Spear Thistle (Cirisium vulgare) Growing among roadside vegetation in Speyside Scotland. SCO 8469.
The inflorescence is –5 cm diameter, pink-purple, with all the florets of similar form (no division into disc and ray florets). The seeds are 5 mm long, with a downy pappus, which assists in wind dispersal. As in other species of Cirsium (but unlike species in the related genus Carduus), the pappus hairs are feathery with fine side hairs. Spear Thistle is often a ruderal species, colonising bare disturbed ground, but also persists well on heavily grazed land as it is unpalatable to most grazing animals. The flowers are a rich nectar source used by numerous pollinating insects, including Honey bees, Wool-carder bees, and many butterflies. The seeds are eaten by Goldfinches, Linnets and Greenfinches. The seeds are dispersed by wind, mud, water, and possibly also by ants; they do not show significant long-term dormancy, most germinating soon after dispersal and only a few lasting up to four years in the soil seed bank. Seed is also often spread by human activity such as hay bales. Spear Thistle is designated an "injurious weed" under the UK Weeds Act 1959, and a noxious weed in Australia and in nine US states. Spread is only by seed, not by root fragments as in the related Creeping Thistle C. arvense. It is best cleared from land by hoeing and deep cutting of the taproot before seeds mature; regular cultivation also prevents its establishment. Kingdom: Plantae (unranked): Angiosperms (unranked): Eudicots (unranked): Asterids Order: Asterales Family: Asteraceae Subfamily: Carduoideae Tribe: Cynareae Genus: Cirsium Species: C. vulgare
Size: 6063px × 4035px
Location: Newtonmore, Badenoch and Strathspey, Inverness-shire, Highland Region.
Photo credit: © David Gowans / Alamy / Afripics
License: Licensed
Model Released: No
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