Rough shell orchid facts for kids

The Pterostylis aspera, also known as the rough shell orchid, is a special type of orchid. It is found only in the south-west part of Western Australia. This means it is endemic to that area.

Like many other "greenhood" orchids, this plant looks different depending on whether it is flowering or not. When it's not flowering, it has a group of leaves that lie flat on the ground, forming a rosette. But when it's time to bloom, a single flower grows on a tall stem, and the leaves are found on this stem instead. The flower of the rough shell orchid is usually white with green and reddish-brown stripes. It also has a short, straight part called a labellum.

What the Rough Shell Orchid Looks Like

Pterostylis aspera is a plant that grows from an underground tuber (a swollen part like a small potato). It is a perennial plant, meaning it lives for more than two years. It is also deciduous, which means some parts of it die back each year, but the plant itself survives underground.

When the plant is not flowering, it has a rosette of bluish-green leaves. These leaves lie flat on the ground. Each leaf is about 6 to 20 millimeters (0.2 to 0.8 inches) long and 4 to 17 millimeters (0.2 to 0.7 inches) wide.

Flowering plants usually have only one flower. This flower is about 22 to 30 millimeters (0.9 to 1.2 inches) long and 10 to 12 millimeters (0.4 to 0.5 inches) wide. It leans forward on a flowering stem that is 60 to 200 millimeters (2.4 to 7.9 inches) tall. The stem also has three to five leaves, each about 20 to 30 millimeters (0.8 to 1.2 inches) long and 3 to 5 millimeters (0.1 to 0.2 inches) wide.

The flowers are white with green and reddish-brown stripes. The top sepal (a leaf-like part of the flower) and the petals are joined together. They form a hood, or "galea," over the column (the central part of the orchid flower). This top sepal has a sharp point. The side sepals are held close to this hood. They have narrow tips that are about 30 to 35 millimeters (1.2 to 1.4 inches) long. There is a wide space, called a sinus, with a small notch between their bases.

The labellum is the lip-like part of the orchid flower. For this orchid, it is about 13 to 15 millimeters (0.5 to 0.6 inches) long and about 4 millimeters (0.2 inches) wide. It is mostly straight and just barely visible above the sinus. The rough shell orchid flowers from May to July.

How the Rough Shell Orchid Got Its Name

The rough shell orchid, Pterostylis aspera, was first officially described in 1989. Two botanists, David Jones and Mark Clements, gave it its scientific name. They described it from a plant they found near Eaton. Their description was published in a scientific book called Australian Orchid Research.

The second part of its scientific name, aspera, is a Latin word. It means "rough," "harsh," or "uneven." This name refers to the tiny hairs found on the labellum of the flower, which make it feel rough.

Where the Rough Shell Orchid Lives

The rough shell orchid grows in areas with shrubs and trees, like shrubland and woodland. You can find it between Dongara and Jerramungup in Western Australia. It grows in several different natural areas, including the Avon Wheatbelt, Esperance Plains, Jarrah Forest, Mallee, and Swan Coastal Plain. These are all different types of biogeographic regions, which are areas with similar plants, animals, and landscapes.

Protecting the Rough Shell Orchid

The Government of Western Australia's Department of Parks and Wildlife has listed Pterostylis aspera as "not threatened." This means that, for now, there are enough of these orchids in the wild, and they are not considered to be in danger of disappearing.