Cotinus coggygria × obovatus
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Credits
Owen Johnson (2025)
Recommended citation
Johnson, O. (2025), 'Cotinus coggygria × obovatus' from the website Trees and Shrubs Online (treesandshrubsonline.
Synonyms
- Cotinus × dummeri nom. inval.
- 'Dummer Hybrids' in part
Infraspecifics
Artificial and accidental hybrids between Cotinus coggygria and C. obovatus, intermediate in appearance, e.g. arborescent if not coppiced, with leaves larger than ordinary for C. coggygria but smaller than ordinary for C. obovatus, not so tapered at the base as in C. obovatus but more pubescent underneath than in the common European forms of C. coggygria (Edwards & Marshall 2019; Clarke 1988).
Habitat In gardens only.
USDA Hardiness Zone 4
RHS Hardiness Rating H6
Hybrids between European and American Smokebushes are sometimes referred to as Cotinus × dummeri, or the Dummer Hybrids, commemorating Peter Dummer, a propagator at the Hillier Nurseries who experimentally crossed the two species in 1978 (Dirr 2009), as discused under the entry for ‘Grace’. But this name has not been validly published, and Dummer was not the first nurseryman to raise such hybrids; the Cotinus now known as ‘Flame’ seems to have arisen at Léon Chenault’s nursery at Orléans in France around the turn of the 19th and 20th centuries, and has been sold as a selection of both species, but shows hybrid features (Edwards & Marshall 2019). The six or so known first-generation hybrids are grouped together here for convenience, but are conventionally treated as standalone cultivars (e.g. Cotinus ‘Grace’).
'Candy Floss'
Synonyms / alternative names
Cotinus 'Candyfloss'
In the late 1990s Alan Postill, a propagator at the Hillier Nurseries in Hampshire, UK, experimentally hybridised Cotinus coggygria ‘Daydream’ with C. ‘Grace’, a hybrid of C. coggygria with C. obovatus which had been raised by Peter Dummer at the same nursery in 1978 (D. Jewell pers. comm. 2024; Edwards & Marshall 2019 is incorrect in stating that the hybrid parent was C. ‘Flame’). The five best hybrids were picked and named around 2003; in 2008, ‘Candy Floss’ (‘Clone 1’) was selected along with ‘Ruby Glow’ for commercial propagation, debuting in 2014 (Hobbs 2023). Its leaves open bronze, then turn green and later show a gamut of autumn colours; the large soft-pink flower- and seed-heads resemble candyfloss (Edwards & Marshall 2019).
'Elodie'
Synonyms / alternative names
Cotinus 'Elodie'
One of five hybrids between C. coggygria ‘Daydream’ and C. ‘Grace’ to be selected by Alan Postill at the Hillier Nurseries around 2003, ‘Elodie’ (‘Clone 5’) was named after Postill’s granddaughter (D. Jewell pers. comm. 2024). ‘Elodie’ was never sold commercially, but at the Sir Harold Hillier Gardens has made a bush 4.7 m tall, with good purple foliage (Tree Register 2024).
'Flame'
Synonyms / alternative names
Cotinus americanus 'Chenault's Variety'
Cotinus coggygria 'Flame'
Cotinus 'Flame'
The plant now known as Cotinus ‘Flame’ was originally sold as C. americanus (syn. C. obovatus) ‘Chenault’s Variety’, implying that it was raised by Léon Chenault (1853–1930) at his nursery in Orléans, France. By the later 20th century it was treated as a cultivar of C. coggygria (e.g. by Bean (1976)) but in the 1980s Allen Coombes, then based at the Sir Harold Hillier Gardens, made the case that it is of hybrid origin: its leaves are rather larger and hairier underneath than is normal for cultivated C. coggygria, and its principle selling point – the brilliant orange-red of its autumn colour show – is characteristic of the American tree (Clarke 1988; Edwards & Marshall 2019). Its flower- and seed-heads are large and pink.
‘Flame’ makes a slightly less vigorous plant than the comparable hybrid Cotinus ‘Grace’; in the Autumn Garden at the Cambridge University Botanic Garden, UK, where the alkaline soil and rather continental climate suit Smokebushes well, a bush was 5 m tall with a very short trunk 24 cm thick at 40 cm in 2014 (Tree Register 2024). This seems to be the oldest Smokebush selection to remain widely available.
'Grace'
Synonyms / alternative names
Cotinus 'Grace'
In 1978 Peter Dummer, a propagator at the Hillier Nurseries in Hampshire, UK, used pollen from Cotinus obovatus to pollinate the purple-leaved C. coggygria cultivar ‘Velvet Cloak’; he scarified the seeds with acid and they germinated within twelve days (Dirr 2009; Edwards & Marshall 2019). Five clones were selected, with ‘Clone 2’ being launched commercially in 1984 as C. ‘Grace’ (Jacobson 1996); Dummer named this plant after his wife (not his daughter as reported in Clarke 1988; D. Jewell pers. comm. 2024).
‘Grace’ has gained a reputation as one of the most attractive Cotinus; indeed, the great American horticultural taxonomist Laurence Hatch says that, if he only had room for one Smokebush, this would be it (Hatch 2024). The leaves, which are slightly larger than those of typical C. coggygria, flush a vibrant red-purple and fade slowly towards a subtle, dark blue-green; their scarlet autumn colour has the depth and richness of the American parent; the flower- and seed-heads are huge and deep pink. The plant shows hybrid vigour, and some of the oldest are already as large as the oldest C. coggygria; one by the Lily Pond at Kew Gardens was 8 m tall with a main trunk 32 cm thick at 1 m in 2022, and another in woodland at one of the late Maurice Mason’s Norfolk gardens was marginally taller in 2019 (Tree Register 2024). ‘Grace’ is also adaptable enough to thrive in the Australian National Arboretum at Canberra (Australian National Arboretum Canberra 2024).
Dummer also back-crossed ‘Grace’ with Cotinus obovatus in search of even richer autumn colour, and this cross, along with Dummer’s clones 1, 4 and 5, is still represented at the Sir Harold Hillier Gardens (Royal Botanic Garden Edinburgh 2024).
'Jenni'
Synonyms / alternative names
Cotinus 'Jenni'
Among the hybrid clones selected by Alan Postill at the Hillier Nurseries around 2003 as hybrids of Cotinus coggygria ‘Daydream’ with C. ‘Grace’, ‘Jenni’ (‘Clone 2’) was named after Jenni Hobbs, a nursery staff member (D. Jewell pers. comm. 2024). Although ‘Jenni’ was never commercially distributed, the clone is still represented at the Sir Harold Hillier Gardens (Royal Botanic Garden Edinburgh 2024). Red young leaves quickly fade to bronzy-green.
'Ruby Glow'
Synonyms / alternative names
Cotinus 'Ruby Glow'
Among the five hybrid seedlings of Cotinus coggygria ‘Daydream’ × C. ‘Grace’ selected by Alan Postill at the Hillier Nurseries around 2003, ‘Ruby Glow’ (‘Clone 4’) was chosen for commercial release in 2008 and launched in 2014 (Hobbs 2023; D. Jewell pers. comm. 2024; Edwards & Marshall 2019 is incorrect in stating that the hybrid parent was C. ‘Flame’). ‘Ruby Glow’ makes a more compact shrub than its sister-seedling ‘Candyfloss’; its dark green leaves flush bronze and retain a reddish tint, and its pink flower- and seed-heads almost hide the foliage from midsummer on (Edwards & Marshall 2019; Royal Horticultural Society 2024).
'Wendy'
Synonyms / alternative names
Cotinus 'Wendy'
‘Wendy’ (‘Clone 3’) was one of five seedlings selected by Alan Postill at the Hillier Nurseries around 2003 from an experimental cross of Cotinus coggygria ‘Daydream’ with C. ‘Grace’; the plant was named after the partner of David Jewell, now Curator of the Sir Harold Hillier Gardens (D. Jewell pers. comm. 2024). Although never commercially distributed, C. ‘Wendy’ is still represented in the Gardens’ unrivalled Cotinus collection (Royal Botanic Garden Edinburgh 2024).