SALSIFY (Tragopogon dubius) скачать в хорошем качестве

SALSIFY (Tragopogon dubius)

How to identify Western Salsify (Tragopogon dubius) This is a weed in the sunflower family Asteraceae, Western salsify (Tragopogon dubius). Like other weeds in this family, salsify originates mainly from Eurasia, and has become very common throughout almost all of North America. This is usually a biennial plant, though it may occasionally grow annually or as a perennial. This weed grows rapidly throughout the spring, and will bloom continuously from mid spring through the summer. Salsify grows as a single stem which usually branches in its upper half. Each branch of the stem is topped with a single flower head. The stems are smooth and hairless, and are green or slightly brown. Young plants in their first year will form basal rosettes that resemble grass. The leaves of salsify are very grass-like, being long, thin, and totally smooth and hairless. The leaves are a light, pale green in color, and gradually taper to a sharp point. The base of the leaves where they connect with the stem is often purple in color. The flowers are about ¾ to 2.5 inches across, and are yellow in color. The green bracts of the flowers are often longer than the petals themselves. The flowers will close up during the afternoon and reopen in the morning. After the flower has been pollinated, it forms a very distinct seed-head, much like a giant dandelion, with parachuted seeds 1.5 inches long. The plant only reproduces via seed. Salsify grows off of a large, deep taproot, and the entire plant is filled with a white, milky sap that contains latex. Breaking off any part of the plant will cause this sap to ooze out. There are several species of Tragopogon that live in north America, though most are very similar and not easily distinguished. Tragopogon dubius is the most common species in NA, while purple salsify, Tragopogon porrifolius is also common and can be distinguished by its purple flowers. Meadow Slasify, T. pratensis, is nearly identical to dubius, but has flower bracts shorter than its petals. All common species will frequently hybridize with each other. Sources: Weeds of the West, 5th Edition (1991) by Tom D. Whitson, published by the Western Society of Weed Science University of California Agriculture and Natural Resources IPM – Weed Gallery http://ipm.ucanr.edu/ United States Department of Agriculture – Plant Database https://plants.usda.gov