Pernettya mucronata (L.f.) Gaud.
Synonyms: Arbutus mucronata L.f.
An evergreen shrub 2 to 5 ft high, spreading freely by suckers and forming ultimately a dense, low thicket; young branches thin and wiry, sometimes furnished with a few appressed, forward-pointing bristles or short down, but usually becoming glabrous in a short time. Leaves alternate, dense upon the branches, ovate to oblong, very shortly stalked, 1⁄3 to 3⁄4 in. long, 1⁄8 to 1⁄4 in. wide, toothed and spiny-pointed, hard in texture, lateral veins scarcely visible on the underside. Flowers produced singly in the leaf-axils near the end of the shoot, in May. Corolla white, nodding, cylindrical, about 1⁄4 in. long, five-toothed. Calyx five-lobed, green; stamens ten; flower-stalk 1⁄4 in. long. Fruit a globose berry 1⁄3 to 1⁄2 in. diameter, containing many very small seeds; it varies in colour from pure white to pink, lilac, crimson, and purple, or almost black; calyx not fleshy.
Native of Chile and bordering parts of Argentina from Cape Horn northward to around 40° S.; introduced in 1828, from the region of the Straits of Magellan. This is one of the hardiest of S. American shrubs, and is rarely severely injured by frost in the neighbourhood of London. Certainly it is one of the finest ornamental berry-bearing shrubs we have. Its berries attain their colour by early autumn, and remain on the branches through the winter and following spring. (See further below, in the note on the garden varieties.)
P. mucronata and its garden varieties need a light, peaty soil and like full sunshine.
var. rupicola (Phil.) Reiche P. rupicola Phil. – Leaves rather thinner than in typical P. mucronata, more or less elliptic, 3⁄8 to 1⁄2 in. long, scarcely 3⁄16 in. wide. Native of the island of Chiloe and of the bordering mainland. Probably introduced in the 1830s.
P. mucronata was for long strangely neglected in gardens, but a great fillip to its cultivation was given by an exhibit in London made about 1882 by the Irish nurseryman T. Davis of Hillsborough in Co. Down, who showed a number of remarkably beautiful varieties he had raised during the previous thirty years. According to his own account the original parent was ‘the hardiest and most free-flowering variety of P. mucronata, namely var. angustifolia’. Whether this plant was really the true P. angustifolia Lindl. it is impossible to say. According to Davis, among the original seedlings from this plant were several that varied considerably from the ‘type’ in foliage as well as in colour of berries.
The plants shown in 1882 ranged in colour from white through shades of pink and red to almost black, and some were given distinguishing epithets in Latin. The plants offered in commerce at the present time as Davis’s Hybrids appear to be seedlings or later selections, some of which have been given cultivar names. One of the best known clones is ‘Bell’s Seedling’, raised in Ireland, with large, long-persisting fruits of a bright carmine-red. But many others are listed by nurserymen. Seven named varieties raised in Holland were given awards at Boskoop in 1968 (Dendroflora, No. 6, p. 56).
It may be mentioned here that many if not all of the plants of P. mucronata have been found to be functionally, if not structurally, unisexual, and that to get the best results they should be planted in groups, with a few certified male plants mixed with named female clones, at the rate of about one male to five or at the most ten females. This statement is based on the researches of the Dutch botanist Dr B. K. Boom, carried out in the 1930s on behalf of the Boskoop nurserymen, who had found that their varieties of P. mucronata were producing less and less fruit every year. The explanation was, of course, that by selecting the best fruiting varieties they had eliminated most of the pollinators. Male clones are now offered by most nurserymen who list P. mucronata.
A very distinct form of P. mucronata is offered by Messrs Hillier under the cultivar-name ‘Edward Balls’. It has stout, erect branches densely set with imbricated, ovate or triangular-ovate leaves about 5⁄8 in. long, with pronounced terminal spines. Its origin is unknown.
P. angustifolia Lindl. P. mucronata var. angustifolia (Lindl.) Reiche – This pernettya was described by Lindley in 1840 from plants raised from Chilean seed (Bot. Reg., Vol. 26, t. 63). He did not compare it with P. mucronata, from which it differs obviously in the shortness or virtual absence of the terminal spine. Some of the specimens in the Kew Herbarium originally referred to P. angustifolia belong to P. prostrata subsp. pentlandii. Others agree with P. mucronata but have narrowly elliptic leaves. Some appear to be intermediate and might be hybrids, as P. angustifolia itself possibly is. The Chilean pernettyas occurring from the latitude of Chiloe island northward appear to be very variable and are in need of further study.