Helichrysum

Helichrysum Mill.

As currently understood (Mabberley 2008) Helichrysum still is a very heteromorphous genus of ca. 500-600 species (Galbany-Casals & al. div. publ.). It is originally confined to the Old World and its center of diversity possibly is in South Africa. Its generic boundaries have considerably changed in the past decades. Several species (including those from Australia) are now accommodated in segregate genera (for instance Xerochrysum to which the popular annual strawflower X. bracteatum (Vent.) Tzvelev now belongs). One species, Helichrysum arenarium (L.) Moench, is a very rare and local, nearly extinct native in Belgium (Lambinon & al. 2004). Several species of Helichrysum are cultivated as ornamentals (see Brown 2000 and Jäger & al. 2008 for recent accounts for Europe).

1. Leaves almost circular with a distinct petiole. Flower heads creamy-white. Stem eventually trailing === 2. Helichrysum petiolare

1. Leaves narrowly linear without distinct petiole. Flower heads yellow. Stem never trailing === 2

2. Aromatic (strong smell of curry), shrubby perennial (becoming woody at base). Involucre 2-4 mm across. Leaves usually greenish, glabrescent and only sparsely tomentose when young === 1. H. italicum

2. Inodorous, herbaceous perennial. Involucre 4-5 mm across. Leaves usually densely white-tomentose (native) === H. arenarium


Literature:

Brown N. (2000) Helichrysum. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 560-562.

Clapham A.R. (1976) Helichrysum. In: Tutin T.G. & al. (eds.), Flora Europaea, vol. 4. Cambridge University Press, Cambridge: 128-131.

Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.

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.

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

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