​Greetings fellow Foxies,
 
My journey into underground plant parts continues.
Rhizomes are basically underground stems, which are particularly common in monocotyledons. Domestic examples are your lawn, ginger and turmeric.
Basically, stem like roots radiate out from the seedling plant that have nodes at regular intervals. Each node sprouts roots and a vegetative shoot called a culm that forms a flower.
Rhizomes are common in the bush, particularly on sedges, rushes and native grasses. These plants can live for decades. The central parent plant often dies as clones radiate outwards to form a circle. Spinifex is a great example.
In the image of a yellow kangaroo paw from my garden, fleshy rhizomes store starch to maintain the plant over summer when the culms often die off, and to help produce new culms as flowers on the old ones mature and die.

​As a very general rule of thumb there are two main types of rhizomatous plants.
• Ones with horizontal rhizomes that spread underground, which enables them to survive severe fires. Members of this group have the fleshy rhizomes and often occur in large patches.
• Ones with more vertical rhizomes that form very clumpy plants that are less fire tolerant. These tend to be more common in less fire-prone areas like wetlands and may have other features that protect them from fire.

​Have you noticed how difficult it can be to shake the sand off grass weeds after you pull them out? Many monocotyledons have sand binding roots. These secrete a gum from their roots to form a sandy ‘armour’ that helps to protect them from heat, drying and perhaps root chewing insects. Australian native plants produce very tough long-lasting sand binding root covers that persist long after the plant has died and provide important protection against erosion.

Kangaroo paws (Genus Anigozanthus) have rhizomes and sand binding roots.Two local plants in the Anigozanthus genus are Cat Paw Anigozanthus humilis (common on sandy soils) and the Little Kangaroo Paw Anigozanthus bicolor (found at Highbury B Block)

Greetings fellow Foxies,
 
 “Unravelling the Secret Lives of Plant Root Systems” has explained another interesting feature of our local bush: Large groups of the same small perennial plants amidst an otherwise diverse shrub understorey.
These plants usually reproduce vegetatively rather than from seed.
It all comes back to plant strategies for coping with fire.
Some plants only reproduce sexually by seed (obligate seeders) and some only asexually by vegetative growth (obligate resprouters) and many do both.
Root suckering plants send shoots (to become plants) up from spreading root systems that are deep enough to be protected from fire.
They tend to be more common on fire-prone sandy surfaced soils.  and in higher rainfall areas.
 As resprouters don’t rely on fire for seed germination, they can outcompete seeders in the absence of fire. A downside is that each resprouter plant is a clone, putting them at risk of extinction when conditions change. They overcome this by being very-long lived with plants commonly living for 50 to 100 years. Some resprouters live to 1000! During this time random mutations enable create the genetic variation that enables change.
Common Popflower Glischrocaryon aureum produces few fertile seeds, along with clonal members of the Goodeniaceae family (Goodenias, Dampieras). All those lovely flowers for the the pollinators but few  seeds!

In the image below lines of white Goodenia/Goodenia scapigera clones that have sprouted from lateral roots in Foxes Lair.

Another example is Persoonia quinquinervis. Persoonias are the only members of the Proteacea family that rely on mycorrhizae instead of cluster roots to enhance water and nutrient uptake.

​Here is a strange one. There are three patches of quandongs (Santalum acuminatum) in Foxes Lair. they flower annually but I have never found a nut. When a fire swept through one side of a clump that was bisected by a road there was no difference in density between burnt and unburnt sides. This indicated to me that there was no seed germination in the unburnt side. They must all be clones.

Greetings fellow Foxies,
Visitors to Foxes Lair each summer could be forgiven for thinking that many understorey plants have died, but each winter they burst into life again.
 There are many plant strategies for coping with our seasonal droughts.
Each November, the marri trees drop some leaves to reduce their water use, and orchids survive as twin underground bulbs (‘orchis’ is the Greek word for testicle).
 True specialists are resurrection plants that completely dry out but, become green and active within days of rain. Examples are lichens (OK not plants) and Borya species “Pincushion plants’ on granite rocks (see Borya sphaerocephala on left).

​Many other plants partially shrivel up and change colour to ultraviolet resistant purple, red, and yellow, but remain alive in most seasons. However it takes days for them to recover after rain,  and plants will die in severe droughts.
The compact bush tucker plant Kickbush (Astroloma acervatum) is a common example

​Allocasuarinas (sheoaks and tammars) also markedly change colour as shown in the Dwarf Tammar (Allocasuarina humilis) images from near the Claypit. I noticed that there were colour differences within the plant where some branches were more water stressed than others.
Random comment – why do taxonomists use the Latin word humilis for smaller?
As a person of moderate stature, I regard this as heightist bias, and certainly feel no humility towards my larger brethren (poor souls).

​This interesting extract from a book edited by Professor Hans Lambers is a great read for those wishing to understand more about drought tolerance of our native plants.
 Have you ever wondered why Australia has no cacti and few succulents compared to other countries?
Succulent plants rely on salts in their cells to retain large amounts of water. Their evolution has not been favoured on most of our soils which have formed on very leached and weathered materials, except in saline basins where one finds salt tolerant succulents like Bluebush, Pigface, and Samphire.

Greetings fellow Foxies,
The peak of the flowering season has past and the drive-snap crowd has departed, but for observant nature lover there is beauty in post-flowering new plant growth. Proteaceae are particularly intriguing with a myriad of shapes and colours and woolly or hairy growth. These plants are superbly adapted to thrive in the lateritic soils that they create.
I am so lucky to be able to observe the annual cycle of life- death- rebirth of the plants and animals in Foxes Lair. It provides a reality check in the increasingly chaotic outside world.