Zieria granulata

Location & distribution maps

Common name:         Illawarra Zieria

Conservation status: Endangered

• Zieria granulata is classified as "Endangered" under the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act

• The main threat to its survival is loss of habitat due to land clearing, quarrying, residential development and road construction

Etymology:   

• The name Zieria honours "John Zier, a Polish botanist, who assisted F.C. Ehrhart in his collection of plants of the Electorate of Hanover, 1780-83, and afterwards worked in London, where he died in 1793"

• The specific epithet (granulata) is derived from the Latin word granum meaning "grain"

Flowers

• The flowers are white and are arranged in groups of up to 180 flowers in leaf axils, each flower 3.5–7 mm in diameter

• The groups are shorter than the leaves and the flowers have four glabrous sepal lobes less than 1 mm (0.04 in) long

• The four petals are 1.5–2.5 mm long and in common with other zierias, there are only four stamens. 

• Flowering occurs during spring and summer 

Fruit:                            

• A  dry, light brown capsule containing dark, reddish seeds about 2 mm which have an ant-attracting elaiosome

Leaves:         

• Its leaves are composed of three more or less linear leaflets, with the middle leaflet 15–40 mm long and about 1 mm wide with the other leaflets smaller

• The edges of the leaflets have small teeth and are curved downwards

• The upper surfaces are dull green, hairy at first while the lower surface in whitish and covered with soft hairs

• Both surfaces are covered with tubercles

• The leaf stalk is 3–10 mm long

Stem & branches: 

• The branches are covered with warty tubercles and the youngest branches are covered with short, silky hairs

Roots:         

Habit:        

• Zieria granulata is bushy, aromatic shrub which grows to a height of about 3 m or as high as 6 m in ideal conditions

Habitat:   

• This zieria usually grows on rocky outcrops in shallow volcanic soils

Distribution:                  

• It is only found in the Shoalhaven and Kiama districts on the south coast of NSW

Additional notes:     

• Taxonomy and naming

  • Zieria granulata was first formally described in 1863 by George Bentham in Flora Australiensis, following a description by Charles Moore which had not been validly published

• Use in horticulture

  • Illawarra zieria is well known in cultivation and is hardy in well-drained soil

  • It prefers semi-shaded positions but will grow in full sun, is drought hardy and moderately frost hardy

  • Light pruning is recommended to maintain a bushy shape

Sources of information:

• https://en.wikipedia.org/wiki/Zieria_granulata (2024)