Cyanotis tuberosa Schult. f. Syst. Veg. 7: 1153. 1830; Clarke in: DC., Mon. Phan. 249. 1981; Cooke, Fl. Pres. Bombay 3: 302. 1906; Matthew, Fl. Tamilnadu Carnatic 365, 1981; Matthew & Britto, Fl. Tamilnadu Carnatic 3: 1963. Type: India. Tradescantia tuberosa Roxb., Pl. Cor. T. 108, 1798.
Roseete perennial, erect to ascending herb. Root tuberous, 3-8 cm. Reproductive shoots arise from the base of the rosette. Stem green hirsute Stem green, hirsute; internodes 2 - 9.5 cm. Rosette leaves distichous, green; sheath 1.4- 5.5. cm, hirsute, mouth ciliate, lamina linear- lanceolate, 20 - 39 x 2.5 – 3 cm, margin ciliate, upper surface glabrous lower surface hirsute, apex acute. Cauline leaves distichous, green; sheath 0.7 – 2.5 cm, hirsute, mouth ciliate, lamina linear – lanceolate, 3 – 13 x 1.5 – 2 cm, margins ciliate, upper surface glabrous, lower surface hirsute, apex acute. Cymes terminal or axillary, peduncles 0.5 – 3 cm, hirsute with a band of dense cilia opposite the bract. Bracts foliaceous green or purple, lanceolate – ovate, 1 – 2.5 x 0.3 – 0. 7cm, base chordate, margin ciliate, hirsute, apex acute. Bracteoles green or purple, ovate to falcate, 0.4 – 1.4 x 0.3 – 0.9 cm, margins ciliate, hirsute exposed areas purple in colour, apex acute. Sepals 3, pale white, lanceolate, up to 5.25 x 1mm, basally connate, margins ciliate, hirsute. Petals 3, blue violet or purple, 7- 7.5 x 3 – 3.25mm, fused, margins entire, glabrous. Stamens 6, up to 1.1cm long blue, bearded, hairs blue to violet, sub apical bulging; anther lobe yellow. Ovary 1 – 1.4 x 1x 1.1mm, pale green, ovate, hairy, densely ciliate; style violet – blue, sub apical bulging; stigma simple. Capsule 0.35 x 0.2 cm, stramineous with dark brown streaks, ovate, apex ciliate, glabrous elsewhere. Seeds 1.52 x 1.25 – 1.3mm, pyramidal, pale brown –brown or grey or reddish, tests reticulate, shallowly and irregularly pitted; hilum ventral, rounded, embryotega terminal.