I am trying to figure out what variety of Evening Primrose I have all over my garden. (It spreads quickly.) I think it might just be plain old common evening primrose:

From Wikipedia:

It is a biennial flowering plant growing to 30–150 cm tall. The leaves are lanceolate, 5–20 cm long and 1–2.5 cm broad, produced in a tight rosette in the first year, and spirally on the stem in the second year. The flowers are pale yellow, 2.5–5 cm diameter, with four petals; they are hermaphrodite, and produced on a tall spike from late spring to late summer. They open in the evening, hence the name "evening primrose", and close by the following noon. The flower has a bright nectar guide pattern, invisible in visible light, but apparent under ultraviolet light, which assists its pollinated by Lepidoptera (moths and butterflies) and bees. The fruit is a capsule 2–4 cm long and 4–6 mm broad, containing numerous 1–2 mm long seeds, released when the capsule splits into four sections at maturity.^[2][3][4][5]

It is also known as Weedy evening-primrose, German rampion, hog weed, King's cure-all, and fever-plant.^[6]

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It's lovely but I don't have any pictures of it in flower. Here is what I think it looks like, in case anyone can help me identify it.

This is pretty cool...a video someone took of an evening primrose actually opening, in real time. Check it out:

Evening Primrose Flower Opening 1

Real time (not time-lapse) recording of an evening primrose ...
1 min 44 sec -