Sacramento Mountains thistle facts for kids
Quick facts for kids Sacramento Mountains thistle |
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| Conservation status | |
| Scientific classification | |
| Genus: |
Cirsium
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| Species: |
vinaceum
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| Synonyms | |
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Carduus vinaceus Wooton & Standl. |
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Cirsium vinaceum is a rare type of thistle. It's often called the Sacramento Mountains thistle. This plant only grows in Otero County, New Mexico, in the Sacramento Mountains. It lives in six canyon systems there, spread over about 32 kilometers. This thistle is rare because it needs a special kind of mountain wetland to grow. These wetlands are naturally uncommon and are also in danger. The government officially listed this plant as threatened in 1987.
Contents
About the Sacramento Mountains Thistle
This thistle is a perennial plant, meaning it lives for more than two years. It can grow very tall, up to 200 centimeters (about 80 inches). The plant is mostly purple, especially its stems and flower clusters.
Leaves and Flowers
The leaves grow in a circle close to the ground, like a rosette. They can be up to 50 centimeters (20 inches) long. These leaves are mostly green with yellow spines along their edges.
Each strong plant grows many flower heads. These heads hang down from branches. The thistle blooms during the summer. Each flower head is about 3 to 5 centimeters wide and long. It has special leaf-like parts called phyllaries that are purple. These phyllaries curve outwards and end in hard, spiny points. Inside the head are many pinkish-purple, hair-like flowers.
Seeds and Appearance
The fruit of the thistle is a small, dry seed called an achene. It has a feathery, plum-like top called a pappus, which can be up to 2 centimeters long. This helps the seeds float away. The Sacramento Mountains thistle might look similar to the musk thistle.
Where the Thistle Lives
This plant's natural home is in streams and wet spots called seeps. These are found at high places, around 8000 feet up in the mountains. The thistles grow their roots in cracks in the travertine rock, which is a type of limestone. These cracks are filled with water, and the plants can handle being constantly wet. Sometimes, they even grow right in the streams.
Surrounding Environment
The waterways where the thistle lives are usually surrounded by open meadows. There are also forests of Douglas-fir trees nearby. Other trees in the area include Ponderosa pine, New Mexico locust, and Gambel oak. Many of these thistle groups are found inside the Lincoln National Forest.
Why the Thistle is Endangered
The Sacramento Mountains thistle is in danger because its special home is being harmed.
Environmental Threats
The thistle needs streams and seeps to survive. But sometimes, water is taken away from these places, which can destroy the thistle's home. Activities like logging (cutting down trees), road work, and outdoor fun can also damage the wet areas where the thistle grows.
Impact of Livestock
Livestock, like cows, roam over much of the area. They can seriously change the land by stepping on it and eating plants. The thistle used to grow in more places, but now it's mostly found in steep, rocky canyons where livestock can't easily reach. When animals were kept out of a sensitive area, the thistle grew much better. This showed how much livestock can affect the plant.
Competition from Other Plants
Some plant species that are not native to the area are also a problem. These include musk thistle and Fuller's teasel. They "outcompete" the native thistle, meaning they grow faster and take up space and resources. Fuller's teasel is especially harmful; it has been seen growing right in the middle of groups of Sacramento Mountains thistles.
Insect Damage
Several insects eat the thistle, especially its developing seeds in the flower heads. These insects include the gall fly Paracantha gentilis and the artichoke plume moth Platyptilia carduidactyla. The bumble flower beetle Euphoria inda and the stem borer weevil Lixus pervestitus also cause damage. Large parts of some thistle groups have been harmed by these insects.
Non-Native Weevil Threat
A non-native weevil called Rhinocyllus conicus could also harm the thistle. This weevil was brought to North America on purpose to control other types of invasive thistles that are considered noxious weeds. Luckily, this weevil was never released in New Mexico because it might attack the native Sacramento Mountains thistle. However, it has moved into the area on its own. Its spread is limited for now, but it is expected to grow. We don't know yet how much damage it will cause to the Sacramento Mountains thistle.
Thistle Population and Reproduction
When the plant was first added to the endangered species list, there were about 20 groups of plants, with up to 15,000 thistles in total. It can be tricky to count how many individual plants there are.
Seed Dispersal
This plant grows in or near water. Its seeds can float downstream, which is called aquatic seed dispersal. This means seeds drop into the water and float far away to grow new plants. What looks like many separate patches of plants along a waterway might actually be considered one large group. This is important when deciding how to protect the species.
Vegetative Reproduction
The thistle also often grows new plants without seeds, which is called vegetative reproduction. It uses underground stems called rhizomes. So, what looks like a big group of many plants might actually be just one original plant and its clones. This makes it harder to guess how much genetic diversity (variety in genes) the species has.
Protected Status Review
In 2010, experts reviewed the thistle's federal protection status. They found that there were fewer places where the plant lived, fewer groups of plants, and usually fewer individual thistles at known survey spots. Most of the same dangers that existed when the plant was first listed are still present today. Because of this, the Fish and Wildlife Service does not recommend changing the plant's protected status.
