Enkianthus. in cultivation. Enkianthus bring a welcome. Koen Camelbeke provide an overview of the cultivated species and detail the cultivars

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1 Enkianthus campanulatus Showy Lantern Enkianthus in cultivation Th o m a s Clark, Eric Hsu and Koen Camelbeke provide an overview of the cultivated species and detail the cultivars Enkianthus bring a welcome subtlety to the spring garden. Their small flowers and leaves contrast with those of their more blousy ericaceous brethren such as Rhododendron, and they demand less cultivation attention. The genus contains species, augmented by several worthwhile cultivars. Genus characteristics The pendulous, umbel-like clusters or racemes of campanulate flowers resemble those of related genera such as Gaultheria and Vaccinium. However, the dry capsules, rather than fleshy berries, and whorl-like arrangement of toothed leaves and branches, differentiate Enkianthus. They are deciduous shrubs or small trees and flowering occurs in early to late spring, April to June in the northern hemisphere. The native range of the genus is east Asia, occupying a broad swathe from the eastern Himalayas to southeast Asia, and north into China and Japan. China is host to seven species, more than any other country, four of which are endemic (Ruizheng & Stevens 2005). These species are E. chinensis, E. deflexus, E. pauciflorus, E. perulatus (syn. E. taiwanianus), E. quinqueflorus, E. serotinus and E. serrulatus. Three are native to Japan: E. campanulatus, E. cernuus and E. perulatus. Taxonomic history The genus was established in 1790 by João de Loureiro ( ), a Portuguese Jesuit missionary, palaeontologist, physician and botanist who resided in Cochinchina (now Vietnam) for 30 years. Taking cues from the flowers, he created the genus name from the Greek words enkyos, pregnant, and anthos, flowers. 78 June 2011

2 The Plantsman Thomas Clark Enkianthus campanulatus flowering profusely in early May. It will eventually form a large shrub Enkianthus campanulatus var. palibinii Morphological and phylogenetic analyses show that Enkianthus is a sister group to other ericaceous taxa, and is the only extant representative of subfamily Enkianthoideae, one of the two evolutionary lineages in the family (Anderberg 1993, Judd & Kron 1993, Kron & Chase 1993). Four sections are currently recognized within the genus: section Andromedina (E. nudipes, E. subsessilis); section Enkiantella (E. chinensis, E. deflexus, E. pauciflorus, E. ruber); section Enkianthus (E. perulatus, E. quinqueflorus, E. serotinus, E. serrulatus, E. taiwanianus, E. tubulatus); and June 2011 section Meisteria (E. campanulatus, E. cernuus) (Anderberg 1994). Less clear-cut, and still controversial, is the number of species in the genus. Nine species were recognized by Palibin (1889) while more recent treatments vary: 13 (Hsu 1982), 17 (Anderberg 1994), 15 (Kron et al. 2002), 12 (Ruizheng & Stevens 2005). Species and cultivars Enkianthus campanulatus (redvein enkianthus) This is the most widely cultivated species, introduced to the UK from Japan by Charles Maries on behalf of Messrs Veitch nurseries. Of the endemic Japanese species it has the widest distribution, ranging from southern Hokkaido to Honshu and Shikoku, where it colonizes open mountainous slopes. Its morpho logical variability is recognized in four varieties; var. campanulatus, var. longilobus, var. palibinii and var. sikokianus. The first three are largely distinguished by their corolla length (7 8mm in var. campanulatus, 8 9mm in var. longilobus and 5 6mm in var. palibinii) (Iwatsuki & Boufford 1993). Var. campanulatus Enkianthus campanulatus f. albiflorus has pale yellow to reddish, striated flowers while those of var. palibinii are entirely red. A white-flowered variant has been accorded its own form, f. albiflorus. Iwatsuki & Boufford (1993) elevate var. sikokianus to species status, E. sikokianus, but in horticulture it is usually recognized at varietal level. It is easily differen tiated from the other varieties in having longer racemes, up to 9cm, and 8 20 flowers per raceme instead of 10 or less (Iwatsuki & Boufford 1993). In Europe and North America this species forms a medium to large shrub, although older plants can be considered small, multi-stemmed trees. A giant 47-year-old specimen at Polly Hill Arboretum, Massachusetts, measured 9.4m tall by 12.2m wide in The autumn foliage reliably provides a spectacular and vibrant display ranging from yellow to orange and crimson. Individual clones are variable in habit and vigour, but the natural shape of this species is generally upright and taller than wide in youth, but spreading with age. The cultivars of E. campanulatus that the authors have been able 79

3 genus profile to observe are discussed here. A comprehensive evaluation of the available ones would be invaluable for the horticulture industry. Deep pink- and red-flowered cultivars n Akatsuki This cultivar produces mid-pink flowers, echoing its name which means dawn. It is one of several Japanese cultivars imported into North America within the last 10 years by Heritage Seedlings, Inc., Oregon. n Bruce Briggs This is one of the darkest redflowered cultivars. It is a recent selection from Weston Nurseries, Massachusetts, named for a visionary Washington state nurseryman. It has been listed informally as Weston red or Weston red seedling. n Donardensis Its flowers are rimmed in deep red and twice as large as the typical species. It arose as a chance seedling at Slieve Donard Nursery, Northern Ireland, before n Hollandia This cultivar bears pale, creamy pink flowers with heavy rose-pink venation. It is frequently listed as Hollandia Red. n Jan Iseli Pink and Jan Iseli Red The former produces dense clusters of round, cream-coloured flowers Enkianthus campanulatus has yielded the most cultivars, with flowers in a range of colours. From left to right: Red Velvet, Green Shades and Faser s Picotee etched with rose-pink veining, whereas the latter has rose-red flowers that are darker and with even darker venation than Showy Lantern. These cultivars were introduced in 1990 and originated from a 1980s breeding program at Iseli Nursery, Oregon. They were named for the wife of the nursery s founder. n Miyama-beni This vigorous cultivar has rose-pink flowers. Like Akatsuki, it was imported from Japan by Heritage Seedlings, Inc. n Princeton Red Bells This is a distinctive cultivar with the darkest red flowers of any E. campanulatus cultivar. It was introduced in the late 1970s by Bill Flemer III of Princeton Nurseries, New Jersey. n Red Bells Do not confuse this with Princeton Red Bells ; it has unremarkable flowers typical of the species. n Red Velvet The rose pink flowers are similar to those of Miyama-beni and Showy Lantern, but it has consistently good red autumn foliage. n Showy Lantern This densely-branched cultivar has slender, rich rose-pink flowers with darker veining and scarlet autumn foliage. Cappiello & Littlefield (1994) suggest that it is less coldhardy than the species. It was named and introduced in the 1980s by the late Ed Mezitt of Weston Nurseries. White- and cream-flowered cultivars Some clones of E. campanulatus f. albiflorus have pure white flowers with no hint of coloured veining and are particularly elegant. n Renoir This cultivar has creamy white flowers with subtly pink-tipped corolla lobes and no veining. It originated at the Arnold Arboretum, Massachusetts, where it had been grown from seed received in 1923 from University of Edinburgh, Scotland. It was named by assistant propagator Rob Nicholson in the early 1980s (Nicholson 1983). The original plant no longer grows at the Arnold Arboretum, having been deaccessioned in n Wallaby This cultivar bears creamy white flowers and is a dwarf, compact selection with deep scarlet autumn foliage. It is not a vigorous grower at Arboretum Wespelaar, Belgium. Variegated cultivars n Tokyo Masquerade This cultivar has medium green leaves that are irregularly edged in chartreuse green; the edge colour later fades to ivory white. Variegata is probably a synonym, although other distinct variegated clones, 80 June 2011

4 The Plantsman The autumn foliage of Enkianthus campanulatus on Mount Sanpokojin in northwest Honshu, Japan including one with white speckled leaves, have been selected, as has a golden-leaved one. Other cultivars n Faser s Picotee Creamy white flowers with contrasting pink-edged lobes distinguish this 2006 introduction from Rare Find Nursery, New Jersey. The promising seedling was named by the late nursery founder, Hank Schannen, for Mrs Faser, who distinguished it from a patch of volunteer seedlings. n Green Shades The small flowers of this cultivar are edged in pink and are greenish near the sepals, but it is rather inconspicuous from a distance. n Summer Hill Selected from a chance seedling, this Enkianthus cernuus cultivar is noted for its larger leaves, strong upright growth, and white flowers marked with a rich rose-red band on the apical third of the corolla. The new stems emerge an attractive reddish colour. It was selected by Mike Johnson of Summer Hill Nursery, Connecticut. We have traced the following cultivar names in nursery catalogues and inventories of various public gardens, although none of them have been observed by the authors: Chichibu-beni, Compactus, Fukurin-beni, Hiraethlyn, Howito, Iwa-shidare, Kisoji-noharu, Kuchibeni-nishiki, Pagoda (possibly a corruption of the common name, pagoda bush), Red Beauty, Ruby Glow, Shidare-beni, Sinsetsu, Enkianthus cernuus f. rubens Venus, Vesta, Virgo, Victoria and a weeping form. There are undoubtedly many other selections from various countries, Japan in particular, and some of which are gradually finding their way into North American and European gardens. Enkianthus cernuus (nodding enkianthus) Native to the mountainous parts of Honshu, Japan, E. cernuus is distinguished from E. campanulatus by its dissected calyx lobes, smaller stature ( m), smaller leaves (2 4 x 1 5cm) and smaller, white flowers (0.6cm long) borne fewer per cluster (5 12). At least one variety, E. cernuus var. matsudae, is distinguished by its narrower, lanceolate leaves, less pubescent leaf midribs, and narrower and red flowers. A second variety, E. cernuus var. nipponicus, cultivated in several US arboreta, is considered synonymous with E. cernuus by Ohwi (1965). A colour form, E. cernuus f. rubens, notable for its dark red flowers, is the most widespread enkianthus in cultivation after E. campanulatus and E. perulatus. Its size and habit is more similar to E. perulatus and only the reddest forms of E. campanulatus rival its red flowers. The corolla of f. rubens is unique in that the widest point is near the middle and the distal ends of the petals curve inward, giving the flowers a rather globular shape, as opposed to the bell-shaped flowers characteristic of the genus. Enkianthus cernuus f. rubens is less hardy than the species, and most of the other species in the genus, in central Belgium. Cold winters have killed young plants of this forma and left older plants with major stem damage from frost. It therefore requires a protected site in such climates. Nevertheless, the performance of established plants has been mostly impressive. June

5 genus profile The narrow leaves of Enkianthus cernuus Yanagiba n The cultivar Yanagiba has small spherical flowers that are deep red. However, it is the narrow leaves giving a feathery effect that make Yanagiba one of the most distinctive enkianthuses; at first glance it has the appearance of a cut-leaf Japanese maple. Selected and named in Japan, it was introduced to North America by Brian Upchurch of Highland Creek Nursery, North Carolina, and Ted Stephens of Nurseries Caroliniana, South Carolina. Enkianthus chinensis A shrub or small tree between 2.5 and 8m tall, E. chinensis colonizes the forested and mountainous areas of central and southern China at 900 1,200m, exceptionally reaching 3,100m (Ruizheng & Stevens 2005). Slightly smaller than those of E. deflexus, the leaves are 1.5cm wide and cm long (Ruizheng & Stevens 2005). The flowers, striped with yellow, orange and red, are 7 10mm wide and the autumn colour is early and superb. Enkianthus chinensis is rare in private gardens and only encountered infrequently in arboreta and botanic gardens. A plant acquired from Esveld nursery in the Netherlands is usually the last of the species to flower at Arboretum Wespelaar. At the University of British Columbia Botanical Garden, E. chinensis, originally collected during the 1980 Sino-American Botanical Expedition (as SABE 1311), has prospered and flowers generously (Wharton et al. 2005) Enkianthus deflexus This species is widely distributed in forests at 1,000 3,300m in China, Bhutan, northeast India, Burma, Nepal and Sikkim. It forms a shrub or a small tree 1.5 5m tall and the leaves are x cm (Stevens 1971). Bean (1973) stated that the flowers appear in June, but Ruizheng & Stevens (2005) note that flowering stretches from April to July. One variety, E. deflexus var. glabrescens, has been described it has leaves that are glabrous on both surfaces while in var. deflexus they are hairy on both surfaces. Plant hunter EH Wilson thought highly of E. deflexus, calling it one of the commonest and most beautiful shrubs in western Szech uan (Sargent 1988). Lancaster (1989) noted that the autumn colours were superb on the upper slopes of Emei Shan in Sichuan and that E. deflexus was the most brilliant of all. Enkianthus nudipes A Japanese endemic restricted to central Honshu and Shikoku, E. nudipes colonizes open areas at 400 1,000m (Iwatsuki & Boufford 1993). It forms a shrub 1 2m tall, with leaves x cm wide (Iwatsuki & Boufford 1993). Flowering occurs between mid May and mid June. The 4mm long, convallaria-like flowers are held on exceptionally long pedicels, giving an effect of delicate earrings. Curiously, this species is poorly represented in gardens for unknown reasons. It deserves further introduction and evaluation, and the long pedicels may be imparted The multicoloured flowers of Enkianthus chinensis to other species through breeding. Enkianthus perulatus (white enkianthus) This species favours rocky slopes in southern Honshu, Shikoku and Kyushu in Japan, and in northern Taiwan on the margins of Fagus hayatae forest. It is readily identifiable in mid spring since the flowers appear before the leaves. Sir Rutherford Alcock, the first British diplomat in Japan, discovered this species in Nagasaki in 1859, but its introduction did not take place until ten years later by Messrs Standish (Bean 1973). Enkianthus perulatus is the second most common species in cultivation. At a distance its flowers are of little consequence, but up close they are 82 June 2011 Tom Clark Enkianthus deflexus

6 The Plantsman The autumn colour of Enkianthus perulatus J.L. Pennock (above) and the flowers of the species (below) attractive and daintily elegant. The habit is variable, becoming either a loosely upright to rounded shrub or a tightly mounding, spreading shrub. The autumn colour is splendid and, at its best, is a brilliant red or a glowing yellowish orange. This excellent autumn colour and its adaptability to heavy pruning, even shearing, makes E. perulatus a logical substitute for Euonymus alatus in parts of northeast USA where the latter is invasive and threatens natural ecosystems. n J.L. Pennock The flowers of this cultivar are typical of the species, but the autumn display is outstanding both in colour and in its exceptional longevity. The colour begins as deep purple two weeks before other individuals of the same species and consistently peaks as bright red. Rick Lewandowski and Paul Meyer selected and named this cultivar from a cultivated research collection at the Morris Arboretum of the University of Pennsylvania in the 1980s and patented it in 1994 (Lewandowski et al. 1994). The original plant is a compact shrub, broader than tall, and at more than 50 years is less than 3m in height. Dillard (2003) provides detailed propagation information. Two small specimens of J.L. Pennock at Arboretum Wespelaar, given by the Morris Arboretum, are rated highly for their autumn colour. n Compactus This exceedingly compact cultivar has been in North American gardens for decades, but remains rare. It had a prominent presence at Larchmont, New York, the garden of the late plantsman Harold Epstein where it grew for more than 50 years and reached scarcely 0.6m tall. After Tony Aiello Epstein s death the 1m wide specimen was auctioned and transplanted to a private Connecticut garden. Another venerable specimen approaching 1m tall and 1.3m wide thrives at Wave Hill public garden, New York. Tsukumo is another dwarf selection. Enkianthus quinqueflorus This deciduous species can be easily recognized by its 1cm wide, translucent, pearly pink flowers and prominently raised leaf veins. Reaching 1 2m in height, this species inhabits hillsides and mixed forests in south China and north Vietnam at 600 1,500m (Ruizheng & Stevens 2005). Indeed, plants were observed by one author (E Hsu) in dry, rocky terrain in Hong Kong. Bean (1973) praised this species as unsurpassed among enkianthuses in the size and beauty of the individual flowers and the clusters with their attendant pink bracts give a charming effect. Symbolizing good fortune, large bunches of E. quinqueflorus were once harvested and forced for floral arrangements celebrating the Chinese New Year in late January or February (Metcalf 1942). It was a common practice in the Qing dynasty ( ) to place the cut branches in temples as deity offerings (Abel 1818, Goody 1993). However, this practice ceased when the species was placed under protection in 1925 (Jarrett 1932). Not surprisingly, its beauty, early discovery, and prominence in Chinese culture meant that it was the first Enkianthus species to be brought into cultivation in the West. It was introduced to North America in the early 19th century and by 1835 it was being successfully grown alongside camellias in the conservatory of Colonel TH Perkins near Boston, Massachusetts (Teschemacher 1835). Its lack of hardiness and need for glasshouse June

7 genus profile protection in frost-prone climates has prevented its widespread cultivation. However, hardiness trials could reveal hardier clones. n Pink Chandelier This cultivar was recently imported from Japan by Ted Stephens of Nurseries Caroliniana and has been propagated by semi-hardwood cuttings. A containerised plant has survived -10 C without damage (Stephens 2010). It flowers between mid March and early April. It is not clear how this cultivar differs from the species since published descriptions are not informative. Abel, C (1818) Narrative of a journey in the interior of China and of a voyage to and from that country in the years 1816 and Longman, Hurst, Rees, Orme and Brown, London Anderberg, AA (1993) Cladistic relationships and major clades of the Ericales. Pl. Syst. Evol. 184: Anderberg, AA (1994) Cladistic analysis of Enkianthus (Ericaceae) with notes on the early diversification of the Ericaceae. Nordic J. Bot. 14: Bean, WJ (1973) Trees and Shrubs Hardy in the British Isles. 8th edn. London, John Murray Cappiello, PE & Littlefield, LE (1994) Woody Landscape Plant Cold Hardiness Ratings. Maine Agricultural and Forestry Experiment Station Technical Bulletin 156. Orono, Maine Dillard, S (2003) Propagation of Enkianthus perulatus J.L. Pennock. The International Plant Propagators Society Combined Proceedings 53: 488 Dirr, M (2009) Manual of Woody Landscape Plants. 6th edn. Champaign, Illinois Goody, J (1993) The Culture of Flowers. Cambridge University Press, Cambridge Gossler, R, Gossler, E & Gossler, M (2009) The Gossler Guide to Best Hardy Shrubs. Timber Press, Oregon Hsu, T-Z (1982) Classification, distribution and phylogeny of the genus Enkianthus. Acta Bot. Yunnan. 4: Iwatsuki, K & Boufford, DE (1993) Flora of Japan. Kodansha, Tokyo Enkianthus serrulatus Like other Chinese species, E. serrulatus is a large shrub or small tree between 3 and 5m tall. It is native to mountainous forests at 800 1,800m in southeast and central China (Ruizheng & Stevens 2005). The elliptic leaves are 5 10 x 2 3cm and have finely toothed margins that differentiate E. serrulatus from other species. It has white flowers, similar to those of E. perulatus but larger. Enkianthus serrulatus is rare in cultivation, although JC Raulston of North Carolina State University references Jarrett, VHC (1932) The protection of wild plants in Hong Kong. Hong Kong Naturalist 3(2): Judd, WS & Kron, KA (1993) Circumscription of Ericaceae (Ericales) as determined by preliminary cladistic analyses based on morphological, anatomical, and embryological features. Brittonia 45(2): Kron, KA & Chase, MW (1993) Systematics of the Ericaceae, Empetraceae, Epacridaceae and related taxa based on rbcl sequence data. Ann. Missouri Bot. Gard. 80: Kron, KA, Judd, WS, Stevens, PF, Crayn, DM, Anderberg, AA, Gadek, PA, Quinn, CJ & Luteyn, JL (2002) Phylogenetic classification of Ericaceae: molecular and morphological evidence. Bot. Rev. 68: Lewandowski, RJ, Meyer, PW & Dillard, RJ (1994) Enkianthus perulatus J.L. Pennock. United States Plant Patent Number 8,901 Metcalf, FP (1942) Flowers of the Chinese New Year. Arnoldia 2(1): 1 8 Nicholson, R (1983) In: Alexander, J & Koller, G. New plant forum. The International Plant Propagators Society Combined Proceedings 33: 493 Ohwi, J (1965) Flora of Japan. Smithsonian Institution, Washington, DC Palibin, JV (1889) Revisio generis Enkianthus Lour. Bot. Zap. 15: 1 18 Rogers, C (1989) In: Alexander, J. New plant forum. The International Plant Propagators Society Combined Arboretum (now J.C. Raulston Arboretum) imported and distributed cuttings to various gardens and nurseries. Gossler et al. (2009) remark on its good performance under part-shade conditions, especially its healthy green foliage and good autumn colour. Conservation Ecological studies of Enkianthus are rare; therefore the conservation status of most species is not known. However, heavy grazing by Sika deer has affected populations of E. campanulatus, a species considered Proceedings 39: 558 Ruizheng, F & Stevens, PF (2005) Enkianthus. In: Flora of China Editorial Committee (eds) Flora of China. Vol. 14 (Apiaceae through Ericaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St Louis Sargent, CS (ed.) (1988) Plantae Wilsonianae. Vol. 1. Dioscorides Press, Oregon Stephens, T (2010) Innovative options in plant selections for southern gardens. htm (accessed March 2011) Stevens, PF (1971) A classification of the Ericaceae: subfamilies and tribes. Bot. J. Linn. Soc. 64: 1 53 Teschemacher, JE (1835) Horticulture near Boston. Hort. Reg. & Gard. Mag. 1(3): Wharton, P, Hine, B & Justice, D (2005) The Jade Garden. Timber Press, Oregon Yang, J-F, Liu, X-Y, Zhang, S-Z & Huang, Y-X (2009) Tissue culture of Enkianthus quinqueflorus Lour. J. Trop. Subtrop. Bot. 17(4): Yoshino, Y, Maeda, M, Yamase, K & Ueyama, Y (2005) Studies on conservation of endangered species Enkianthus campanulatus, 1: Distribution of habitats and growth of Enkianthus campanulatus in Hyogo prefecture (Japan). Bulletin of the Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries. Forestry Section 52: June 2011

8 The Plantsman endangered in Japan (Yoshino et al. 2005). It is likely that Chinese species are suffering from deforestation and development. Propagation Fortunately, unlike other plants uncommon in cultivation, Enkianthus are not difficult to propagate from seed. Cuttings can be a bit more of a challenge. The seed capsules are beige to dark brown, 6 19mm in diameter, and ripen in the autumn (September to October). Between three and five dust-like seeds are produced in each capsule. They do not require pregermination treatment, prompting Dirr (2009) to liken them to sowing beans. The fine seeds can be germinated in the same manner as seeds of other ericaceous plants surface sown on a free-draining compost or milled sphagnum moss. Supplementary light, although not essential, does promote good growth and stocky seedlings. Cultivars or fine forms of any species should be propagated asexually. Cuttings taken in late spring or early summer and treated with rooting hormones root with good success. Some nurseries prefer to leave rooted cuttings undisturbed in rooting cells or trays in a cold frame or cold glasshouse over their first winter. These are then potted up before they resume growth the following spring. This is probably a acknowledgements Thanks to Jack Alexander, Tomasz Anisko, Timothy M Boland, David Boufford,, William Flemer III, Paul Halladin, Brian McGowan, R Wayne Mezitt, Seamus O Brien,, Brian Upchurch, Judith Warnement, Adam Wheeler and Emily Wood for their assistance and for generously sharing their knowledge. June 2011 good protocol to follow. Propagation by cuttings has met with variable success at Arboretum Wespelaar, even when the cuttings are taken from young wood. Tissue culture of Enkianthus in commercial quantities has so far been limited to E. quinqueflorus, with some success (Yang et al. 2009), and E. campanulatus Showy Lantern (Rogers 1989). Cultivation Like other ericaceous genera, Enkianthus grow best in full sun or partial shade in moist, well-drained, acidic soils. Established plants can tolerate periodic drought, although may be sunburned when fully exposed. Where soil conditions are suitable they are readily transplanted as containerized specimens or fieldgrown, balled-and-burlapped plants. In North America, E. campanulatus is the most adaptable species and is grown in much of the eastern third of the US and milder parts of the southeastern and maritime Canadian provinces. On the West Coast it is successfully grown from parts of British Columbia southward, primarily west of the Cascade Mountains, to northern California. Cultivation of any Enkianthus in the continental interior is greatly limited by low temperatures, dry climate or high soil ph. However, a few clones of E. campanulatus are hardy to USDA Zone 4 (-28 C to -34 C) as revealed by studies at the University of Maine (Cappiello & Littlefield 1994), and the existence of decades-old plants thriving at The Fells, a historic garden in central New Hampshire. Enkianthus campan ulatus is widely cultivated in Europe, growing well where the soil ph allows ericaceous genera to prosper. Enkianthus perulatus and E. cernuus are the only other species regularly cultivated in North America and Europe. The latter is not as cold hardy as E. campanulatus and is slightly less common. Despite their ornamental merits, E. deflexus, E. chinensis and E. serrulatus are less common than the previous three. Wild origin seed of E. chinensis and E. deflexus has appeared recently in the RHS Rhododendron, Camellia and Magnolia Group seed list. The remaining species are little known in cultivation, but worthy of introduction, if only for ex situ conservation and horticultural evaluation. The genus does not suffer from the serious pests and diseases that plague Rhododendron and other, more commercial, ericaceous genera. In northeast USA Enkianthus also resist grazing by white-tailed deer. Arboretum Wespelaar in Belgium has reported scale insect, especially on E. campanulatus but fortunately it is not a common problem. The future Although the Japanese have made a concerted effort to select and name variants of their native species, no concentrated breeding program exists, despite the diversity and availability of germplasm available in private and public collections. Breeding efforts should focus on imparting greater hardiness to the showier, but tender, Chinese species such as E. quinqueflorus. Selection should also focus on expanding the flower colour range to deep yellows and oranges, and selecting clones for reliable autumn colour and compact habit. Th o m a s Clark is Collections and Grounds Manager at Polly Hill Arboretum, Massachusetts Eric Hsu is a Research Associate at Polly Hill Arboretum, Massachusetts Koen Camelbeke is Director of Arboretum Wespelaar, Belgium 85