Pycnosorus globosus

Pycnosorus globosus, Billy Buttons, is a dense soft-wooded ground cover with a spread of at least 50 cm, with flowering stems to 120 cm tall. This species appears somehwat similar to the related Chrysocephalum apiculatum.

It has a widespread natural distribution, growing only in the inland areas of NSW, on the western slopes to the far western plain, and over most of this terrain – west of areas such as Albury, Tamworth and Glen Innes; right out to the north-west of the state; much less found in the south-west. It extends into Victoria, where it grows between Wodonga and Mathoura and south-west to Horshame and Bendigo. It extends into Queensland, growing between Warwick-Toowoomba and areas near Cunnamulla and north to near Mitchell. It is found in South Australia between Port August and Adelaide (north of Adelaide) and further north past Hawker. There are some additional small-patch disjunct records in the middle of South Australia and along the South Australia / Queensland border.

It is found often in dry sclerophyll woodland and open shrubby and grassland patches – often in moist depressions on sandy-clay soils. It is often seen on vegetated road verges.

Pycnosorus spp. have simple basal and flowering-stem (cauline) leaves, arranged alternately. In this species, basal leaves do not persist long; both basal and cauline leaves are linear, to 30 cm long (often much shorter), by 1.2 cm wide, with prominent longitudinal veins, white-grey in colour due to dense hairs; with an overall soft texture.

Pycnosorus spp. are in the daisy family and therefore produce flowers in an inflorescence called a capitulum (often referred to as a ‘head’). This is an evolved structure where a large number of modified flowers (florets) are grouped together to look like one flower. The Sunflower (*Helianthus annuus) would be the most grandiose example. The ‘petals’ of the capitula are actually ‘ray florets’ which contain a floret hidden inside the elongated ‘petal’ which is actually an extended limb of the corolla tube called a ligule. The disc in the middle of the capitulum (often yellow or orange in colour) consists of very small ‘disc florets’ which have a small 3-5 lobed corolla tube with stamens and a carpel. A frequent associated part of any capitulum is an involucre (overlapping rows) of bracts which typically subtend and surround the floral parts.

In this genus, ray florets are bascially absent – only disc florets form the head (which can be the case in many daisy-genera), which are surrounded by the involucre of papery bracts and with florets arranged as a globular head. (This genus gets very complicated in that the globose heads are thought to be a cluster of separate partial heads). In this species, the globular heads are raised solitarily on peduncles to 120 cm long, about 35 mm in diameter, consisting of many small florets, yellow to golden-yellow in colour, usually produced in spring and summer).

The fruit is an achene; with a cuneate shape to 3 mm long and 1 mm wide with a pappus of hairs/bristles to 5 mm long.