Helichrysum waitzioides (Diels) Domin Chrysocephalum semipapposum, commonly known as clustered everlasting is a perennial shrub native to Australia.

[2][3][4] C. semipapposum produces terminal flowers heads in clusters, mainly between spring and early summer[4] with silver-grey appearing stems and branches.

C. semipapposum is endemic to Australia and can be found in multiple states, most notably within Victoria.

[4] Clustered everlasting often grows sparsely and is rarely found in abundance and can be mistaken for a weed.

Clustered everlasting has many uses, including as a source of nectar for butterflies, cut flowers or as an addition to a garden.

[5] Despite this general 60 cm height cap, there have been forms of Chrysocephalum semipapposum found up to 1 metre tall.

[6] The floral display of the Chrysocephalum semipapposum is a corymb,[7] or a cluster of flowers that form a flat head[8] and can be up to 10 cm in diameter.

[7] This appearance is due to silky glandular hairs which covers the stems and foliage of Chrysocephalum semipapposum.

[4] The leaves decrease in size towards the tip of the stem[7] and can end in a sharp or a long, drawn-out point.

[12] Chrysocephalum semipapposum produces a fruit or achene which does not have to open to bear its seeds.

[20] The plants may be annual or perennial[20][21] and the flower heads contain complicated inflorescence which are surrounded by bracts.

[24] A polyphyletic genus refers to a group of organisms which are derived from more than one ancestor and are not suitable to be placed in the same taxon.

[25] The Helichrysum genus has been reassessed by botanist Arne Anderberg to apply to African and Eurasian plants.

[11][19][27] These subspecies are determined by both morphological features or physical attributes and location in which these varieties are found.

[11] C. semipapposum has historically been taxonomically difficult[19] and the subspecies have similar variations which cause overlap.

Because of these similar attributes, the subspecies are broad based and do not have specific infraspecific or scientific names.

[11] This variety grows up to 80 cm high, with slender stems and narrow or linear leaves.

[6] The flowering season of C. semipapposum occurs from September until December, mainly throughout spring and summer.

[7][12][19] C. semipapposum is a tough shrub[33] and natural disturbances, such as fires promote growth and flowering.

[12] Chrysocephalum semipapposum will only be eaten as a last resort, when there are limited food sources available.

[5] Chrysocephalum semipapposum was found to inhibit the process of nitrification in the rhizosphere, when compared to non-rhizosphere soil.

[36] Nitrification is the process which transforms the compound ammonium, which is relatively soil bound, into nitrate.

[38] High levels of nitrogen in the environment can cause toxic algae blooms, biodiversity loss and can contribute to greenhouse gas emissions.

[36][35] The ability of C. semipapposum to inhibit the process of nitrification is closely related to the lower amount of ammonia oxidising bacteria (AOB) found in the rhizosphere.

[35] Further research is needed to evaluate the exact mechanisms found in C. semipapposum which contribute to the inhibition of nitrification.

[6][12] Growing conditions include part shade to full sun, and a dry or well-drained soil.

[12] Propagation can occur through taking cuttings of a pre-existing plant and placing them within a mist bed.

[5] However, lower light availability may produce thin and underdeveloped seedlings and leggy growth.

[7] Clustered everlasting has a vase life of 7–14 days[7] making it ideal as a flower filler.