Triteleia grandiflora is a perennial herb growing from a corm. It produces two or three basal leaves up to 70 centimetres (28 in) long by 1 cm wide. The inflorescence arises on a smooth, erect stem up to 75 cm (30 in) tall and bears an umbel-like cluster of many blue to white flowers. Each flower is a funnel-shaped bloom borne on a pedicel up to 4 or 5 cm long. The flower may be up to 3.5 cm long including the tubular throat and six tepals each just over 1 cm long. The inner set of three tepals are somewhat ruffled and broader than the outer tepals. The flower corolla may be deep blue to almost white with a darker blue mid-vein. There are six stamens with purple or yellow anthers. The prominent tubular flower throat distinguishes T. grandiflora from Triteleia hyacinthina, whose range overlaps T. grandiflora.
