Spear thistle |
Inflorescence,
flower head, involucre, infructescence,
upper and lower leaf
surface of
Cirsium
vulgare.
On the upper leaf surface are prickly bristles.
| Cirsium vulgare (Savi.) Ten.: | |
| Blooming period: | July–August |
| Height: | 50–200 cm, rarely up to 300 cm |
| Flowers: | in heads, Ø of the heads 25–40 mm, stamens: 5, styles: 1 |
| Ray florets: | missing |
| Disc florets: | purple |
| Calyx: | transformed into a pappus |
| Stem leaves | alternate, deeply pinnatifid, lobes ending in long thorns, rough spiny serrated |
| Basal leaves: | 15–40 cm long, petiole winged or narrowing. Sometimes missing at the flowering season |
Plant biennial, herbaceous, with long, vertical taproot.
Stem erect to ascending, branched in the upper part, thorny winged, sparsely long-hairy, in the upper part often tomentose.
Stem leaves alternate, decurrent, deeply pinnatifid with irregular lobes, which culminate in long thorny spikes, sometimes only spiny serrated. Lower surface tomentose or with woolly hairs, upper side with spines or bristles.
Lower leaves large, elliptical to oblong, pinnatifid, sometimes short-stalked. Leaves decreasing in size towards the top, sessile. Leaves in the upper part often lobed deeper.
Flower heads solitary or collectively in racemose, corymbose or paniculate inflorescences. Heads in the flowering season on about 6 cm long, leafless and thorny winged stems. Receptacle flat and bristly.
The phyllaries are arranged imbricated in 10–12 rows. The outer and middle phyllaries are lanceolate to linear, spreading and mucronate. The inner ones are upright and acuminate. Phyllaries loosely cobwebby. Involucre ovoid to bell-shaped.
The flower head consists entirely of purple or rarely white tubular flowers, which are filiform, 25–35 mm long, hermaphrodite and 5-lobed, at the base without chaffy leaves.
After pollination by bees, bumblebees, beetles or butterflies, an approximately 4 mm forms long nut fruit (achene) is formed, which is light brown and slightly flattened. At the apex with 20-30 mm long, feathery, white sailing hairs.
Cirsium vulgare may form bastards with C. oleraceum, C. eriophorum, C. palustre and C. arvense.
| Floral formula: |
| * K=pappus [C(5) A5(connate)] G(2) inferior |
Occurrence:
Waysides
and
roadsides, ruderal areas. Prefers bright, slightly warm, slightly damp,
slightly alkaline and very nitrogen-rich locations.
Distribution:
Originally
Eurasia, introduced in North America and Australia.