Winter Quarter Week 8 Plant Family: Onagraceae

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Oenothera cespitosa

The Onagraceae, the evening primrose family, has the following characteristics:

  1. Flowers: four petals and sepals, radial symmetry, bisexual.
  2. Inflorescence: clustered in spikes, racemes, or panicles, though some species may have solitary flowers.
  3. Sepals and Petals: Petals are larger and more colorful than the sepals.
  4. Stamens: twice as many stamens as petals. The stamens are arranged in two whorls, with the outer whorl having twice as many stamens as the inner whorl.
  5. Ovary: usually inferior, situated below the attachment of other floral parts.
  6. Fruit: capsule, which splits open to release numerous small seeds.
  7. Habitat: temperate and subtropical regions. Often found in moist or wet areas such as marshes, riverbanks, and along streams, but some species can also tolerate drier conditions.
  8. Importance: Some species are cultivated as ornamental plants for their attractive flowers. Some species have medicinal or culinary uses.
  9. Notable Genera: The Onagraceae family includes several notable genera such as Oenothera (evening primroses), Epilobium (willowherbs), and Fuchsia (fuchsias).
  10. Adaptations: Many Onagraceae species have adaptations for pollination by nocturnal insects, such as moths, due to their evening blooming habits. Some species also have specialized floral structures to accommodate specific pollinators.