Rancid spider orchid facts for kids

The Caladenia saxatilis is a special kind of plant. It belongs to the orchid family, which is called Orchidaceae. This orchid is found only in South Australia, meaning it is endemic there. It grows in the ground and has a single leaf that feels a bit hairy. Its flowers are usually a pale creamy-green color. Sometimes, you might see thin reddish lines on them. You can find this unique orchid in the southern part of the Flinders Ranges.

What the Rancid Spider Orchid Looks Like

The Caladenia saxatilis is a plant that lives for many years. It grows from an underground tuber, which is like a small storage root. Every year, it loses its leaves and then grows new ones. It's a herb, meaning it has soft, green stems, not woody ones like trees.

It has one bright green leaf that is shaped like a narrow spear. This leaf can be about 10 to 15 centimeters (4 to 6 inches) long and 0.5 to 1.4 centimeters (0.2 to 0.5 inches) wide. You might notice some red spots near the bottom of the leaf. Both the leaf and the flower stem are covered in tiny, clear hairs. These hairs can be up to 3 millimeters (0.1 inches) long.

The orchid usually has one or two pale creamy-green flowers. Each flower is about 4.5 to 5.5 centimeters (1.8 to 2.2 inches) wide. They grow on a thin, strong stem that can be 20 to 35 centimeters (8 to 14 inches) tall.

Each flower has different parts:

• The top petal, called the dorsal sepal, is about 3.5 to 4 centimeters (1.4 to 1.6 inches) long. It's wider at the bottom and then gets thinner, ending in a sticky tip.
• The two side petals, called lateral sepals, are also about 3.5 to 4 centimeters (1.4 to 1.6 inches) long. They are wider at their base and then narrow down to sticky tips.
• The other two petals are about 2.7 to 3.3 centimeters (1.1 to 1.3 inches) long. They are spear-shaped at the bottom and become very thin.
• The labellum is the special lip-like petal of the orchid. It's shaped like a spear or an egg, about 1.4 to 1.6 centimeters (0.6 inches) long. Its edges have 7 to 10 pairs of tiny, thin teeth. The very tip of the labellum curls downwards. There are also four to six rows of dark red bumps, called calli, along the middle of the labellum.

This beautiful orchid usually blooms in August and September.

How the Rancid Spider Orchid Got Its Name

The Caladenia saxatilis was first officially described in 2006. A botanist named David Jones gave it the name Arachnorchis saxatilis. He wrote about it in a scientific book called Australian Orchid Research. He found the first plant near the Mount Remarkable National Park.

Later, in 2010, another botanist, Robert Bates, changed its name to Caladenia saxatilis. The second part of its name, saxatilis, comes from a Latin word. It means "among rocks." This name was chosen because this orchid often grows in rocky places.

Where the Rancid Spider Orchid Lives

This special spider orchid grows in several areas of South Australia. You can find it in the Flinders Ranges, the Northern Lofty region, the Murray region, and the Yorke Peninsula. It likes to grow among rocks in tall forests.