Xanthosia tasmanica is an erect or ascending perennial herb that typically grows to a height of and has a few long spreading hairs on its stems and leaves. Its leaves are trifoliate, the leaflets elliptic or wedge-shaped, long and wide on a
petiole up to long. The flowers are arranged in a
compound umbel with up to 4 rays with one flower per ray and sometimes one flower between the rays. There are up to four linear, leaf-like
bracts long at the base of the flowers and leaf-like green
bracteoles long at the base of the
peduncles. The
sepals are green, long and the petals are white, shorter than the sepals, about long. Flowering occurs in most months with a peak in spring. ==Taxonomy and naming==