies subsp. strigosa = het. Oenothera strigosa var. cheradophila 1957 variety subsp. strigosa = het. Oenothera strigosa var. cockerellii 1957 variety subsp. villosa = het. Oenothera strigosa var. depressa 1958 variety subsp. villosa = het. Oenothera strigosa subsp. hungarica 1961 subspecies subsp. villosa = het. Oenothera strigosa var. procera 1957 variety subsp. strigosa = het. Oenothera strigosa var. subulifera 1957 variety subsp. strigosa = het. Oenothera subulifera 1913 species subsp. strigosa = het. Oenothera velutinifolia 1968 species subsp. villosa = het. Oenothera villosa subsp. cheradophila 1976 subspecies subsp. strigosa = het. Oenothera villosa var. strigosa 1988 variety subsp. strigosa ≡ hom. Onagra biennis var. strigosa 1901 variety subsp. strigosa ≡ hom. Onagra cockerellii 1913 species subsp. villosa = het. Onagra depressa 1896 species subsp. villosa = het. Onagra erosa 1835 species subsp. villosa = het. Onagra hungarica 1902 species subsp. villosa = het. Onagra lehmanniana 1835 species subsp. villosa = het. Onagra strigosa 1900 species subsp. strigosa ≡ hom. Onagra strigosa var. subulata 1900 variety subsp. strigosa = het. Usoricum strigosum 1916 species subsp. strigosa ≡ hom. Notes: ≡ homotypic synonym; = heterotypic synonym
Uses This plant is not as common for use as some other garden or culinary plants, but it has some notable ones. A few people have planted Oenothera Villosa in gardens. This plant can be used to attract butterflies (lepidopterans) and other pollinating insects/birds. The plant has a chemical compound omega fatty-acid called Gamma Linolenic Acid (GLA) that is found in the oil called Evening Primrose Oil (EPO). This oil from a few of the closely related primrose plants including the hairy evening primrose is thought to be an ingredient that is active in some therapeutic medicine. This oil is found in the seeds of this primrose plant. The oil is being used to treat some conditions/disorders that can be targeted by using these helpful omega fatty acids found in the oil. However, the accuracy and efficacy of this oil actually relieving and treating some of these conditions is still being debated among medical people as of 2007.
Some treatment uses of EPO are in Assistive Reproductive health Technologies (ART) and medicine. This oil is being used to treat certain reproductive diseases/conditions such as female breast inflammation, Euteral diabetes, other inflammation, and menopause/menstrual disorders. Some women take this oil with the medicine before birth to help with reproductive qualities, and some have not experienced any harmful effects from its use.
This oil is prescribed for these illnesses due to its potential benefits in this field, so this is not 100 percent proven to help with these conditions.
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