Pterostylis macrosepala facts for kids

The Pterostylis macrosepala is a special type of orchid plant. It belongs to the orchid family, which is called Orchidaceae. This plant is found only in one specific area: the central-west slopes of New South Wales, Australia. When a plant is found only in one place, we say it is endemic there.

This orchid looks different depending on whether it is flowering or not. Plants that are not flowering have a group of leaves shaped like a circle, called a rosette, that lies flat on the ground. But when the plant is flowering, it grows tall with up to eight see-through green flowers. These flowers have thin, dark green stripes. The flowering plants also have up to ten leaves growing along their stem.

Discovering the Greenhood Orchid

This orchid is known as a "greenhood" because of the shape of its flowers. Pterostylis macrosepala is a plant that lives on land. It is a perennial plant, meaning it lives for more than two years. It's also deciduous, which means some parts of it die back each year, but it grows again from an underground part called a tuber.

How the Plant Looks

When the plant is not flowering, it has a rosette of three to five leaves. These leaves are shaped like an egg or a spear. Each leaf is about 10 to 30 millimeters (about 0.4 to 1.2 inches) long and 5 to 10 millimeters (about 0.2 to 0.4 inches) wide. They have a small stem called a petiole that is up to 8 millimeters (about 0.3 inches) long.

When the plant is ready to flower, it doesn't have the rosette of leaves. Instead, it grows a tall flowering stem, or spike, that can be 200 to 600 millimeters (about 8 to 24 inches) high. This stem can have up to eight flowers. Along the stem, there are five to ten long, thin leaves that are 20 to 60 millimeters (about 0.8 to 2.4 inches) long and 3 to 7 millimeters (about 0.1 to 0.3 inches) wide.

The Unique Flowers

The flowers themselves are about 16 to 20 millimeters (about 0.6 to 0.8 inches) long and 10 to 12 millimeters (about 0.4 to 0.5 inches) wide. The top part of the flower, called the dorsal sepal, and the petals join together. They form a hood over the center of the flower. This hood is called the "galea." The galea is a see-through green with dark green stripes.

The side parts of the flower, called the lateral sepals, point downwards. They are 15 to 18 millimeters (about 0.6 to 0.7 inches) long and 10 to 12 millimeters (about 0.4 to 0.5 inches) wide. These two sepals are joined together for more than half their length. The lip of the flower, called the labellum, is 7 to 8 millimeters (about 0.28 to 0.31 inches) long and about 3 millimeters (about 0.12 inches) wide. It is pale green with a dark stripe down its middle.

This orchid usually flowers from July to September.

Naming the Orchid

The scientific name Pterostylis macrosepala was first given to this plant in 2010 by a scientist named Gary Backhouse. Before that, in 2006, another scientist named David Jones had described it and called it Bunochilus macrosepalus. He wrote about it in a book called Australian Orchid Research. His description was based on a plant he found in the Conimbla National Park.

What the Name Means

The second part of the name, macrosepala, tells us something about the plant. It comes from two Ancient Greek words. The word makros means "long," and the word sepalum (from New Latin) means "sepal." So, macrosepala refers to the large sepals of the flower that are joined together.

Where This Orchid Lives

This special greenhood orchid is only found in the Conimbla Range. It grows in open forests there. This means it likes areas where the trees are not too dense, allowing some sunlight to reach the forest floor.