| Cirsium longistylum | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Cirsium |
| Species: | C. longistylum |
| Binomial name | |
| Cirsium longistylum R.J.Moore & Frankton | |
Cirsium longistylum, the long-style thistle, is a North American species of plants in the thistle tribe within the sunflower family. The species is found only in the central part of the State of Montana in the United States, in the portions of the Rocky Mountains called the Big Belt, Castle, Elkhorn, and Little Belt ranges. [1] [2]
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.
The Cynareae are a tribe of flowering plants in the daisy family (Asteraceae) and the subfamily Carduoideae. Most of them are commonly known as thistles; four of the best known genera are Carduus, Cynara, Cirsium, and Onopordum.
Asteraceae or Compositae is a very large and widespread family of flowering plants (Angiospermae).
Cirsium longistylum is a biennial or perennial herb up to 150 cm (60 inches or 5 feet) tall, with a large taproot. Leaves are up to 30 cm (26 inches) long with thin, green on the upper side but gray to white on the underside because of numerous woolly hairs; spines along the edges of the leaves. There are a few flower heads, each head with white disc florets but no ray florets. The name of the species refers to the long white styles that stick out of the florets, much longer than the corollas. [1] [3]
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year, the plant grows leaves, stems, and roots, then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming a rosette. Many biennials require a cold treatment, or vernalization, before they will flower. During the next spring or summer, the stem of the biennial plant elongates greatly, or "bolts". The plant then flowers, producing fruits and seeds before it finally dies. There are far fewer biennials than either perennial plants or annual plants.
A perennial plant or simply perennial is a plant that lives more than two years. Some sources cite perennial plants being plants that live more than three years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials.
A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot is a storage organ so well developed that it has been cultivated as a vegetable.
