The genus Helichrysum consists of an estimated 600 species, in the sunflower family, Asteraceae. It occurs in Africa (with 244 species in South Africa), Madagascar, Australasia and Eurasia. The plants may be annuals, herbaceous perennials or shrubs, growing to a height of 60 to 90 cm. 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.

Helichrysum retortum, commonly known as Flask Everlasting or Sea Strawflower and synonymously known as Xeranthemum retortum, is a straggling silvery shrublet grows up to 50 cm tall, although the stems may be longer. The overlapping leaves grow close to the stem. They are oblong and the upper leaves are folded and hooked. They are covered in tissue paper-like hairs, making them a silvery colour. Papery flowers are present between August and December. The terminal disc shaped flower heads are nested in leaves and surrounded by white, glossy bracts that are brown or pink on the outside. The flowers have a diameter of about 4 cm. The ray florets are shiny white in colour and are often flushed with brown and pink. The disc florets are yellow in colour. This plant is always found growing near the sea. It is found growing on sand cliffs, sand dunes and sandy slopes and flats along the southwest coast of South Africa, from Blouberg to the north of Table Bay and Stillbaai. It sometimes grows up between neighbouring bushes.