This species was first raised in this country by A. K. Bulley from seed sent to him by Polhill-Turner, a missionary stationed at Tatsien-lu, W. China, whose name it first bore in gardens. The first valid description of it was given in the Journal of Botany, 1906, p. 7, in an article on the genus by Sir David Prain, when it was named C. minus.
It is a deciduous shrub usually 11⁄2 to 3 ft high, with obovate leaves rounded or blunt at the apex, tapered to a very short stalk, 3⁄4 to 11⁄2 in. long, scaly and with appressed bristles beneath, glabrous or nearly so above, bristly on the margins. The flowers are closely packed in terminal and axillary heads on which they open successively from late summer to October. Wilson, Forrest, and Kingdon Ward all describe them as ‘bright blue’, and the last-named says in addition ‘calyx crimson’. The plants cultivated in the R.H.S. Garden at Wisley bear pale blue flowers. The inflorescence is furnished with spiky bracts like the other species.
The species is most nearly allied to C. griffithii, but that is very distinct by reason of the bristly character of the upper surface of the leaf. C. willmottianum is also bristly on both surfaces of its leaves, and they are lanceolate to rhomboid in shape and always tapered at the apex. Delavay first found C. minus in Yunnan about 1884, where Forrest also collected it later. Wilson saw it in Szechwan. In hardiness it is intermediate between the other two; that is to say it will be happiest in the sunny gardens of the south, and best planted against a wall.