Alyssum L.

(excl. Aurinia)

Alyssum is a complex genus in which generic boundaries have long been obscure (see Akeroyd 1995, Mabberley 2008). As currently understood (excluding for instance Aurinia) Alyssum still counts ca. 170-190 species, mainly native to the Mediterranean area and Eurasia (+ one additional species in North America). It has been further split into nine or more segregates but these are poorly understood and pending thorough molecular studies the genus is better broadly circumscribed (Al-Shehbaz 2010). The incongruence between morphology and molecular data indicates that the current taxonomic circumscription of the genus and sections need to be revised (Li & al. 2015). Only one species is native in Belgium: Alyssum alyssoides (L.) L. It is much decreasing in the past decades and even extinct in Flanders since 1974 (Van Landuyt 2006). About 20 species are cultivated as ornamentals in Europe (Akeroyd 1995) but only few of these are rather regularly seen in gardens in Belgium.

1. Plant annual or biennial. Petals pale yellow, turning whitish (native) === Alyssum alyssoides

1. Plant perennial. Petals pure yellow === 2

2. Inflorescence a raceme (elongate in fruit). Leaves more or less concolourous. Petals emarginate at apex. Two seeds per loculus === 1. Alyssum montanum

2. Inflorescence corymbose. Leaves distinctly discolourous (lower side whitish hairy). Petals entire at apex. One seed per loculus === 2. A. murale

Additional aliens: Alyssum desertorum Stapf (E and SE-Eur., wool alien), A. hirsutum Bieb. (SE-Eur., grain alien?), A. simplex Rudolphi (syn.: A. minus Rothm.) (S and E-Eur., wool and grain alien) and A. strigosum Banks et Sol. (SE-Eur., grain alien?).



Akeroyd J.R. (1995) Alyssum. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 146-148.

Al-Shehbaz I.A. (2010) Alyssum. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 7. Oxford University Press, New York-Oxford: 247-251.

Ball P.W. & Dudley T.R. (1993) Alyssum. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 1. (2nd ed.). Cambridge University Press, Cambridge: 359-369.

Dudley T.R. (1964a) Synopsis of the Alyssum. J. Arnold Arbor. 45: 358-373.

Dudley T.R. (1964b) Studies in Alyssum: Near Eastern representatives and their allies, I. J. Arnold Arbor. 45: 57-100.

Dudley T.R. (1965) Studies in Alyssum: Near Eastern representatives and their allies, II. Section Meniocus and section Psilonema. J. Arnold Arbor. 46: 181-217.

Dudley T.R. (1966) Ornamental madworts (Alyssum) and the correct name of the goldentuft alyssum. Arnoldia 26: 33-48.

Dudley T.R. (1968) Alyssum (Cruciferae) introduced in North America. Rhodora 70: 298-300.

Lambinon J., Delvosalle L., Duvigneaud J. (avec coll. Geerinck D., Lebeau J., Schumacker R. & Vannerom H.) (2004) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Cinquième édition. Jardin botanique national de Belgique, Meise: CXXX + 1167 p.

Li Y., Feng Y., Lv G., Liu B. & Qi A. (2015) The phylogeny of Alyssum (Brassicaceae) inferred from molecular data. Nordic Journal of Botany 33: 715-721. [available online at:]

Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.

Van Landuyt W. (2006) Alyssum alyssoides. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 129.

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith