Evening Primrose
Evening Primrose (Oenothera biennis, family: Onagraceae) is a tall sturdy plant with bright lemon-color flowers that open in the evening. Its Japanese name means the-(small)-plant-that-waits-for-the-evening, or (me)-matsu-yoi-gusa. The flower has four petals, four sepals, four divided stigma and eight stamens.
The Onagraceae family plants share distinctive characteristics in the form of pollens and the phloem. The photo shows the pollen grains of the evening primrose flower. The string like structure called viscin threads connects each pollen grain. The next photo shows the close-up of the pollen grains and the viscin threads attached to them.
Another distinctive characteristics of the Onagraceae family plants is the phloem that circles inside the xylem, or intraxylary phloem.
The raphids or the calcium oxalate crystals can be frequently found in the plants body. This is another characteristics of the family.
Butterfly Gaura
Butterfly Gaura (Gaura lindheimeri) is another Onagraceae plant. The flower has four petals, four sepals, four divided stigma and eight stamens. The pollens are triangular and the grains are entangled in viscin threads.
