Melicope kaalaensis is a small or medium-sized tree that reaches 3 to 7 m tall. New growth tends to have densely yellowish-white tomentose with a waxy scurf. Leaves with a strong anise odor, opposite, coriaceous, ovate-elliptic, oblong-ovate, or broadly oblong-elliptic, 4-23 cm long, 2-9.5 cm wide, lateral veins usually 10-18 pairs, prominent on the lower surface, slightly ascending, connected by a slightly arched vein usually 2-7 mm from the margin, upper surface dark and glossy, glabrous, lower surface paler with reddish-brown veins, sparsely to moderately puberulent, more densely so along midrib, sometimes becoming sparsely so with age, apex acute to obtuse and usually mucronulate, base weakly cordate or rounded, petioles stout, 10-35 mm long, usually puberulent. The flowers are 4-9 in cymes, puberulent throughout, peduncles 15-95 mm long, pedicels 5-12 mm long; staminate flowers with sepals ovate, ca. 5 mm long, puberulent, petals delicate-ovate, ca. 8 mm long, puberulent externally, glabrous within, ovary and nectary disk reduced, puberulent, style short-hirtellous; pistillate flowers with sepals ovate, ca. 4 mm long, puberulent, petals pinkish, deltate-ovate, ca. 7 mm long, 4-5 mm wide, puberulent externally, glabrous within, stamens rudimentary, ovary densely yellowish pubescent, on a slightly paler, puberulent nectary disk, style ca. 3.5 mm long, hirtellous. The fruits are green capsules, 20-35 mm wide, carpels connate 1/3-1/2 their length, 9-17 mm long, reflexed after dehiscence, exocarp puberulent, endocarp densely puberulent. The seeds are 1–2 per carpel; they are 6–8 mm long. glossy black when ripe; crustaceous; ovoid; sometimes angled from compression; embryo straight in fleshy endosperm; radicle short; cotyledons compressed; ovate; putamen brown; warty. It occurs in mesic and wet forests between 520-860 meters.