Veratrum tenuipetalum is sometimes classed as a separate species, or as a variety (var californicum) of
veratrum californicum, the main difference being the somewhat smaller flowers; tepals of veratrum tenuipetalum are about a third of an inch in length, while those of the other variety are nearer half an inch. Most aspects are similar; the tall, thick stems, the large, upwards-pointing green leaves with prominent, closely spaced parallel veins, and the elongated, branched inflorescence which contains hundreds of greenish-white flowers. These extend over the upper two thirds of the stem. The plant often forms extensive colonies in moist, medium elevation areas. All parts are very poisonous.