Oshá is strictly a mountain plant, and it is most commonly found in deep, moist soils rich in organic material.

[1] Oshá has the typical appearance of members of the carrot family (Apiaceae), with parsley-like leaves and double umbels of white flowers.

When this skin is removed, the inner root tissue is fibrous and yellowish-white with an overpowering, pleasant "spicy celery" fragrance that resembles lovage (Levisticum officinale).

Most poison hemlock plants have purple blotches or shading on the lower stem if they are fairly mature, but again, this is not always the case.

Unlike its poisonous cousins, oshá does not tolerate overly moist soils (because it depends on mycorrhizal fungi) and is never found growing in standing water.

[citation needed] If the plant is growing near water in consistently moist soil, is tall (0.75–2m), has purple splotches on the main stem, and is heavily branched with small umbels of white flowers, it is probably poison hemlock and should be avoided.

In any case, due to the high toxicity of poison hemlock, if a supposed oshá plant cannot be positively identified, it must be discarded.

People who have come into contact with these plants, including crushing the leaves to perform a "smell test," should wash their hands immediately and avoid touching their eyes or mouth.

According to the ethnobotanist Shawn Sigstedt, who lived and studied with the Diné, a story is told of the brown bear's affinity for the oshá roots.