Buddleja × weyeriana

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Lamiales

Familia: Scrophulariaceae
Tribus: Buddlejeae
Genus: Buddleja
Sectio: B. sect. Buddleja
Nothospecies: Buddleja × weyeriana
Name

Buddleja × weyeriana Weyer ex Rehder (1927)

Formula hybridae: Buddleja davidii Franch. × Buddleja globosa Hope

References

Rehder, A. 1927: Manual of cultivated trees and shrubs hardy in North America 769.

Buddleja × weyeriana is one of the more remarkable Buddleja hybrids, the first crossing of an Asiatic species (B. davidii) with a South American (B. globosa). The hybrid was raised during the First World War by the eponymous Major William van de Weyer at his home, Smedmore House, at Corfe Castle, England. Van de Weyer was hoping to achieve an inflorescence the size of davidii with the colour of globosa, but met with only limited success.[1][2][3]

Description

The F1 progeny of × weyeriana was a disappointment, the inflorescences small and the colours drab. Van de Weyer rightly deduced the colour was a function of a recessive trait, and reputedly crossed the F1 plants to raise the superior F2 cultivars 'Golden Glow' and 'Moonlight', although both retained vestiges of the lilac colouring of davidii. However, Moore considered it more likely the cultivars arose from backcrossing the F1 hybrids with B. globosa.[4] The shrub's nectar is relatively complex, comprising three constituents in almost equal proportions: sucrose, fructose, and glucose, whereas the nectar of the common Buddleja davidii is almost exclusively sucrose.[5]

It was not until half a century later that the colour objective was realized, when a Dutch nursery cloned a pure orange-yellow sport of 'Golden Glow' to produce 'Sungold'.[2] An inflorescence the size of davidii with this desired colour remains (2014) elusive. Ploidy: 2n = 76.[6]
Cultivation

Buddleja × weyeriana 'Golden Glow' is the original plant of van de Weyer[1] exhibited in 1920. A specimen is grown as part of the NCCPG national collection held by the Longstock Park Nursery.[7] together with the cultvars 'Sungold', 'Moonlight', and Buddleja × weyeriana 'Variegata'. The authenticity of the other cultivars remains a matter of contention.
Cultivars

At least nine cultivars have been raised, nearly all in Europe:

Buddleja × weyeriana 'Elstead Hybrid'
Buddleja × weyeriana 'Flight's Fancy' (syn. 'Variegata')
Buddleja × weyeriana 'Golden Glow'

Buddleja × weyeriana 'Golden Tassles'
Buddleja × weyeriana 'Honeycomb'
Buddleja × weyeriana 'Lady de Ramsey'

Buddleja x weyeriana 'Moonlight',
Buddleja × weyeriana 'Sungold'
Buddleja × weyeriana 'Trewithen'

References

Weyer, van de, W. (1920) Buddleja weyeriana. Gardeners' Chronicle ser. 3, 68: 181. 1920.
Bean, W. J. (1980). Trees and shrubs hardy in the British Isles. Vol.1. 8th edition. Murray, UK.
Stuart, D. (2006). Buddlejas. RHS Plant Collector Guide. Timber Press, Oregon. ISBN 978-0-88192-688-0
Moore, R. J. (1960). Cytotaxonomic notes on Buddleia. L. Am. J. Bot. 47, 6, p. 511-517. 1960.
Percival, M. (1961). Types of nectar in angiosperms. New Phytol. 60: 235-281. 1965. Floral biology. Pergamon Press, London.
Norman, E. M. (2000). Buddlejaceae. Flora Neotropica 81. New York Botanical Garden, USA
Moore, P. (2012). Buddleja List 2011-2012 Longstock Park Nursery. Longstock Park Nursery, UK.