Vegetation, Orchids and other Wildflowers of The Bibbulmun Track
The Best Wildflower Walk in the World
The bush ablaze with colour
An Orchid Species List is at the End of this Blog
The flora of Southwest Western Australia is astounding. Anyone with an interest in plants or flowers will be entranced by the variety of species. If you hike in spring and keep your eyes open, you’ll spot spectacular spider orchids, as well as hammer orchids so tiny that most people miss them. You’ll see gnarled ancient banksias and towering Xanthorrhoea. You’ll pass through stands of kangaroo paws taller than your head and cross scented marshes scattered with white flowers humming with native bees.
You’ll feel between your fingertips leathery leaves of every shape, size and colour. You’ll gasp at entire understoreys draped with purple, orange and white flowering climbers and you’ll see species so unique that they are alone in their genus. One of our most amazing experiences was in a tiny dell of brown boronia: the little flowers could hardly be seen but oh, my, the fragrance!
Boronia megastigma (Brown boronia)
Biodiversity hotspot
About the same geographic size as Southwest Western Australia, England has about 1500 vascular plant species, fewer than 50 of them unique. The other Australian land biodiversity hotspot, the Eastern Forests, also contains about 1,500 endemic plants. However, the biodiversity hotspot corner of Western Australia has approximately 8,000 – yes, 8,000! – different native plant species, about half of which are found nowhere else in Australia, let alone the world! It is an extraordinary place.
Amazing, isn’t it!
The Bibbulmun travels right across that Southwest hotspot. You’ll traverse a small amount of farmland and a few hours of plantation forest, but the vast majority of the route is through native vegetation. You’ll pass through dry sclerophyll jarrah (Eucalyptus marginata) and wandoo (E. wandoo) forests in the north, through to towering damp karri (E. diversicolor), the third tallest tree species in the world) and marri (Corymbia calophylla) forest in the central section, followed by coastal heath and dunes in the south.
So many plants to photograph!
Also in the south, you’ll walk through tingle forests (E. guilfolylei, E. jacksonii and E. brevistylis). One tree has a base circumference of 24m (26 yards), but numerous specimens are almost as big – we could easily have pitched our Triplex three person tent inside many we saw along the track!
Red tingle trees, some of them 400-500 years old, occur only in a tiny 20 sq km (7.7 sq mi) area between Walpole and Denmark. They are an ancient relic population of similar, much more widespread forests that existed here 65 million years ago, but are now confined to an ever-shrinking high rainfall area on hilltops. Atop these hills, they are at extreme risk from climate change, with nowhere to migrate for cooler or wetter conditions. The Valley of the Giants Tree Top walk right on the Bibbulmun gets you amongst the canopy of these incredible trees.
Valley of the Giants Treetops Walk
The Southwest biodiversity hotspot exists because this ancient landscape has had a climate more stable for tens of millions of years than most other parts of the world, without the extreme ice ages and glaciers that reset ecologies elsewhere. The low-nutrient soils encouraged numerous adaptations to exploit every tiny advantage to survive in every tiny niche. Others suggest that the high percentage of bird-pollinated plants also contributes to the diversity.
Best Time and Direction to Hike for Wildflower Enthusiasts
Yellow Bossiaea with purple Hovea
Spring between August and November is the best time to see the largest number of different wildflowers. October is widely cited as the best time in the south. However, this depends on the season, particularly temperature and rainfall, as well as on burn regimes.
Many local climax ecological communities that have not been burnt for a long time have dense, shady understories with fewer wildflowers. Old unburnt karri forest has the least understorey flora, but even here you’ll find different orchids, forbs and shrubs.
Orchids are often more prolific after fire. Therefore you may see numerous wildflowers in areas where we saw few, and vice versa. Keep your eyes peeled in newly blackened landscapes, too, because some orchids, such as many Prasophyllum and Caladenia species, flower only in the first spring following a hot summer burn.
Many fire-responsive Prasophyllum occur in green and black forms. The latter are very hard to spot as from a distance they resemble burnt stems!
When we hiked, the season was relatively late, but delaying a slow hike means encountering unpleasant late November and early December heat. So we were a little early in the northern section and passed numerous plants that would normally be flowering but, frustratingly, were still in bud. In fact, after the wettest July on record, the following months were so cool that, even in early November, only a handful of days on the track were sufficiently warm and sunny to open sun orchids (Thelymitra spp).
Thelymitra antennifera (Lemon scented sun orchid)
But no matter. Something is always in flower and you’ll inevitably be too late for some and too early for others. On a long slow hike, you’ll be walking through the season, which will catch you up. You’ll see so much more than anyone hiking over fewer days. Mysterious plants that were in early bud at the start of the hike and then late bud in the following weeks, are suddenly, spectacularly open and identifiable later in the walk. If you’re a plant enthusiast like me, this is wonderful stuff.
Stylidium schoenoides (Cow kicks): I’d seen rosettes of these in bud and wondered what they were. And finally, I could identify them!
Hiking southbound is best for wildflower enthusiasts. Peak flowering season starts a little earlier in the north, so you’ll be following that peak southwards. And it’s often easier to spot flowers with the sun behind you. Mycophiles should obviously hike in autumn (Karri and Tingle forests are famous for their fungi), when northbound is recommended.
Conservation – Play Your Part
Conservation challenges in the region are daunting.
Phytophthera cinnamoni (Phyophthera dieback or root rot), a soil pathogen that decimates native plants in the Myrtaceae family, was introduced on the wheels of South Australian fire trucks. It’s also spread by bicycle tyres, hooves and, sadly, hiking boots, as evidenced by dieback alongside the Bibbulmun Track itself.
Thriving banksias such as these are a key component of the ecosystem.
Within a handful of years, many otherwise pristine areas have lost their banksias, and the impact on animals such as endangered black cockatoos, and nectar feeding birds and marsupials, is devastating.
Respect signage along the track, stay on the track, and use boot cleaning stations when they have been well-maintained. Poorly maintained stations, such as one we saw with a leaking lid and a brush floating in water, may exacerbate the spread.
Xanthorrhoeas are also very sensitive to Phytophthera
When we next hike in Western Australia, we’ll carry a little spray bottle of methylated spirits to regularly disinfect our boot soles during the day, as we do when working with endangered orchid populations in South Australia.
It’s hard to believe, but the human foot has also killed many of the biggest tingle trees. Despite their massive girth, these trees are shallow rooted and extremely vulnerable to soil compaction. Avoid trampling around buttresses and please stay on boardwalks when they are present.
In spring, observant hikers will see numerous orchids along the track. Spotting these lovely flowers is so exciting it’s easy to get carried away and rush to them in your enthusiasm, but take a moment to look around before kneeling, so as not to squash leaves and flowers of nearby specimens.
Tiny Paracaleana nigrita (Flying Duck Orchid)
The Magic of Poison Peas
Native poison pea genera (eg Gastrolobium, Oxylobium) include species that contain a toxin. Native birds, animals and insects have evolved alongside these plants and are immune to the toxin. Introduced livestock die when they eat these plants, and exotic predators such as foxes and cats are so sensitive to the toxin that even eating a native animal that has itself consumed the pea, is enough to kill the predator. The presence of these plants is why quokkas and many other small ground-dwelling native marsupials and rodents survive only in the southwest of Western Australia. 1080 poison bait contains the same toxin with a minor chemical tweak, and is so useful because it targets only exotic pests.
1080 baiting programme
Orchids On the Track
We showed these friends some tiny surprises…
I spotted 85 different species and hybrids (plus a few mutants and leucistic forms) in flower during our trek and within walking distance of track towns, and many others in leaf or bud. Orchid enthusiasts may spot more than this by driving to specific orchid hotspots, but this figure is amazing considering we hiked along only one track, and within walking distance of track towns on rest days.
Although some Australian terrestrial orchids are large and striking, many are tiny in shades of brown and green, so difficult to spot. If you find an area with a few orchids, check extra closely because more cryptic species are often nearby.
…These cryptic Paracaleana nigrita (Flying Duck) flowers are only about 20 mm across, and 50-150 mm tall
If you spend three nights in town, you’ll have a day to explore the surroundings. Visitor Centres can point you in the direction of orchid hotspots, often cemeteries and local reserves. Northcliffe and Collie both have exceptional spots nearby; Balingup has a racecourse reserve a longer walk out.
If you get a taxi to the cemetery in Collie when you leave town (hiking southbound), you’ll see more microclimates within the reserve and more species than retracing your steps along the spur track.
Resources
Handy short field guides are an introduction to the flora.
Orchids of South West Western Australia is the orchid bible, and the same website is an excellent starting point with more orchids than the guides above.
Join Facebook groups such as Western Australian Native Orchids and The Wildflower Society of Western Australia (INC)
The wildflower gallery sections of this website are excellent, and the thousands of flower images on Mark Bundrett’s flickr stream are astonishing.
Orchid Gallery and Species List for Orchid Nuts
During our walk, I recorded orchids I saw in flower each day. I also saw species and genera with distinctive, recognisable leaves such as Leporella, Eriochilus and Cryptostylis, but didn’t record them, partly because in a new environment orchid ID from leaves is tricky! Besides, I spent enough time photographing orchids in flower, without starting on leaves as well!
This will be a familiar position to many photographers with creaky knees!
Most days we saw many greenhoods in the P. nana complex, but they were impossible for me to ID confidently; although they don’t appear in daily spreadsheets, it’s only because I couldn’t photograph every patch. I photographed those that seemed different, so these appear on the days I first saw them, or where I wasn’t sure and reshot one on a subsequent day. All were much, much more common than the Sectional lists suggest, especially in Karri and Tingle forests where I saw them every day.
Some days I may have forgotten to record a species, so this is a starting point only! We saw cowslips almost every day after spotting the first one; blue silkies, pink fairies and bird orchids were common throughout too.
At the time we walked – and it may be different for you – the richest days were a few days either side of Collie, and just before Walpole. On several days, we saw more than 15 different species in flower, and on a third of all days we saw 10 or more different flowering orchid species. The most we saw in flower on any one day was 22 different species.
The sections with the fewest orchids were in the tingle forests south of Walpole and between Donnelley River Village and Pemberton.
Numerous Caladenia were in bud in the northern section, and Thelymitra spp were in bud throughout. More sunny days would have greatly increased the number of Thelymitra in flower and a sunnier season will give very different results.
Have you seen different species on the Bibbulmun Track than those below? If so, please contact us with a picture (so we can confirm ID), and the location, and we’ll add it to the list as a free resource for hikers. No additional endangered species, please.
Orchid Species List
Caladenia applanta ssp erubescens (Rose Spider)
Caladenia arrecta (Reaching Spider)
Caladenia attigens ssp attigens (Forest Mantis)
Caladenia attigens attigens x Caladenia falcata
Caladenia brownii (Karri Spider)
Caladenia cairnsiana (Zebra)
Caladenia chapmanii (Chapman's Spider)
Caladenia discoides (Dancing Spider)
Caladenia ensata (Stumpy Spider)
Caladenia ferruginea (Rusty Spider)
Caladenia ferruginea x longicauda
Caladenia flava ssp flava (Cowslip)
Caladenia flava ssp sylvestris (Karri Cowslip)
Caladenia harringtoniae (Pink Spider)
Caladenia x spectabilis (Spectacular Spider)
Caladenia latifolia (Pink Fairy)
Caladenia longicalavata (Clubbed Spider)
Caladenia longicauda ssp longicauda (White Spider)
Caladenia longicauda ssp redacta (White Spider)
Caladenia longicauda x pectinata
Caladenia macrostylis (Leaping Spider)
Caladenia magniclavata (Big Clubbed Spider)
Caladenia nana ssp nana (Little Pink Fan)
Caladenia nana ssp unita (Pink Fan)
Caladenia pectinata (King Spider)
Caladenia reptans ssp reptans (Little Pink Fairy)
Calochilus uliginosus (Swamp Beard)
Cryptostylis ovata (Slipper)
Cyanicula gertrudiae (Pale China)
Cyanicula sericea (Silky Blue Orchid)
Cyrtostylis huegelii (Midge)
Cyrtostylis robusta (Mosquito)
Diuris amplissima (Giant Donkey)
Diuris corymbosa (Common Donkey)
Diuris cruenta (Kemerton Pansy)
Diuris jonesii (Dunsborough Donkey)
Diuris littoralis (Green Range Donkey)
Diuris longifolia (Purple Pansy)
Diuris magnifica (Pansy)
Diuris porrifolia (Small flowered Donkey)
Drakaea glyptodon (King in his Carriage)
Drakea gracilis (Slender Hammer)
Drakaea gracilis x livida
Drakaea livida (Warty Hammer)
Drakea thynniphila (Narrow-Lipped Hammer)
Elythranthera brunonis (Purple Enamel)
Elythranthera emarginata (Pink Enamel)
Leptoceras menziesii (Rabbit)
Lyperanthus serratus (Rattlebeaks)
Microtis alba (White Mignonette)
Microtis atrata (Swamp Mignonette)
Microtis media ssp densiflora (Dense Mignonette)
Microtis media ssp media (Common Mignonette)
Paracaleana brockmanii (Brockman's Duck)
Paracaleana nigrita (Flying Duck)
Pheladenia deformis (Bluebeard)
Prasophyllum cucullatum (Hooded Leek)
Prasophyllum fimbria (Fringed Leek)
Prasophyllum giganteum (Bronze Leek)
Prasophyllum gracile (Little Laughing Leek)
Prasophyllum hians (Yawning Leek)
Prasophyllum odoratissimum (Fragrant Leek)
Prasophyllum parvifolium (Autumn Leek)
Prasophyllum regium (King Leek)
Pterostylis barbatus (Bird Orchid)
Pterostylis crispula (Slender Snail)
Pterostylis ectypha (Murdoch Snail Orchid)
Pterostylis erubescens (Red-Sepalled Snail)
Pterostylis glebosa (Clubbed Snail)
Pterostylis karri (Karri Snail)
Pterostylis orbiculata (Small Banded Greenhood)
Pterostylis recurva (Jug)
Pterostylis turfosa (Bearded Bird)
Pterostylis vittata (Banded Greenhood)
Pyrorchis nigricans (Fire)
Thelymitra benthamiana (Leopard)
THelymitra benthamiana leucistic
Thelymitra cornicina (Lilac Sun)
Thelymitra crinita (Blue Lady Orchid)
Thelymitra flexuosa (Twisted Sun)
Thelymitra graminea (Shy Sun)
Thelymitra granitora (Granite Sun)
Thelymitra macrophylla (Scented Sun)
Thelymitra paludosa (Plain Sun)
Thelymitra vulgaris (Slender Sun)
