Narrow-leafed Drumstick

Appearance

"Isopogon anethifolius" is a shrub usually between 1 and 3 m high with an upright habit. It generally grows taller in more sheltered areas such as woodlands, and shorter in more exposed areas. The stems are reddish in colour, and new growth in winter is tinged with reddish and tan tones.

The leaves are terete and less than 1 mm in diameter. They branch once or twice in their 16 cm length. The globular yellow flowerheads, known as inflorescences, appear at the ends of branches in spring and early summer, though occasionally at other times of year. These are up to 4 cm in diameter. The individual flowers arise out of the central woody globe in a spiral pattern, and are around 1.2 cm long.

They are straight stalkless structures that originate from a scale on the globe, composed of a tubular structure known as the perianth, which envelopes the flower's sexual organs. The perianth splits into four segments, revealing a thin delicate style tipped with the stigma. At the ends of the four perianth segments are the male pollen-bearing structures known as anthers. Arranged in a spiral pattern, the flowers open from the outer/bottom of the flowerhead inwards. The egg-shaped grey cones are revealed as the old flower parts fall away, and are up to 2.5 cm in diameter. The seed-bearing nuts are small—up to 4 mm across—and lined with hairs. The seed weighs around 4 mg.

The terete leaves readily distinguish "Isopogon anethifolius" from other members of the genus, which have flat leaves and are greater than 1 mm across. On a microscopic level, the supporting ground tissue of "I. anethifolius" differs from some of its genus by its irregular misshapen sclereids and contorted cell body.

Distribution

"Isopogon anethifolius" is found only in New South Wales, where it occurs in the Sydney Basin and surrounds, from Braidwood northwards to Mount Coricudgy in Wollemi National Park. The annual rainfall in these areas ranges from 900 to 1600 mm.

Habitat

The species occurs naturally from sea level to 1200 m altitude and is found on sandstone in heathland and dry sclerophyll woodland. Typical trees it is associated with include the scribbly gums "Eucalyptus haemastoma" and "E. sclerophylla" and silvertop ash, open forest plants such as soft geebung, and heathland plants such as heath banksia, dwarf she-oak and Wingello grevillea.