Introduced by George Forrest in 1906 from the Lijiang Range in N.W. Yunnan who described it as "One of the most beautiful plants of W. Yunnan where it frequently smothers the ledges and faces of limestone cliffs and out cropping rocks with golden yellow or orange. Although it is mostly quite low and sometimes so tightly ad pressed to the rocks that the stems become flattened it may, on the other hand, under favourable conditions, grow up into small erect bushes over 1 metre high and with straight elongated branches."
Named Daphne aurantiaca in 1912, the low congest forms were subsequently separated from the open erect bushes under Daphne calcicola in 1914. Although this division is not accepted in the Flora of China it is used here as a convenient way to identify those compact forms which are of special interest to gardeners. Early introductions do not seem to have lasted the course as garden plants and with this in mind two questions need to be answered with re-introduced material; will Daphne calcicola maintain its dwarf congested character in cultivation and is it reasonably hardy in Britain.
During a visit to N.W. Yunnan in 1996 we saw D. calcicola in full flower between 1 - 7 June growing at altitudes between 3100 and 3300 metres; first in the Yulong Shan and then as we headed north in several sites on the Zhongdien Plateau. It was quite variable in leaf, flower colour and compactness but was distinct in habit from the taller open bushes of D. aurantiaca. On 18 June we returned to the Yulong Shan by which time seed was already developing on the Daphne. Small woody scions were collected from 7 of the most compact forms of D. calcicola growing in limestone rubble, amongst open pine trees, at about 3100m on the floor of the Gang Ho Ba. Three days later on 21 June the scions were delivered to Blackthorn Nursery and Sue and Robin White successfully established 6 clones. These initially produced alarmingly vigorous shoots and it seemed that any compactness would be lost, but that is not quite how it has turned out.
Two of the clones were selected and named; 'Sichuan Gold' (above) for compactness and freedom of flowering and 'Gang Ho Ba' (left) with the largest leaves and flowers. I received a plant of each in May 2001 on their own roots and these are now in their sixth winter in the garden measuring 40 cms high x 75 cms across and 45 cms x 85 cms respectively. They have flowered freely and become increasingly dense with 'Sichuan Gold' noticeably more so; the vigorous growth seen in young plants is absent. They have withstood -9°C without apparent damage in positions where they are in full sun with their roots under blocks of tufa in a sandy slightly acid soil. Year old cuttings planted out on the rock garden have established well but have thrown out vigorous shoots; I have pruned these to encourage compact growth and assume that in time, like their parents, they will develop a denser and more moderate form of growth.
I see that Highland Flowers of Yunnan (Yunnan Science and Technology Press, 1998) gives an altitude range of 2800 - 4400 metres for D. aurantiaca (which will include D. calcicola). There would be merit in trying to introduce D. calcicola from further north in its distribution and from greater altitude, for with the southern part of Yunnan bordering on the tropics, the material collected in the Gang Ho Ba may be insufficiently hardy to withstand a reasonably severe British winter without protection.