| Cirsium arvense (L.) Scop. | |||
| |||
| Family | Compositae — APG family: Asteraceae | ||
| Synonyms | Serratula arvensis L. | ||
| Common name | canada thistle | ||
| Description | Stem unwinged, furrowed, from slender taproot with far-creeping lateral roots producing shoots; basal leaves oblong-lanceolate in outline, more or less pinnatifid, with triangular, toothed lobes ending in spines, glabrous or floccose; upper leaves more deeply pinnatifid; heads solitary or 24 together; outer involucral bracts ovate- mucronate with spreading spiny points, the inner longer, lanceolate-acuminate, with scarious tips; flowers pale purple or whitish; pappus long, brownish. | ||
| Ecology | An introduced weed. Described from Europe. |
This is a digital representation of Eric Hultén’s ‘Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants’, which was published by Stanford University Press in 1968. The book was digitized by C. Webb (at UAMN) as part of the Flora of Alaska project, with funding by the US NSF (Grant 1759964 to Ickert-Bond & Webb), and with permission of Stanford University Press. Data and images © 1968 Board of Trustees of the Leland Stanford Jr. Univ. Usage licence: Creative Commons BY-NC-SA 4.0. NB: You may find OCR errors; please refer to the hard-copy if in doubt.