Arnica discoidea facts for kids
Quick facts for kids Arnica discoidea |
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| Scientific classification | |
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Arnica
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| Species: |
discoidea
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Arnica discoidea is a type of arnica plant found in North America. People often call it rayless arnica. This name comes from its unique flowers. Unlike many other plants in the sunflower family, its flower heads have only small, central flowers called disc florets. They do not have the larger, petal-like flowers called ray florets that you see on a typical sunflower.
This plant grows naturally in the western United States. You can find it in states like Washington, Oregon, California, and parts of western Nevada. It likes to live in woodlands, forests, and areas with chaparral, which are dry shrublands.
Contents
What Does Rayless Arnica Look Like?
Plant Structure and Size
Arnica discoidea is a perennial herb. This means it lives for more than two years. It grows from underground stems called rhizomes. These rhizomes help the plant spread.
The plant produces a stem that can grow from about 20 to 60 centimeters tall. That's roughly the height of a ruler to two rulers stacked together. The stem is usually covered in fine hairs and small glands.
Leaves and Flowers
The lower part of the stem has several pairs of leaves. These leaves are shaped like an oval or a spade. They have small teeth along their edges. Each leaf sits on a long stalk called a petiole.
The plant's flowers grow in groups called an inflorescence. Each group has a few to many individual flower heads. These heads are also covered with tiny, sticky hairs from glands.
Each flower head contains only the small, central disc florets. However, some of the florets around the edge can grow larger. This can make them look a bit like the ray florets you see on other sunflowers. This can sometimes make it tricky to identify the plant just by looking at its flowers!
Fruits of the Plant
After the flowers bloom, the plant produces small fruits. These fruits are called achenes. An achene is a dry fruit that contains one seed.
The achenes of Arnica discoidea are about 7 millimeters long. This measurement does not include the fluffy, light-colored hairs attached to them. These hairs are called a pappus. The pappus helps the seeds float away in the wind, spreading the plant to new places.
