Pale bridewort	Status LU: established. 1st record: LU 1823, ITW 1949.
	Wäisse Kluddertrausch	Status Eur.: established. 1st record: ?
	Spirée blanche	RA: ISEIA: C1. Harmonia+: 0,16.
	Weißer Spierstrauch	Wikipedia: | Wikispecies:
	Witte spirea	Back to the list of neophytes

Report the species

→ Report Spiraea alba to the National Museum of Natural History.

Brief description

Spiraea alba Du Roi is a shrub that prefers moist to wet conditions and grows on soil with abundant nutrients and organic material. It occurs mainly in riparian habitats such as river banks, wet meadows, swamps, ditches and bogs. This pioneer species needs full sunlight for optimal growth, flowering and fruiting, but may survive under the tree canopy. It reproduces mainly vegetatively and may be propagated via garden waste or waterflow.

The Pale Bridewort is a fast-growing rhizomatous species, propagating clonally. It forms stable and very dense shrub communities that can expand over large areas and displace native plant species. The dense cover of this plant prevents tree regeneration and inhibits the successional process towards a forest stage. This species is locally considered a weed in its native range. Old dry plant shoots are vulnerable to early ignition and may be the cause of fires (Branquart et al. 2010).

Status and distribution in Luxembourg

Spiraea alba Du Roi was first mentioned for Luxembourg as introduced under its synonym S. undulata in 1823 in the park of Schrassig (Koltz 1875: 67).

The oldest MNHNL herbarium specimen of its variety Spiraea alba var. latifolia (Aiton) Dippel was collected under the synonym Spiraea latifolia (Aiton) Borkh. by Jos Witry on 26 July 1935 in Dalheim (Specimen № 52327, MNHNL 2000-).

The first documented record in the wild was reported on 1949-08-05 at Osterbour, naturalised by a pond, in the municipality of Larochette (Beck et al. 1952: 77; MNHNL 2000-).

Currently, 7 records of the Pale Bridewort are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

This species originates from the eastern United States and is sometimes cultivated for ornamental purposes in parks. Subspontaneous or naturalised; banks of rivers and ponds, hedges (Lambinon & Verloove 2012: 326).

This species seems to have sometimes been confused in the wild with the horticultural hybrid Spiraea ×rosalba Dippel (Spiraea alba × salicifolia), with petals generally of a brighter pink, with shorter branches and stamens longer than petals (about as long as the latter in S. alba). The frequency and distribution of the two taxa should be studied in the wild, the degree of pollen fertility being perhaps a useful criterion for distinguishing them (Lambinon & Verloove 2012: 326).

Risk assessment

ISEIA protocol

C1 (1+1+3+2) (Ries et al. 2013: 19).

Harmonia+ protocol

Overall risk score 0,16 = (Overall Invasion score 0,34 x Overall Impact score 0,47) (Ries et al. 2020).

Worldwide distribution

Bibliography

• Beck, E., Jungblut, F., Lefort, F.L., Reichling, L., Stumper, R., 1952. Herborisations faites au Grand-Duché de Luxembourg en 1951. Bull. Soc. Nat. luxemb. 56: 67-88. [PDF 1080 KB]
• Branquart, E., S. Vanderhoeven, W. Van Landuyt, F. Van Rossum & F. Verloove, 2010. Harmonia database: Spiraea alba Du Roi. Harmonia version 1.2, Belgian Forum on Invasive Species. URL: http://ias.biodiversity.be [accessed on 2019-10-15]
• GBIF, 2020. Spiraea alba Du Roi in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei [accessed 2020-03-04]
• Koltz, J.-P.-J., 1875. Dendrologie luxembourgeoise. Catalogue des arbres, arbrisseaux et arbustes spontanés, subspontanés ou introduits dans la culture du Grand-Duché de Luxembourg. Imprimerie V. Buck, Luxembourg, 217 pp.
• 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 alba Du Roi 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 alba Du Roi 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, 2021. First records of 56 invasive alien vascular plants in Luxembourg. Bulletin de la Société des naturalistes luxembourgeois 123: 115-127. [PDF 241 KB]
• Ries, C., Y. Krippel & M. Pfeiffenschneider, 2020. Risk assessment after the Harmonia+ protocol of invasive alien vascular plant species in Luxembourg. Bull. Soc. Nat. luxemb. 122: 197-205. [PDF 132 KB]
• 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]