Tag Archives: May

Mayfly Mystery

The Mayfly Orchid is a small orchid with very dark reddish brown flowers with long, hair-like sepals.  It flowers from late July to August.  One might question what sort of insect was behind the naming of this orchid, which does not even flower in May.  Mayflies are an insect with which many of us are not acquainted.

Nemacianthus caudatus

Close view of a typical flowering Mayfly Orchid

One source attributed the naming or the orchid being similar to the long legs of a Mayfly.  However, a quick search in the Internet revealed that Mayflies have fairly short legs, as in the image below:

It turns out that it is the appendages on the end of the abdomen that the sepals of the Mayfly Orchid resemble.  Mayflies usually have three tails (two cerci, one middle filament), although the middle tail is rarely reduced or absent.  All the tails are longer than the body, thread-like and similar in size.  Thus the three tails correspond with the three long sepals of the Mayfly Orchid flowers.

This is only half of the story; mayflies occur in swarms and these resemble colonies of Mayfly Orchids.

Nemacianthus caudatus

A colony of Mayfly Orchids in the Adelaide hills

Mayflies are a sign of summer in parts of the United States of America Source: http://www.severnsound.ca/SSEA_Mayflies.htm

Adult Mayflies are short-lived.  Most live for one or two days, but some for only a few minutes.  They form mating swarms.  Some swarms are quite impressive, even on Doppler weather radar.

So you may want to keep a lookout for colonies of Mayfly Orchids in August and see if you can imagine a swarm of insects with three long tails on their abdomens.

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Small Wonder

Corunastylis sp. Adelaide Hills – Midge Orchids

This genus would have to be one of the most frustrating orchids to identify (at least I think so), and when found in the wild only looks like a twig sticking out of the ground, but when looking at a picture is a surprisingly beautiful flower.  However Bates 2011 said, “Basically if one finds a woodland species in the Mount Lofty Ranges it will be this taxon,” so I guess it is not that hard to identify.

The variety of colourings

The variety of colourings

So it is the Corunastylis sp. (Adelaide Hills), an unobtrusive flower showing itself from late February to May.  The distinguishing feature of this orchid is its labellum which is so tiny, and so difficult to get under to see!  The whole plant stands under 10 cm, with many small brown and green flowers along the stem.  It is fairly widespread in South Australia, growing from Eyre Peninsula across to the Flinders Ranges, and down to the South East and Kangaroo Island.

2009 036a

Note: this is the Mt. Billy species

This orchid does have a leaf which wraps around the stem of the plant.  However it can be difficult to see.  The flowers are pollinated by a small little fly.  It is quite common to find the little pollinator sitting on the flower, with pollen on its back.

Mostly the orchid is found in sandy soil, or open areas.  Quite often it seems to enjoy living dangerously, growing in the middle of tracks and paths.

This genus is not just unique to Australia, as there are other species which can be found in New Caledonia and New Zealand.

A remaining captual

A remaining capsules

Often the finished capsules of the orchids can be found quite some time after flowering, right into spring.  The above picture shows that this plant was pollinated and has produced some swollen capsules.

Corunastylis sp copy

Reference:
Bates, R. (2011) South Australia’s Native Orchids. Native Orchid Society of South Australia Inc, p.455.

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Nice and Early

Eriochilus cucullatus – Parson’s Bands

The Parson’s Bands is a small white flower that appears from late March to May and is reasonably common.  The flowers always appear before the leaves, which can then last some time after flowering has finished.  The whole plant can stand up to fifteen cm high, and usually has one flower per stem, and on rarer occasion can have up to three flowers on one stem.  This orchid appears to like growing in small open places, including rocky places and old tracks.

Eriochilus cuculata (1)

Within the Eriochilus cucullatus species in South Australia there are several subspecies with Eriochilus sp Hills woodland being the most commonly found.  In Victoria only E. cucullatus exists, but there are several other species found in Western Australia.

Eriochilus cuculata (19)

This orchid is believed to be pollinated by a small native bee, which the orchid attracts through its flower’s colouring and scent.  The picture above shows some pollinia on the flower’s labellum.

After it flowers, or towards the end of flowering, the leaves of this orchid begin to appear.  They are a dark green-grey colouring, with a textured top.  If leaves are found at a site, it is probably a good idea to check these areas next autumn for any flowers.

Eriochilus cucullatus

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The long and short of it

Urochilus sanguineus – Maroon Banded Greenhood

This species used to be listed as a Pterostylis, and is similar strucurally to the Bunochilus.  Often it is found with Bunochilus, but they have not been known to hybridize.  It has a labellum which is sensitive to touch.  The plant will either produce a flowering stem, or a sterile leaf.

Winter orchids: Linguella sp. Hills nana, Urochilus sanguineus

This species flowers from May to September, and can be found in most regions of South Australia, as well as Western Australia, Tasmania and Victoria.  It is believed that this plant may have originated from the west, as most Urochilus species are endemic to Western Australia.  South Australia only has this species.

Quite often I’ve seen a variety of heights of these orchids, on the same site, at the same time.  This is mainly due to the nutrients of the soil where the plants are growing.  The dwaft plants are called ‘depauperate’.  Another feature of these orchids is they can grow in clumps or as a single plant.

The flowers can be difficult to photograph as they are very darkly coloured.  However with the afternoon sun coming through them they are beautiful.  Taking photos of them with a flash makes these flowers almost look black, and hides the loveliness of these flowers.

I’ve provided two pictures below of this species, the first from the southern and the second from the northern Mt. Lofty Ranges to show there is really no difference despite location.  Overall the species only varies in height, and the flowers fade with age.

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Facing away

Diplodium sp.- Shell Orchid

In this post, I will be dealing with Diplodium robustum, Diplodium sp. Adelaide Hills, and the hybrid the occurs from both.  These plants flower between May and August.

The plants of this species will either have a small rosette of leaves or a flower with leaves growing from the stem.  These orchids tends to form large colonies, but only 10% will flower.  An interesting observation is that these flowers will grow facing the slope.  It could be that this is where the pollinator will come from.  The reason is not known, but it does make it hard to photograph the front of the flower.

All the flowers are facing in one direction.
Note the little rosettes around the plants

Another example of the flowers all facing the banking

The two parent species of Diplodium are determined by the length of the spike on the end of the dorsal sepal.  D. robustum has long spike and is pictured below, left.  D. sp. Adelaide Hills has a short spike and is pictured below, right.  The hybrids are more likely to finish flowering before their parent plants.

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Common in winter

Cyrtostylis robusta – Winter Gnat Orchid or Robust Gnat Orchid

This species is very similar to its sister Cyrtostylis reniformis.  The main difference is the flowering time with C. robusta flowering in winter and C. reniformis flowering in spring.  C. robusta tends to have smooth green leaves while C. reniformis has strongly veined aqua green leaves.  C. robusta has a larger flower that the other species.

Here is a small clip of some Cyrtostylis robusta.  There is a little fly on the labellum of the central flower.  However it is not a pollinator as the fly can not reach the pollen.  Just because an insect is on the flower does not automatically mean it is the pollinator.  The pollinator of these flowers is long-legged fungus gnats from the diptera family.

This species has a widespread distribution from Western Australia, through most of South Australia and into Victoria and Tasmania.  It grows in a variety of habitats, but prefers a sheltered area.  It can grow in exposed areas, but these plants do not tend to flower.  It is a reasonably common orchid.

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The little hardy one

Acianthus pusillus – Mosquito Orchid

This orchid is so common, many orchid enthusiasts overlook it when on an orchid excursion.  It is small, difficult to photograph, and as it is very close to the ground, many don’t think it is worth the effort getting all the way down to photograph it.  It is a tough and hardy little plant.

Nemacianthus caudatus is a similar species but has longer sepals.

It is very small.  On a healthy flower stem of just over 10cm, it may have over 10 flowers.  The flowers are less than half a centimetre high.  Coupled with its size, and dark colour it is very difficult to photograph.  I’ve observed that photos taken with a flash make the stem and flowers appear a dark brown/red colour but without a flash it looks more purple.  It has a distinctive heart-shaped leaf which is purple underneath.  Its sister is Nemacianthus caudatus (Mayfly Orchid), which flowers after the Mosquito Orchid.

It does have a long flowering time from April to July.  This occurs if they are not pollinated.  The little pollinator is a small fly, which is difficult to find even on a large colony of plants.  However on some of these plants we had at home I notices some of these pollinators.

Like most orchids, the little mosquito orchid tends to grow in shady areas.  This orchid is often found near the bases of trees, in a moist little corner.  It does have a tendency to grow in colonies.

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