Pterostylis tristis facts for kids

The midget greenhood (scientific name: Pterostylis tristis) is a special type of orchid found only in New Zealand. It's called a "greenhood" because of the shape of its flowers. Both young and mature plants have a group of thick leaves that lie flat on the ground. When the plant flowers, it can have up to eight yellowish-green or brownish flowers with light stripes.

What Does the Midget Greenhood Look Like?

The midget greenhood is a plant that grows on land. It's a perennial plant, which means it lives for more than two years. It's also deciduous, so it loses its leaves at certain times of the year. This plant is a herb, meaning it has soft stems, not woody ones like a tree. It grows from an underground tuber, which is like a small, swollen root that stores food.

Non-flowering plants have a group of five to seven brownish or yellowish-green leaves. These leaves grow on a stalk and form a rosette, which is a circular pattern, lying flat on the ground. Each leaf is about 5 to 15 millimeters (0.2 to 0.6 inches) long and 3 to 10 millimeters (0.1 to 0.4 inches) wide.

When the plant flowers, it grows a fleshy stem that is 20 to 100 millimeters (0.8 to 3.9 inches) tall. This stem can hold up to eight yellowish-green or brownish flowers with stripes. The leaves that form the rosette usually dry up and disappear by the time the plant flowers.

Parts of the Flower

The flower has some unique parts:

• The dorsal sepal (the top part of the flower) and the petals (the inner parts) are joined together. They form a hood, which is called a "galea." This hood covers the column, which is the central part of the orchid flower.
• The galea is about 5 to 10 millimeters (0.2 to 0.4 inches) long and wide. The dorsal sepal is a little longer than the petals.
• The lateral sepals (the side parts of the flower) point downwards. They are mostly joined together, and each one has a short point at its end.
• The labellum (the orchid's special lip petal) is short, wide, and has a rounded end. It has a smooth, small lobe (a rounded part) on its upper end.

Midget greenhoods usually flower between September and January.

How Did It Get Its Name?

The midget greenhood was first officially described in 1886 by a person named William Colenso. He found a sample of the plant on the south bank of the Waipawa River. His description was then published in a scientific journal called Transactions and Proceedings of the New Zealand Institute.

The scientific name for the species, tristis, comes from a Latin word that means "sad." William Colenso himself described the first plant he found as "very small, rather dingy-looking." This might be why he chose the name "tristis."

Where Does the Midget Greenhood Live?

The midget greenhood usually grows in open areas with tussock grassland. Tussock grassland is a type of natural grassland with clumps of grass.

You can find this orchid on the South Island of New Zealand. It grows east of the main mountain ranges, starting from the Canterbury area and going south. There are also a few old records that suggest it might have once grown on the North Island and Stewart Island, but it's mainly found on the South Island now.