The Grange - Flora (Plants)

The Grange Flora Plants

Heathland Plants in The Grange: Special Features

Leaf Characteristics

A factor that distinguishes plants within heathlands communities is the characteristic sclerophyllous leaves that have thick waxy coverings and sunken stomata. This protects the stoma from the elements, to reduce water loss from the leaves.

Leaf cell walls are thick and contain tannins, resins and essential oils. Many plants in the upper layer have smaller leaves and some are typically ericoid, having a hard waxy upper surface and a deeply grooved lower surface.

These leaf characteristics help prevent loss of water from the plants in different ways. Their shape reduces the amount of surface area to volume ratio. The thick cells and waxy coatings keep moisture in the leaf. This is important for their adaptation to such dry soils, and the Australian climatic factors in of infrequent rain.

Root Systems

Lignotubers

Tubers

Rhizomes

All Underground Stores of Plant Food

Many of the heathland species have specialised root structures such as underground lignotubers, rhizomes, bulbs and tubers. These underground organs can survive fire and rapidly regenerate new shoots. They help heathland plants cope with fire, which is a frequent occurrence in heathland communities.

In nutrient-deficient soils where heathlands are found, specialised root systems develop in between the decomposing litter and soil surface.

These roots have developed mutualistic relationships with mycorrhiza within the soil which provide the plants with a particular type of phosphate synthesised from the orthophosphate that is released in the decomposition of leaf litter during Spring. In heathland plants. these mycchorhizae also aid the uptake of water and other nutrients, such as zinc and copper. Mycorrhiza, to an extent, replaces the root hairs on a root.

Bradysporous Fruits

A number of plant species produce hard woody fruits that retain their seeds for a number of years, until the hard case is cracked by fire, releasing the seed. As a result of this bradysporous characteristic, regeneration of these species by seedlings is usually dependent on fire. Bradyspory is typical of the Casuarinaceae, Myrtaceae and Proteaceae families.

Hard Woody
She-oak Cone
Casuarinaceae

Woody Gum-nuts
Open After Fire
Myrtaceae

Seed Dispersal by Ants

Many of the seeds released from heathland plants are large and contain a structure known as an elaiosome, which is attractive to ants. Seed dispersal by ants is a distinctive feature of heathland plants.