Helichrysum


The genus Helichrysum consists of an estimated 600 species of flowering plants in the sunflower family. The type species is Helichrysum orientale. The name is derived from the Greek words ἑλίσσω and χρῡσός.
It occurs in Africa, Madagascar, Australasia and Eurasia. The plants may be annuals, herbaceous perennials or shrubs, growing to a height of. The genus was a wastebasket taxon, and many of its members have been reclassified in smaller genera, most notably the Everlastings, now in the genus Xerochrysum.
Their leaves are oblong to lanceolate. They are flat and pubescent on both sides. The bristles of the pappus are scabrous, barbellate, or plumose.
The receptacle is often smooth, with a fringed margin, or honey-combed, and resemble daisies. They may be in almost all colors, except blue. There are many capitula and generally flat-topped corymbs or panicles. The corolla lobes show glandular hairs at the abaxial surface.
Helichrysum species are used as food plants by the larvae of some Lepidoptera species including the bucculaticid leaf-miners Bucculatrix gnaphaliella and Bucculatrix helichrysella and the Coleophora case-bearers C. caelebipennella, C. gnaphalii and C. helichrysiella.

Species

Hilliard divided this large and heterogeneous genus in 30 morphological groups. But this genus is controversial and is considered by many as an artificial genus. The taxonomy of the large polymorphic and probably polyphyletic genus Helichrysum is complex and not yet satisfactorily resolved. Several Australian species, such as H. acuminatum and H. bracteatum, have been reclassified in the genus Xerochrysum in 1991, resp. as X. subundulatum and X. bracteatum. In 1989, misaligned species of Helichrysum were reclassified in Syncarpha. Species included in Pseudognaphalium, Anaphalis, Achyrocline and Humeocline are probably congeneric with Helichrysum.
;Established species include:
Helichrysum stoechas is similar to the Helichrysum arenarium, but the leaves are all linear, with rolled under edges. It is found in western France on dunes near the sea.
;New species:
In 2004, A. Miller identified five potentially new species that have not yet been published but were included in the IUCN Red List data, given their restricted range in Yemen. They are as follows:
Several species are grown as ornamental plants, and for dried flowers. When cut young and dried, the open flowers and stalks preserve their colour and shape for long periods.
Helichrysum italicum is steam distilled to produce a yellow-reddish essential oil popular in fragrance for its unique scent, best described as a mixture of burnt sugar and ham. The epithet angustifolium means narrow leaved. It is commonly misspelled as augustifolium.

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