Hooded mosquito orchid facts for kids

The Acianthus collinus, also known as the hooded mosquito orchid or inland mosquito orchid, is a special type of flowering plant. It belongs to the orchid family called Orchidaceae. This orchid is found only in New South Wales and Victoria in Australia, meaning it is endemic to these areas. It's a ground-dwelling herb that grows from the soil. It has a single, heart-shaped leaf and usually produces between two and nine flowers. These flowers are often pinkish and look a bit see-through, with reddish marks. You can find these orchids growing in groups on sheltered hillsides in open forests, especially on the western slopes of the Great Dividing Range.

What the Hooded Mosquito Orchid Looks Like

The Hooded Mosquito Orchid is a ground orchid that lives for many years (it's a perennial). It loses its leaves in some seasons (it's deciduous) and grows in a way that new shoots come from the side of old ones (it's sympodial). Each plant has one smooth (glabrous), dark green leaf shaped like a heart. The underside of the leaf is reddish-purple. This leaf is usually about 15 to 32 millimeters (0.6 to 1.3 inches) long and 14 to 30 millimeters (0.6 to 1.2 inches) wide. It sits on a stalk that is about 3 to 6 centimeters (1.2 to 2.4 inches) tall.

The plant produces a thin flower stem (called a raceme) that grows 6 to 15 centimeters (2.4 to 5.9 inches) tall. On this stem, there are usually two to nine flowers, spaced out nicely. Each flower is about 8 to 11 millimeters (0.3 to 0.4 inches) long.

Let's look closely at the flower parts:

• The top petal, called the dorsal sepal, is shaped like an egg. It's about 6 to 8 millimeters (0.2 to 0.3 inches) long and 4 to 5 millimeters (0.16 to 0.20 inches) wide. It's a see-through pink with reddish lines and spots, and it forms a little hood over the flower's central part, called the column.
• The two side petals, called lateral sepals, are 7 to 11 millimeters (0.3 to 0.4 inches) long and about 1.3 millimeters (0.05 inches) wide. They are thin and pointed, pinkish with a red stripe down the middle. They often cross over each other below the lip of the flower.
• The other petals are similar in color and are about 3 to 5 millimeters (0.1 to 0.2 inches) long. They are narrow and spread out wide.
• The most interesting part is the labellum, which is the orchid's lip. It's dark purplish-red to purplish-maroon, about 5.5 to 6.0 millimeters (0.22 to 0.24 inches) long and 3.0 to 3.5 millimeters (0.12 to 0.14 inches) wide. It's roughly heart-shaped when flattened, and its edges are curled under with uneven little teeth. A thick, fleshy bump (called a callus) covers most of the center of the labellum. This bump is dark purplish-red and has many tiny, pimple-like bumps on its outer half.

These orchids usually bloom from late June to August. After flowering, they produce a seed pod (called a capsule) that is 6 to 8 millimeters (0.2 to 0.3 inches) long and 2.0 to 3.0 millimeters (0.08 to 0.12 inches) wide. It can be straight or slightly curved.

You can tell this orchid apart from a similar one, Acianthus fornicatus, because its flowers are translucent pinkish, and its petals and top sepal are narrower. Before 1999, this orchid wasn't known to grow in Victoria. Now, it's found in a few places there, with hundreds of plants in each group. It's easy to miss, so it might be growing in other areas too. In Victoria, it's easy to spot because of its wide sepal.

How the Hooded Mosquito Orchid Got Its Name

The scientific name Acianthus collinus was first officially described by a botanist named David Jones in 1991. He wrote about it in a scientific paper called Australian Orchid Research. He found the first specimens (samples) of this orchid with Mark Clements in the Conimbla National Park.

The second part of its name, collinus, comes from a Latin word that means "growing on a hill." This name was chosen because this orchid usually grows on hillsides.

A few years later, in 1995, another botanist named Paul Joseph Kores suggested that A. collinus and four other similar orchid species might actually be the same as Acianthus fornicatus. This idea means they should be considered the same plant, just with different names. The Royal Botanic Gardens, Kew, a very famous botanical garden, has accepted this idea.

Where the Hooded Mosquito Orchid Lives

This orchid grows in groups, usually on gently sloping hillsides within open forests. You can find it in several regions of New South Wales, including the Northern Tablelands, Central Tablelands, Southern Tablelands, North West Slopes, and Central West Slopes. It also grows on Black Mountain in the ACT and in the Chiltern-Mt Pilot National Park in Victoria.

Protecting the Hooded Mosquito Orchid

The Hooded Mosquito Orchid is listed as "vulnerable" under the Victorian Government Flora and Fauna Guarantee Act (1998). This means that its population is at risk, and it needs protection to make sure it doesn't disappear.