Carthamus lanatus is a species of thistle known as woolly distaff thistle,[1]downy safflower[2] or saffron thistle. It is closely related to safflower (Carthamus tinctorius). This annual plant is a native of the Mediterranean Basin, but it is familiar in other places where it was introduced and has become a noxious weed, such as in parts of North America and southern Australia[3] with similar climates.
This is a spiny, glandular, woolly plant, which often seems to be covered in spiders' webs, due to its fine tangled fibers. It has a pale stem which may reach a meter in height, and rigid, pointed, very spiny leaves. The flower head has many long, sharp phyllaries that can be up to several centimeters long, and often bend backwards (recurved). The disc florets are bright yellow. One plant can produce many stems which mat together due to their spininess and form a small thicket. The fruit is an achene about half a centimeter long with many rigid pappus scales.
Invasive species in Australiaedit
In Australia the plant is commonly regarded as a pasture weed because it competes with desired plants such as pasture or crops, seeds and bracts become embedded in wool which results in lower returns to farmers, and dense infestations restrict stock access and are difficult to walk through. It is generally not considered a weed in much of Europe.[4]
Population biologyedit
Seed germination is stimulated by red light.[5] This means that germination is most likely in areas with little vegetation or pasture cover, e.g. when an area has been overgrazed. Seeds also require specific temperature cues and water, which means that most seeds germinate in Autumn (Fall). There are more C. lanatus seeds in the soil in Australian pastures than in similar French pastures, probably because there are more seed predators capable of removing seeds of this size in France than in Australia.[4] Many C. lanatus seeds are dormant (will not germinate, even in ideal conditions), and seedbanks decrease by approximately 70-74% per year if no seed is added.[6]
Weed managementedit
This plant can be controlled using a range of herbicides.[7] Several biological control options have been investigated for Australia, including classical biological control, although finding an insect or fungus that will not also attack safflower has proven difficult. A rosette-feeding fly Botanophila turcica shows some promise.[8] The potential for using pathogens already present in Australia has also been investigated.[9]
In pastures, good pasture cover in Autumn will reduce germination,[10] suggesting that pastures should be managed to reduce grazing pressure over summer, and increase the cover from summer-growing perennial grasses. Population models suggest that strategic grazing may be one of the most effective long-term control options for infested pastures.[11]
Referencesedit
^USDA, NRCS (n.d.). "Carthamus lanatus". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 11 January 2016.
^Crump et al. 1996. Australasian Plant Pathology 25:143
^Grace et al. 2002. The Rangeland Journal 24:313-325
^Grace 2001. PhD Thesis, University of New England, Australia
External linksedit
Wikimedia Commons has media related to Carthamus lanatus.
Jepson Manual Treatment
Photo gallery
January 01, 1970
carthamus, lanatus, species, thistle, known, woolly, distaff, thistle, downy, safflower, saffron, thistle, closely, related, safflower, carthamus, tinctorius, this, annual, plant, native, mediterranean, basin, familiar, other, places, where, introduced, become. Carthamus lanatus is a species of thistle known as woolly distaff thistle 1 downy safflower 2 or saffron thistle It is closely related to safflower Carthamus tinctorius This annual plant is a native of the Mediterranean Basin but it is familiar in other places where it was introduced and has become a noxious weed such as in parts of North America and southern Australia 3 with similar climates Carthamus lanatus Scientific classification Kingdom Plantae Clade Tracheophytes Clade Angiosperms Clade Eudicots Clade Asterids Order Asterales Family Asteraceae Genus Carthamus Species C lanatus Binomial name Carthamus lanatusL Synonyms Carthamus baeticus Contents 1 Description 2 Invasive species in Australia 2 1 Population biology 2 2 Weed management 3 References 4 External linksDescription editThis is a spiny glandular woolly plant which often seems to be covered in spiders webs due to its fine tangled fibers It has a pale stem which may reach a meter in height and rigid pointed very spiny leaves The flower head has many long sharp phyllaries that can be up to several centimeters long and often bend backwards recurved The disc florets are bright yellow One plant can produce many stems which mat together due to their spininess and form a small thicket The fruit is an achene about half a centimeter long with many rigid pappus scales Invasive species in Australia editIn Australia the plant is commonly regarded as a pasture weed because it competes with desired plants such as pasture or crops seeds and bracts become embedded in wool which results in lower returns to farmers and dense infestations restrict stock access and are difficult to walk through It is generally not considered a weed in much of Europe 4 Population biology edit Seed germination is stimulated by red light 5 This means that germination is most likely in areas with little vegetation or pasture cover e g when an area has been overgrazed Seeds also require specific temperature cues and water which means that most seeds germinate in Autumn Fall There are more C lanatus seeds in the soil in Australian pastures than in similar French pastures probably because there are more seed predators capable of removing seeds of this size in France than in Australia 4 Many C lanatus seeds are dormant will not germinate even in ideal conditions and seedbanks decrease by approximately 70 74 per year if no seed is added 6 Weed management edit This plant can be controlled using a range of herbicides 7 Several biological control options have been investigated for Australia including classical biological control although finding an insect or fungus that will not also attack safflower has proven difficult A rosette feeding fly Botanophila turcica shows some promise 8 The potential for using pathogens already present in Australia has also been investigated 9 In pastures good pasture cover in Autumn will reduce germination 10 suggesting that pastures should be managed to reduce grazing pressure over summer and increase the cover from summer growing perennial grasses Population models suggest that strategic grazing may be one of the most effective long term control options for infested pastures 11 References edit USDA NRCS n d Carthamus lanatus The PLANTS Database plants usda gov Greensboro North Carolina National Plant Data Team Retrieved 11 January 2016 BSBI List 2007 xls Botanical Society of Britain and Ireland Archived from the original xls on 2015 06 26 Retrieved 2014 10 17 Parsons amp Cuthbertson 1992 Noxious Weeds of Australia Inkata Melbourne a b Grace et al 2002 Proceedings 13th Australian Weeds Conference pp 529 532 Wright et al 1980 Australian Journal of Plant Physiology 7 587 594 Grace et al 2002 Australian Journal of Agricultural Research 53 1327 1334 Peirce JR 1995 Carthamus lanatus In Biology of Australian Weeds RG amp FJ Richardson pubs Melbourne Sheppard amp Vitou 2000 Acta Oecologia 21 6 1 11 Crump et al 1996 Australasian Plant Pathology 25 143 Grace et al 2002 The Rangeland Journal 24 313 325 Grace 2001 PhD Thesis University of New England AustraliaExternal links edit nbsp Wikimedia Commons has media related to Carthamus lanatus Jepson Manual Treatment Photo gallery Retrieved from https en wikipedia org w index php title Carthamus lanatus amp oldid 1182016853, wikipedia, wiki, book, books, library,
