Origin of name:
argentissimum = very silvery
Linear woolly leaves
Large solitary heads
Mat-forming perennial herb with numerous crowded leaf rosettes arising from a thick, woody, well-branched underground stem system, flowering stems terminal, solitary, up to 400 mm long, but often less than 150 mm, grey-woolly, leafy. Radical leaves up to 120 x 6 mm, but often only 30�50 x 3�4 mm, linear or linear-lanceolate, apex acute to subacute, silvery grey silky-woolly; cauline leaves similar but shorter, uppermost with a white scarious tip. Heads homogamous or heterogamous, campanulate, c. 20 mm long, double that across the fully radiating bracts, solitary. Involucral bracts in c. 10 series, graded, loosely imbricate, much exceeding the flowers, acute, glossy white, crimson or pink blotch at base inside. Receptacle shortly honeycombed. Flowers 111�201, 0�10 female, 103�191 homogamous. Achenes 1,5 mm long, barrel-shaped, with myxogenic duplex hairs. Pappus bristles many, tips barbellate, bases cohering by patent cilia, some fusion in bundles as well.
Flowers between September and March, but mainly in spring.
Grows on stony grass slopes or on broken sandstone cliffs or platforms, forming thick mats as much as a meter across where protected from fire. Ranges from Bergville, Estcourt, Lion's River, Umvoti and New Hanover districts south to Mt Currie in East Griqualand and Insizwa and Tabankulu Mountains in the Eastern Cape, between c. 900 and 2 300 m above sea level.
Closely resembles H. lingulatum, but is distinguished by its linear, not lingulate, leaves and silky-woolly, not merely woolly, indumentum. Possibly hybridizes with other species; see under H. ecklonis.
Helichrysum argentissimum J. M. Wood in Kew Bull. 1907: 364 (1907); Hilliard, Compositae in Natal 237 (1977).
KwaZulu-Natal, Lion's River distr., summit Mt Gilboa, Wylie in herbarium Wood 10025 (NH, holo.; BOL; E; K; PRE; S; SAM, iso.).
Hilliard & Burtt 7319 (E; K; NU; S); Strey 10533 (NU); Wright 208 (E; K; NH; NU).