Chrysocephalum semipapposum

Chrysocephalum semipapposum, commonly known as clustered everlasting is a perennial shrub native to Australia. Clustered everlasting belongs to the family Asteraceae. C. semipapposum produces terminal flowers heads in clusters, mainly between spring and early summer with silver-grey appearing stems and branches. It grows up to 40cm high and 60 cm high, although there have been some varieties which can grow up to 1 m. C. semipapposum is often confused as Chrysocephalum apiculatum or 'yellow buttons', due to their similar appearances. C. semipapposum has 4 different subspecies, however they lack distinctive qualities and are often hard to identify. C. semipapposum is endemic to Australia and can be found in multiple states, most notably within Victoria. The plant is found in a variety of habitats including dry rocky regions. 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.
Description.
Chrysocephalum semipapposum is a perennial herbaceous shrub, which is highly variable. Generally, the erect shrub is 15-60 cm high, and is sprawling in nature, with its width up to 40cm. Despite this general 60cm height cap, there have been forms of Chrysocephalum semipapposum found up to 1 metre tall.
Chrysocephalum semipapposum can be sometimes mistaken for a weed.
Morphology.
Inflorescence.
The floral display of the Chrysocephalum semipapposum is a corymb, or a cluster of flowers that form a flat head and can be up to 10 cm in diameter. The corymb of the Chrysocephalum semipapposum contains 70 capitula, or flowering shoots which gives the appearance of a single flower. The colour of the capitula can occur from a lemon shade to a common orange shade, or a cluster of flowers that form a flat head. These flower heads are compact clusters and are surrounded by bracts, an adapted leaf which surrounds the flower with a woolly grey appearance. 
Stems.
These corymbs are found on leafy branches, which give a silver-grey appearance. This appearance is due to silky glandular hairs which covers the stems and foliage of the Chrysocephalum semipapposum. The slender and erect stems grow from the base of the plant. The leaves are linear in shape and are 0.2-5cm long and 1-2mm wide. The leaves decrease in size towards the tip of the stem and can end in a sharp or a long, drawn-out point. The leaves are flat and are denser towards to bottom of the plant.
The upright stems grow from the base of the plant.
Fruit.
Chrysocephalum semipapposum produces a fruit – achene - which does not have to open to bear its seeds. This fruit is found within the dried-out flower heads, and many fruits grow within each flower head. The fruits have pappus bristles, which appear as a feathery attachment. The fruit is white and yellow.
Chrysocephalum semipapposum has both bisexual and female flowers
Chrysocephalum apiculatum is similar in appearance to the Chrysocephalum semipapposum. The common names of these plants are often used interchangeably in both professional and recreational settings. The inflorescence, or flower, of the Chrysocephalum semipapposum is similar in physical appearance to Chrysocephalum apiculatum which causes confusion when identifying the plant. However, Chrysocephalum apiculatum is a taller plant and has the possibility to be single stemmed or multistemmed, where Chrysocephalum semipapposum is only multi-stemmed. C. apiculatum may also have a loose to compact flowerhead, where C. semipapposum has compact flowerhead.
Taxonomy.
C. semipapposum is a part of the Asteraceae family, commonly known as daisies, under the Chysocephalum genus. The word chrysocephalum derives from Greek origins. Chryso translates to golden, and cephalus translates to headed, referring to the appearance of the compact flowers. 
Chrysocephalum semipapposum is formerly known as Helichrysum semipapposum. However, the Helichrysum genus has been reassessed to apply to African and Eurasian plants, and similar Australian plants have been reclassified to the Chrysocephalum genus.
Variation.
C. semipapposum has 4 subspecies. 
These subspecies are determined by both morphological features or physical attributes and location in which these varieties are found. C. semipapposum has historically been taxonomically difficult 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.
Subspecies.
Lineare.
This variety grows up to 80 cm high, with slender stems and narrow leaves. 
This subspecies is found in southern Eastern New South Wales, South Australia, Victoria and Tasmania.
Occurs in numerous habitats.
Growth cycle: December to February.
Brevifolium.
Brevifolium subspecies grows up to 50cm high. It has slender sparsely cottony stems with thick leaves 2-3cm long at the top of the plant and 2-6cm long at the base of the plant.
This subspecies is found in eastern New South Wales, central and south-eastern South Australia, and central and eastern Victoria.
Asperum.
C. Semipapposum subsp. Asperum grows up to 90 cm high. The stems have minimal hair, and the leaves grow up to 7cm long.
This subspecies occurs in eastern New South Wales, eastern Victoria, south-east Queensland and north-eastern Tasmania.
Occidentale.
This subspecies has been found to grow from 40-120 cm high with slender erect stems and cottony leaves which are scattered along the stems.
This subspecies is found in south-western Western Australia.
Distribution and habitat.
C. semipapposum is a native shrub to Australia. C. semipapposum varieties have been found in most Australian states, including New South Wales, South Australia, Queensland and Tasmania however C. semipapposum has been most notably found within Victoria.
C. semipapposum occurs in a variety of habitats including woodland hills, grassland hills, mountains or isolated rocky rises. They are rarely found in large groups and are most commonly found as scattered individual shrubs.
C. semipapposum can grow in a variety of soils and is a tough plant which can withstand drought.
Ecology.
C. semipapposum’s flowering season occurs from September until December, mainly throughout spring and summer. C. semipapposum is a tough shrub and natural disturbances, such as fires promote growth and flowering.
The nectar produced by the clustered everlasting flowers are a source of food for butterflies and the plant itself is minimally used as a food option for grazing animals. The plant will only be eaten when there are limited food sources available.
C. semipapposum’s growth may be impacted by lower light, producing leggy growth. The growth can also be impacted by the invasion of non-native plants.
C. semipapposum was found to inhibit the process of nitrification in the rhizosphere soil, the soil surrounding the plants roots, when compared to non-rhizosphere soil. Nitrification transforms relatively soil bound ammonium into nitrate which is more mobile and can get lost in the environment. Nitrification can cause negative impacts on the environment including toxic algae blooms, biodiversity loss and can contribute to greenhouse gas emissions and loose up to 50% of nitrogen for the plant. This compound is very important in the creation of plant proteins and stimulating growth within the plant. The rhizosphere has a great impact to the plants ability to take in nutrients, which is integral to the health and growth of the plant. 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. Further research is needed to evaluate the exact mechanisms found in C. semipapposum which contribute to the inhibition of nitrification.
Uses.
The clustered everlasting is a tough plant which can be used as ground covering in a residential garden and can help keep weeds out. It is easy to care for due to its drought tolerance and frost resistance. Growing conditions include part shade to full sun, and a dry or well-drained soil. If dried out, regular pruning down to the base of the stem can promote growth in the next season.
The seed viability for C. semipapposum is higher or equal to 80%, and can also be easily propagated. Germination can occur under both light, part shade and dark conditions. However lower light availability may produce thin and underdeveloped seedlings and leggy growth. 
Clustered everlasting can also be used as a cut flower in floral arrangements. Clustered everlasting has a vase life of 7-14 days making it ideal as a flower filler.