Spiraea ×billardii Hérincq

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English Billard’s bridewort ISEIA: B1 – Watch List
Lëtzebuergesch Billard-Kluddertrausch EASIN
Français Spirée de billard Wikipedia: Wikipedia - Français - Spirée de billard
Deutsch Billards Spierstrauch Wikispecies: Wikispecies - Spiraea × billardii
Nederlands Billardspirea Back to the list of neophytes

Brief description

Spiraea ×billardii Hérincq is a sterile horticultural hybrid between Spiraea alba Du Roi and Spiraea douglasii Hook. It only reproduces clonally. It grows mainly in ruderal areas and in riparian habitats. Plant habitat preferences are poorly known so far.

S. billardii is a fast-growing rhizomatous species, propagating clonally. As for other Spiraea species, it may easily form dense monospecific thickets smothering native vegetation. It is not known, however, if it has the capacity to inhibit plant successions like S. alba (Branquart et al. 2010).

Status and distribution in Luxembourg

Distribution map of Spiraea ×billardii Hérincq in Luxembourg. Data source: Recorder-Lux, iNaturalist & GBIF, 2020-01-23.

The first documented record of Spiraea ×billardii Hérincq was reported by Xavier Mestdagh on 27th June 2011, north of Consthum, municipality of Parc Hosingen (MNHNL 2000-).

Currently, 5 records of Billard’s bridewort are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

This horticultural species is often grown for ornamental purposes in parks and gardens. Subspontaneous or naturalised: old hedges, roadsides, embankments, wastelands (Lambinon & Verloove 2012: 326).

This Spiraea is by far the most widespread in the wild. However, the identity of the plant remains debatable: some authors distinguish Spiraea ×billardii (very pale pink corolla; narrowly conical inflorescence) and Spiraea ×Silverside Silverside (Spiraea douglasii × salicifolia) (bright pink corolla; subcylindrical inflorescence; leaf blade more regularly toothed, almost to the base), which would be much more common. However, the recognition of these two taxa seems difficult and therefore S. billardii is sometimes treated in a broad sense as a hybridogenic species that is more or less variable (Lambinon & Verloove 2012: 326).

Risk assessment

ISEIA protocol: B1 (2+2+3+2) = Watch List, reassessed on 24 January 2019 by C. Ries and M. Pfeiffenschneider. Original assessment: B0 (2+2+3+2) = Alert List (Ries et al. 2013: 19).


  • Branquart, E., P. Dupriez, S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Spiraea ×billardii Hérincq. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-15]
  • Lambinon J. & F. Verloove, 2012. Nouvelle flore de la Belgique, du grand-duché de Luxembourg, du Nord de la France et des régions voisines. Sixième édition. Avec la collaboration de L. Delvosalle, B. Toussaint, D. Geerinck, I. Hoste, F. Van Rossum, B. Cornier, R. Schumacker, A. Vanderpoorten et H. Vannerom. Jardin botanique national de Belgique, Meise. CXXXIX + 1195 pp. ISBN : 9789072619884.
  • MNHNL, 2000-. Spiraea ×billardii Hérincq in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-15]
  • MNHNL, iNaturalist & GBIF, 2019. Spiraea ×billardii Hérincq in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-15]
  • Ries, C., Y. Krippel, M. Pfeiffenschneider & S. Schneider, 2013. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of non-native vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 114: 15-21. [PDF 652 KB]

 Page content last updated on 2019-11-21. Last proofread by Caroline Grounds on 2019-11-21.