Cumberland Plain Woodland typically has a canopy of gum trees (species of Eucalyptus, 10-20 m high) with a grassy and herbaceous understorey. There may be scattered clumps or thickets of shrubs.
The multitude of groundlayer plants are not big and showy like the Banksias and Grevilleas of the sandstone areas, but small delicate creatures that need a careful eye to distinguish between them. Modern photography allows us to really appreciate their delicate beauty.
Our remnant woodlands at the Australian Botanic Garden, Mount Annan contain about 130 native plant species, as well as about 80 exotic weed species that have naturalised (i.e. spread into various habitats). The predominant plant family is the Grass family Poaceae with 40 species (25 native and 15 exotic), followed by the Daisies - Asteraceae with 33 species (20 native and 13 exotic), the Peas - Fabaceae with 16 species (11 native and 5 exotic) and Chenopods - Chenopodiaceae with 7 species (all native). Most of the other families are represented by only a few species. There are four fern species.
The woodland flora has most affinities with dry country areas, and many of the species also grow in drier inland NSW. Mount Annan, with an average annual rainfall of 825 mm, is part of the driest part of Sydney, and most of the native woodland plants are adapted to periodic droughts and dry conditions.
Many of the exotic species were introduced and spread around by domestic stock in the 19th and 20th centuries when the land was used for grazing and agriculture. A few of the exotic species are horticultural or ornamental plants that have run wild, notably African Olive *Olea europaea subsp. cuspidata, Cotton Bush *Gomphocarpus fruticosus, Paddys Lucerne *Sida rhombifolia and Heliotrope *Heliotropium amplexicaule.