- Author: Guy B Kyser
This is part of a talk I gave last week in Marin County. These three annual thistles turn up everywhere in northern California, so it's nice to know them by name. They're mostly on disturbed sites, roadsides, and waste ground, but they can also establish on rangeland, pasture, and natural areas.They germinate and grow into rosettes during winter, then in spring they bolt and produce purple flowers.
Like a lot of our weeds, these species originated in southern Europe, southwestern Asia, and the Middle East. They 'learned' how to survive alongside human agriculture early on. |
Italian thistle (Carduus pycnocephalus) is probably the most common. It is a slender plant with sparse foliage, up to 6 ft tall on fertile soils. Its stems have spiny wings and its flowers are small and cylindrical. The leaves are deeply lobed and have a little bit of milky striping. Italian thistle also has several close relatives in California.
Milk thistle (Silybum marianum) can look a lot like Italian thistle, especially as a seedling. But its leaves are not as deeply lobed, the milky stripes are much more pronounced, and the plant grows much bigger and more robust. The flowers are larger and more globe-shaped. The stems don't have wings like Italian thistle.
Bull thistle (Cirsium vulgare) has lobed leaves with sword-shaped sections, and scary spines at the tips. This thistle doesn't have the milky striping, and its leaves are hairier than Italian or milk thistle. It has spiny-winged stems, and its flowers are classic onion-shaped thistle flowers. This plant often grows as a biennial.
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If anyone would like to harvest a huge crop of them, I can show you where they grow abundantly in Milam County Texas.
As far as I know, the answer is No... the leaves can't form new roots once they're cut from the plant. However, if you cut off a milk thistle at the base, leaving the root in the ground, the root can sometimes develop a new shoot.
Is it safe for goats or lambs to eat the leaves after they've wilted post glcosphate application?
As to glyphosate & grazing, there aren't any grazing restrictions following use of glyphosate... however, if the critters are going to eat a lot of the foliage, my preference would be to wait until after rain or irrigation so they don't ingest too much of the soapy surfactant.
Sorry for the slow response - busy season -
I'm going to suggest you show this plant to a farm advisor. Since I don't know for sure what the plant is, I would use caution.
Sorry. Is there any way to share an image? Low growing. Thistle with no stem.