Dark greenhood facts for kids

The dark greenhood (scientific name: Pterostylis nigricans) is a special type of orchid. It grows only in eastern Australia. Like many orchids, its look changes depending on whether it's flowering or not. When it's not flowering, it has a group of leaves shaped like a circle, called a rosette. But when it's ready to bloom, it grows a tall stem with up to six tiny flowers. These flowers are green, white, and brown, and they feel a bit rough.

What Does the Dark Greenhood Look Like?

The dark greenhood is a plant that grows from an underground tuber (like a small potato). It lives for many years (perennial) and loses its leaves in some seasons (deciduous). When it's not flowering, it has a rosette of three to eleven leaves. These leaves are shaped like an egg or a heart. Each leaf is about 5 to 30 millimeters (0.2 to 1.2 inches) long. They are also about 4 to 10 millimeters (0.16 to 0.4 inches) wide. Each leaf has a short stem, called a petiole, about 3 to 5 millimeters (0.12 to 0.2 inches) long.

When the plant flowers, it grows a stem that can be 100 to 350 millimeters (4 to 14 inches) tall. This stem can have up to six flowers. The flowers are spaced out along the stem. They are about 9 to 10 millimeters (0.35 to 0.39 inches) long and 4 to 5 millimeters (0.16 to 0.20 inches) wide. The flowers are green and white. They have a dark chocolate-brown tip and feel rough.

Flower Parts

The top part of the flower is called the "galea" or hood. It's made from two parts joined together: the dorsal sepal (a leaf-like part) and the petals. This hood covers the central part of the flower, called the column. The dorsal sepal curves forward and has a short point.

The two side sepals are called lateral sepals. They stand upright and stay close to the galea. They have thin, thread-like tips about 3 millimeters (0.12 inches) long. These tips do not stick out above the galea. The space between the bases of the lateral sepals is called the sinus. This sinus almost closes the front of the flower. It has a small notch in its center.

Inside the flower, there is a special lip-like petal called the labellum. It is about 4 millimeters (0.16 inches) long and 1 millimeter (0.04 inches) wide. You usually cannot see the labellum from outside the flower. Dark greenhoods usually flower between March and May.

How Was it Named?

The dark greenhood was officially described in 1988. Two scientists, David Jones and Mark Clements, gave it its scientific name. They found a sample of the plant on Stradbroke Island. The description was then published in a science journal called Austrobaileya.

The second part of its scientific name, nigricans, is a Latin word. It means "blackish." This name was chosen because of the dark color of the flowers' tips.

Where Does it Grow?

The dark greenhood grows in forests, scrublands, and heathlands. You can find it in areas near the coast in southeastern Queensland. It also grows in New South Wales, north of Evans Head.