Cyanea konahuanuiensis is an unarmed shrub with a height of 0.5-0.75 meters, characterized by 1–6 stems originating from the base. The stems transition in color from light green to light brownish gray towards the base and range from erect to decumbent, measuring 58–119 cm in length. Some branches may rest on the ground and occasionally root upon contact with soil or moss, producing aerial roots. The leaf scars are sub-circular, featuring a depressed upper end and a slightly raised basal portion, each with a protuberance. The plant exudes white latex. The leaves are simple and clustered towards the end of the stems. Adult plants have elliptic to oblong blades measuring 20–33 cm in length and 10–16 cm in width, with an acute to sub-obtuse apex and a cuneate to rounded base, sometimes slightly truncate. The leaf’s surfaces are dull grayish-green on the adaxial side and dull greenish-white on the abaxial side, stiff and somewhat fleshy, covered densely with hirsute and minutely muricate hairs. Juvenile plants exhibit less stiff leaves with dentate margins and softer hairs. The leaf margins range from serrate to serrate-dentate, and petioles are 2–4.2 cm long and pubescent. It produces axillary inflorescences just above the leaves, with each stem hosting up to 4. These inflorescences are initially roughly perpendicular to the stem but become pendant as they develop, containing 3–12 flowers each, on peduncles measuring 5–12.2 cm long. The flowers are bisexual (perfect), with calyx lobes that are linear to linear-oblong and have an acute apex to sub-obtuse. The corolla is dark purple, tubular, laterally compressed, and curved, measuring 86–99 mm in length and 12–13 mm in width, with linear-subulate lobes that are reflexed and constitute about a quarter to a third of the tube’s length. The plant has five connate stamens, with anthers that are scantily pubescent and bear apical tufts of white hairs. The seeds are numerous and obovoid, measuring 0.5 mm in length, with a medium to dark brown, shiny, and smooth seed coat. It occurs in wet forest environments at elevations between 884-932 meters.