A wide range of plant species can be found in Nillumbik - from large, long-lived trees such as Yellow Box (Eucalyptus melliodora) to tiny, delicate, short-lived herbs such as Slender Stylewort (Levenhookia sonderi).
Approximately 1325 indigenous flora species have been recorded within Nillumbik.
The distribution of these plants is determined by environmental factors such as soil type, rainfall, hydrology and topography.
Indigenous flora is essential for maintaining a healthy ecosystem and provides important habitat for our fauna.
However, a number of the plants found in Nillumbik are now rare or threatened. This includes:
- 62 species are listed as threatened (critically endangered, endangered or vulnerable) in Victoria
- 9 species listed as endangered or vulnerable in Australia under the Federal Environment Protection and Biodiversity Conservation Act 1999
- The Rosella Spider Orchid, once scattered throughout southern and central Victoria (pictured)
- The Charming Spider Orchid
Nillumbik is known for its diverse orchid population with approximately 143 different orchid species recorded. The majority of the known populations of the Wine-lip Spider Orchid are also restricted to the region.
The Shire also supports several populations of the critically endangered Round-leaf Pomaderris, a species only known from a small number of populations in the ranges to the north and east.
You can find out more about threatened flora species below, from the 'Live Local Plant Local' publication or by taking part in one of our environmental activities.
Threatened plant species
Rosella Spider Orchid (Caladenia rosella)
There are currently less than 150 known Rosella Spider-orchid plants in the wild. The Rosella Spider-orchid (Caladenia rosella) grows to 20cm tall when flowering and has a single leaf which is 4-9cm long and covered with fine hairs. The base of the leaf stem is greenish to reddish-purple coloured. Flowers are pink with a musky fragrance and blossoms from August to September.
Although the Rosella Spider-orchid was once scattered throughout Central Victoria, it is now only known from four populations that are restricted to Nillumbik Shire.
The Rosella Spider-orchid has been impacted from the clearance of habitat, rabbit grazing and grassy weeds. Grassy weeds such as Panic Veldt-grass and Quaking Grass smother the orchid and compete for nutrients and water. Other threats include housing developments and land clearing, predation by White-winged Choughs, inappropriate fire regimes and habitat disturbances. Loss of the key pollinator species, a bee of the Leioproctus genus, due to a reduction in the diversity of the orchid’s habitat, including the removal of indigenous daisies, wattles and peas, is also an important factor in the decline of the Rosella Spider-orchid.
The Rosella Spider Orchid is listed as endangered under the Federal Environment Protection and Biodiversity Conservation Act 1999. It is also endangered in Victoria and listed as threatened under the Flora and Fauna Guarantee Act 1988. These acts have helped to protect the remaining populations of Rosella Spider-orchid and recovery actions for this species are currently being undertaken including protecting populations with small metal cages, hand pollination and intensive weed control works.
A program to propogate these orchids is underway with help from the Royal Botanic Gardens, Melbourne.
Matted Flax Lily (Dianella amoena)
The Matted Flax-lily (Dianella amoena) is a tufted, mat forming lily which has small blue-violet flowers with orange strumae (swellings at the base of the anthers). Plants flower from October to April and are followed by purple-blue berries. The Matted Flax-lily can reach up to 90cm in height when flowering and can form loose clumps up to 5 metres wide. They prefer Grassland and Grassy Woodland habitats. In Nillumbik it has mainly been recorded in Valley Grassy Forest and Creekline Herb-rich Woodland.
The Matted Flax-lily is mainly associated with the volcanic plains, but is located from the south west, north east and south east of Melbourne. Small populations also occur in Eastern Victoria. The majority of the remaining population are located in fragile areas such as on roadsides, railway lines and private land or on small reserves in urban environments. In Nillumbik, the species is only found in several scattered small populations including the reserves at Eltham South and St Andrews and on roadsides around Doreen and Plenty.
It is listed as endangered under the Federal Environment Protection and Biodiversity Conservation Act 1999. It is also listed as endangered in Victoria and is threatened under the Flora and Fauna Guarantee Act 1988. The main threats to the Matted Flax-lily include habitat destruction and disturbances, particularly due to development, rabbit and stock grazing, population fragmentation, weed invasion and competition. Fencing of known populations has reduced the impact of grazing and weed control around the vicinity of the plants helps to reduce competition.
Round-leaf Pomaderris (Pomaderris vacciniifolia)
The Round-leaf Pomaderris (Pomaderris vacciniifolia) is a medium shrub that grows to 3-4 metres high. It has small round leaves that are dark green and shiny on the upper surface and white below. The flowers are small and creamy white which occur in the leaf axil and bloom from October to November. Within Nillumbik the species are found in Valley Grassy Forest EVC dominated by Yellow Box and Candlebark. Around St Andrews it is also found within Creek-line Herb-rich Woodland EVC dominated by a Swamp Gum Eucalyptus ovata in wetter sites and Yellow Box Eucalyptus melliodora and Candlebark Eucalyptus rubida along alluvial terraces.
The Round-leaf Pomaderris are only recorded in Victoria and are found in small populations in mountain forest around Kinglake, Castella and Toolangi. In Nillumbik the species are found on roadsides in St Andrews and at reserves in Christmas Hills, St Andrews and Eltham. The Round-leaf Pomaderris is listed as threatened under the Flora and Fauna Guarantee Act 1988 and is endangered in Victoria. It is currently being considered for listing under the Environment Protection and Biodiversity Conservation Act 1999.
Recently, concerns have risen about the plant failing to reproduce successfully due to a number of factors including the previous prolonged drought and preference for a particular type of habitat. Other threats include natural and anthropogenic disturbances such as land clearance, browsing by deer, rabbits and hares, and weed invasion.
In February 2009, The Black Saturday Bushfires destroyed 98% of Kinglake National Park. This had a devastating impact on the Round-leaf Pomaderris and other native flora and fauna. Few years later Kinglake National Park is on its way to recovery. Populations of Round-leaf Pomaderris were surveyed and surveys have shown impressive regeneration of this species within Kinglake National Park and a healthy population now occurs within the national park.
Wine-lipped Spider Orchid (Caladenia oenochila)
The Wine-lipped Spider-orchid (Caladenia oenochila) is a tall (to 30cm), hairy, erect, terrestrial orchid which has a wiry stem. It displays 1-2 sweetly perfumed flowers which are pale yellow-green with very dark red hairs on the tips and outer surface. The labellum or lip is undivided and is deep, dark red which is paler towards the base.
Wine-lipped Spider-orchid mostly occupies hillcrests and exposed hill slopes. Most of the sites where it has been recorded are consistent with Box Stringybark Woodland (Grassy Dry Forest). Vegetation commonly associated with Wine-lipped Spider orchids typically supports a rich diversity of shrubs, particularly peas and wattles, with a high diversity of grasses, daisies and other orchids. It also occurs in damp and valley sclerophyll forest and is associated with Creekline Herb-rich Woodland, Herb-rich Foothill Forest and Valley Grassy Forest. It prefers moist, well drained soils. The Shire of Nillumbik contains one of the largest concentrations of Wine-lip Spider-orchid in Victoria. This includes the largest known population of the species (over 800 plants in a reserve in St Andrews). All other populations are relatively small and many have declined over the last decade. The species is also localised in parts of outer-eastern Melbourne, including within the Dandenong Ranges.
The Wine-lipped Spider-orchid is listed as Vulnerable in Victoria. This rare orchid is uncommon due to habitat loss from land development. Other threats include weed invasion, grazing, predation, soil disturbance, shading from built structures and vegetation clearance. To conserve and minimise impacts of grazing and predation on the Wine-lipped Spider-orchid fencing and/or caging has been implemented. Hand pollination is often undertaken due to the absence or low abundance of natural pollinators and seed is collected and sown to help increase population sizes.
A program to propogate these orchids is underway with the help of the Royal Botanic Gardens, Melbourne.