Diagnosis: Colocasia hassanii H. Ara is closely related to C. esculenta (L.) Schott but can be easily differentiated by the number of constriction (two) present in spathe, presence of sterile male zone in spadix and bitter in taste. Bengali name: Tita Kachu. English name: Bitter Taro (proposed). Holotype: Bangladesh, Bandarban district, on the way to Betchari, 22.9.2004, Hosne Ara HA 1215, 1216 (DACB). Annual herb. Underground corm perennial, c. 2.5 cm in diam., and c. 2 cm high; stolons 1–2, trailing horizontally, non-branching, thin, pale green or pale purple, c. 20 cm long, c. 0.5 cm in diam. Leaves 4–6, peltate, 15–45×8–30 cm, ovate, acute, cordate, dark green above and light green beneath, base shallowly cordate, glaucous, venation pinnately reticulate, sinus 1–3 cm long; petiole 20–65 cm long, sheathing for about one-third at the base. Inflorescence solitary or paired. Peduncle 10–14 cm long, shorter than petiole. Spathe having two constrictions, 15.0–25.5 cm long, lower convolute part (tube) light green, 4.0–6.5 cm long, c. 2 cm in diam., nearly cylindrical; upper part lanceolate, light yellow, 11–19 cm long. Spadix sessile, shorter than spathe, 10–19 cm long. Female zone cylindrical, 2.8–3.0 cm long, c. 1 cm in diam.; staminode c. 1.8 cm long, creamy; sterile portion slender, c. 1.8 cm long, c. 0.4 cm broad at the middle, creamy; male portion 2.1–2.8 cm long, 0.4–0.5 cm in diam.; a sterile male portion present below the appendix, 0.4–0.5 cm long, c. 0.2 cm in diam.; appendix 6.5–10.0 cm long, 0.3–0.5 cm in diam. Ovary numerous, narrow, green, 3–5×2–3 mm; style very short, green; stigma c. 0.05 cm in diam., yellow, placentation parietal, ovules 6, c. 1.5×1.0 mm; staminode cream in colour, c. 0.15×0.2 cm; male flower 6-8 androus, c. 0.1×0.12 cm. Fruit a berry. Flowering and fruiting period: June to October. Ecology: Grows in the hilly areas as undergrowth. Distribution: Eastern hilly areas of Bangladesh (Bandarban, Khagrachari and Rangamati hill districts), Cox’s Bazar and Moulvibazar districts.