A large, rounded, deciduous shrub 15 to 20 ft high, or a small tree; branchlets at first covered with pale down, becoming glabrous. Leaves 3 to 5 in. long, 1 to 2 in. wide; narrowly oval or obovate, deep dull green and glabrous above, pale and very woolly beneath when young, becoming almost glabrous by autumn. Flowers white, 1⁄3 in. across, produced very numerously in flatfish corymbs 2 in. or more across, terminating short leafy twigs; flower-stalks very woolly. Fruits in large clusters, each fruit about the size of a pea, rich bright red, with two nutlets.
Native of the Himalaya; introduced in 1824, and one of the most striking of all cotoneasters. The splendid clusters of ‘berries’ wreathing the branches make one of the most brilliant sights of autumn and early winter. The species is one of the most robust in the genus, making if left to itself a huge bush 20 ft high and as much through, consisting of numerous branching stems. But if kept to one stem when young and the lower branches removed, it will make a pretty round-headed tree with a well-shaped trunk. At Westonbirt, Glos., it has attained 40 ft in height. No hardy shrub more beautiful than this thrives in town gardens.
f. fructu-luteo (Bean) Rehd. – Fruits yellowish or creamy white; rare and little known, but not so beautiful as the type.
cv. ‘Pendulus’. – Branches pendulous; raised at Kew from seed obtained from Darjeeling in 1924.
cv. ‘Vicarii’. – An improved form raised by the late Hon. Vicary Gibbs at Aldenham.
C. frigidus has crossed spontaneously in gardens with C. salicifolius and its allies and some others of the Section Chaenopetalum. In this way some fine garden plants have arisen, of which the following are in commerce:
C. ‘Cornubia’. – This is one of the very finest of the larger growing cotoneasters. It is a very spreading shrub up to 25 ft high and more in width, clothed to the ground with foliage. But by pruning and keeping it to one stem in the early stages, it may be made to develop a genuine tree-like form. The richly green, abundant leaves are 4 to 5 in. long, oval-lanceolate, pointed, glabrous above, slightly downy beneath. It bears enormous crops of brilliant red fruits and is not surpassed in that respect by any other cotoneaster. It received an Award of Merit in 1933 and a First Class Certificate three years later. It was raised at Exbury and is perhaps a hybrid between C. frigidus ‘Vicarii’ and a plant grown as “C. glabratus” which was probably itself a hybrid of C. frigidus with a member of the C. salicifolius group (Orn. Fl. Trees & Shrubs, R.H.S. Conf. Rep., 1940, pp. 74 and 77). Two forms of the cross were distributed but the name ‘Cornubia’ belongs to the one given the A.M. in 1933. The original plant at Exbury is 25 ft high and 20 ft across.
C. × crispii Exell – This hybrid arose from C. frigidus by open pollination in the nurseries of John Waterer and Sons. The other parent was thought by Exell to be C. pannosus, which it resembles in leaf, while tending to C. frigidus in its fruits.
C. (frigidus × salicifolius) ‘Exburiensis’. – A tall evergreen shrub of which the first parent was a yellow-fruited form of C. frigidus. Leaves narrowly lanceolate, to 5 in. long and 1 in. or a little more wide, with impressed veins. Fruit pale yellow ‘Rothschildianus’ is another form of the cross, rather weaker growing, with deeper yellow fruits.
C. ‘Hybridus Pendulus’. – A vigorous shrub with slender, prostrate or arching branches which quickly makes a wide mat; if top-grafted, it makes a small weeping tree. Leaves medium green, slightly glossy, elliptic, acute, to about 3 in. long and 1 in. or slightly more wide. The red fruits are borne with great freedom in small cymes. The parentage and origin are both uncertain. Probably C. frigidus is one parent. The trailing habit suggests that C. dammeri might be the other, but another possibility is some species of the C. salicifolius group, in which prostrate seedlings have not infrequently occurred.
C. ‘Saint Monica’. – A semi-evergreen shrub to about 15 ft high, with leaves to 6 in. long, bearing its fruit in long pendulous clusters. It was raised from C. frigidus at the Saint Monica Home, Bristol, and given an Award of Merit in 1933.
C. × watereri Exell – This fine shrub is a hybrid between C. frigidus and C. henryanus. It appeared as a chance seedling from frigidus in John Waterer and Son’s nurseries at Bagshot and was described and named in 1928. Recently the clonal name ‘John Waterer’ has been given to the original plant and its descendants by vegetative propagation, in order to distinguish them from seedlings and from other cotoneasters that might arise from the same parents. It is an evergreen or semi-evergreen shrub with narrowly elliptic leaves 11⁄2 to 3 in. long, tapered about equally towards both ends, dark dull green, glabrous at maturity, veins about twelve each side the midrib. Fruits globose, scarlet, 1⁄4 in. wide, borne in corymbose clusters 11⁄2 to 2 in. across. Bot. Mag., n.s., t. 282. Discussing this hybrid (loc. cit.) Dr Turrill remarked, ‘On the whole, it seems that the characters of C. henryanus are strongly predominant in the supposed hybrid.’ In view of this considered judgement it is scarcely correct to adopt C. × watereri as the group-name for hybrids between C. frigidus and C. salicifolius, as has been done by continental authorities. Doubtless the latter species and C. henryanus are near allies, but are generally held to be specifically distinct.