A variety of the Asteraceae family, Celmisia ramulosa var. tuberculata is endemic to New Zealand's South Island, where it occupies alpine screes, open rockeries, and rock fissures on siliceous substrates, generally at altitudes above 1,200 meters.
It shares with the type form its low, branched cushion habit, woody stems at the base, and short leaves arranged in terminal star-shaped rosettes. However, it is distinguished by broader, flatter leaves with a distinctly tuberculate surface beneath the silvery-grey tomentum that covers them, giving a rougher and more granular texture to the touch and eye than Celmisia ramulosa. The green of the foliage shows more between the hairs, giving the plant a grey-green hue that is less uniformly silvery.
The overall habit is slightly more spreading, adapting flexibly to the interstices of block chaos and coarse screes where it naturally settles.
In its natural habitat, flowering extends from December to February, with white capitula with yellow discs comparable to those of the type form. In cultivation under our latitudes, it generally blooms in June-July.
It requires perfect drainage, full sun exposure, and protection from stagnant winter moisture, conditions essential for its longevity in alpine rockeries.