Buddleja blattaria is a dioecious shrub, < 1 m tall, with brown fissured bark. The young branches are quadrangular and covered with thick tomentum. The leaves are sessile elliptic or oblong-elliptic, 4–10 cm long by 1.5–3 cm wide, lanose on both surfaces. The white or cream inflorescence is 3–8 cm long, comprising sessile flowers borne on one terminal and 1–3 pairs of globose heads below, in the axils of small leaves, each head 1–2 cm diameter with 20–40 flowers, the corolla 5 mm long.
The species is very similar to B. jamesonii found to the north in southern Ecuador but differs from the latter in having larger leaves with crenate margins, and lacks the foliose axillary branches. B. jamesonii is also trioecious.
The shrub is not known to be in cultivation.
- Norman, E. M. (2000). Buddlejaceae. Flora Neotropica 81. New York Botanical Garden, USA
- Macbride, J. F. (1934) Candollea 5: 399, 1934.