Plant of the week #5

Leptospermum myrsinoides
(heath tea-tree)

A brief description: A common shrubby species throughout it's range, the heath tea-tree grows to about 1-2 meters in height. However it is often found as an understory shrub in Eucalyptus woodlands and is much smaller. The 5-petal flowers are white (sometimes pink) and appear in spring.

Taxonomy: From the same family as the Eucalyptus genus, Myrtaceae, it is one of about 85 species. Most species are endemic to South-Eastern Australia, with one found in New Zealand and another in Malaysia.

Distribution: SA, VIC, rare but reported in NSW (mostly in the SE).

Conservation status: Locally common in SA and VIC, not considered at risk in the wild.

Interesting things about tea-tree: Various species in this genus are commercially important for the garden industry and also for honey producers. Dense plantings of tea-trees are popular as hedges and there are many cultivars that are common garden plants (particularly due to the drought-tolerance of older plants). Honey made from the nectar of some species has been found to have antibacterial and antifungal properties.

Plant of the week #4

Cassytha pubescens
(Downy Snotty-Gobble) 

A brief description: Also known as dodder-laurel, devil's twine, jungle string or love vine, this interesting plant is actually a parasite. All species in the genus are hemiparasites, meaning they still photosynthesise and tap into the host plant's xylem (taking water and the associated dissolved nutrients) but not sugars. It is rootless as an adult (although the seedlings have roots) and is completely dependent on its host for survival. Flowering and fruiting in summer, the picture above shows some flowers in bud and opening, as well as some immature fruit. The host in this case is an Acacia pycnantha, although it is a generalist parasite and will grow on pretty much anything (even barbed-wire fences!).


Taxonomy: The taxonomy of this genus is not well researched. There are approximately 23 species, 16 of which are endemic to Australia. The genus is placed within Lauraceae, often within it's own subfamily as it's so weird. *It is unrelated to the Dodder species in the Cuscuta genus. They're a completely different family (Convolvulaceae) and are an excellent example of convergent evolution as they look very similar but are completely unrelated, and physiologically very different*

 Distribution: Eastern states; Coastal SA, Vic, Tas, NSW and QLD. Also found in New Zealand and Japan (introduced).

Conservation status: Locally common, not considered at risk in the wild. Distribution is typically patchy


Interesting things about downy snotty-gobble: There are many, where should I start?! (this is the plant I'm studying for my PhD, so I'm perhaps a bit biased :P). It has been seen to damage some weedy species in South Australia, even killing Gorse (Ulex europaeus) and Scotch Broom (Cytisus scoparius) but not the native species. This is thought to be due to the native species co-evolving with Snotty-Gobble.
The other thing I find rather interesting, is the seedling stages of this parasite. It germinates and grows for the first 6-8 weeks with a short root (usually no more than a couple of cm long) which dies back after it's found a host and wrapped itself securely around it. This means if there's a disturbance such as a fire, the adults are all toasted and it's up to the seeds left in the soil to re-establish the population. Interesting, yes?

Plant of the week #3

Corybas diemenicus
(veined helmet orchid) 

A brief description:
A winter flowering orchid, this species prefers cool damp Eucalyptus woodlands. Being small (about a centimeter or two in height) they are easily missed - look for the heart-shaped leaves with prominent veins appearing in May-July. The flowers, like all orchids, are insect pollinated, and appear in late winter.

Taxonomy:
The veined helmet orchid is one species of about 100 that belongs to the genus Corybas (Family: Orchidaceae). This genus is found throughout Oceania, with about 20 Australian endemic species.

Distribution: Eastern states; eastern SA, Vic, Tas, and NSW (south-eastern coast).

Conservation status: Locally common in Eastern Australia, less common in SA; not considered at risk in the wild

Interesting things about the veined helmet orchid: 
Veined helmet orchids like cool, moist environments. They're often found on the underside of logs and around cool, rocky streams. Even in large patches all the flowers tend to face south, and produce quite a spectacular display in large quantities.

Plant of the week #2

Stylidium graminifolium
(grass trigger-plant)

A brief description:
The grass trigger-plant is a spring flowering plant found predominantly in moist to dry eucalypt woodlands throughout south-eastern Australia. Emerging in late winter, leaves are up to mid-shin height, with the flower-spike up to knee height. Flowers vary from hot pink to white with pink streaks (as above), with the inflorescence covered in small black hairs.

Taxonomy:
The grass trigger-plant is one species of about 130 that belongs to the genus Stylidium (Family: Stylidiaceae). Most species are Australian, however there are some found throughout south-east Asia.

Distribution: Eastern states; eastern SA, Vic, Tas, NSW (eastern coast) and QLD (south-east).

Conservation status: Locally common; not considered at risk in the wild

Interesting things about trigger-plants:
The flowers of trigger-plants are insect pollinated, and it is from the flowers that the plant derives both it's common and genus names. The flower consists of 5 petals (4 clearly visible, one tucked back up behind the trigger) and fused stamens (2) and style that form a trigger. This trigger is pulled backwards (like cocking a gun), and when an insect lands on the flower it is released, swinging forward and stamping pollen onto the back of the insect's head. You can see this trigger clearly locked-and-loaded in the photo below. Unfortunately I wasn't smart enough to trigger it and take a before/after photo. Perhaps next time? ;)

Plant of the Week #1

Amyema miquilii
(common box mistletoe)

A brief description:
Common box, or drooping, mistletoe is a hemiparasitic plant. This means it takes water and the associated dissolved nutrients (such as nitrogen) from it's host, through a structure called a haustorium. Mistletoes are stem parasites, and as such depend on their hosts for survival. Because of this, contrary to popular belief, they rarely kill their hosts. The red flowers appear in late summer and throughout autumn, and the fleshy fruits develop soon after flowering. Pollination and fruit dispersal is bird assisted, with the seeds leaving the birds gut encased in a sticky, glue-like substance. The birds then wipe this against a branch (to remove it), and the seed sticks to the branch. If it has been deposited on a suitable host, the seed will quickly germinate, and forms a strong attachment to the host.

Common hosts for this species include members of the Eucalyptus and Acacia genera.

Taxonomy:
The common box mistletoe is one species of about 100 that belongs to the genus Amyema (Family: Loranthaceae). There are about 35 species found throughout Australia.

Distribution:
A. miquilii is present in all mainland states of Australia

Conservation status: Common; widespread (throughout Australia)

Interesting things about mistletoes
Mistletoes are key food sources for birds (both pollinators and fruit eaters), as well as insects such as butterfly larvae. Mistletoes can also be nutrient accumulators. Being hemiparasitic, they are not water limited during droughts, as their hosts provide a reliable water source. Because they can rapidly use water without drying out, the nutrients carried by that water are deposited in the leaves and nutrients can accumulate. Mistletoes have been known to directly affect the distribution of nutrients in the landscape, with their leaves releasing patches of nutrients back into the soil as they decay.