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Osmadenia tenella

Common name: False Rosinweed

Osmadenia tenella (also called False Rosinweed or simply Osmadenia) is a small white herb with sometimes pink dots on its petals. It is native to California, but Calflora has no recorded observations further north than Los Angeles County, so they’re really limited to Southern California (and probably Baja California).

In San Diego we find it flowering, depending on the exact location, from May through July — a time when a lot of the most vivid spring green has already disappeared, which makes the appearance of the Osmadenia all the more lovely.

While the entire plant can grow relatively tall (1-2 feet, I’d say), the flowers itself are really tiny, with a diameter of just 10mm. What they lack in size, the make up in beauty and delicate details, as you can see in the macro photos below, and in years with good winter rains, also in numbers: where it is established, the plant will appear in carpets in the openings between shrubs in the sage scrub then.



Osmadenia comes from Greek osma, odor, and aden, gland, so it means “herb with strong scented glands”. The species epithet tenella is the feminine form of the Latin tenellus, meaning tender or delicate.

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