This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
I. Spear Thistle (Cnicus lanceolaus, Willd.). 2. Milk Thistle (Silybum marianum, Gaertn.). 3. Chicory (Cichorium Intybus, L.). 4. Hawk's Heard (Crepis virens, L.). 5. Hound's Tongue (Cynoglossum officinale, L.). 6. Viper's Bugloss (Echium vulgare, L.).
This is one of our finest, tallest, and strongest thistles. The Spear Thistle is tall and erect in habit. The stem is erect, stout, hairy, furrowed, with strong spinous wings. The leaves are inversely egg-shaped, lance-shaped, deeply divided nearly to the base, running down the stem, white and cottony below, the lobes large, few, divided into two nearly to the base, the segments entire, lance-shaped, with stout long spines. The flower-stalk is short. The florets are purple.
Photo. B. Hanley - Spear Thistle (Cnicus Lanceolatus, Willd.)1
The flowerhead is large, not so cottony as in woolly-headed Thistle, terminal, solitary or 2-3, in groups, erect. The involucre is egg-shaped, shaggy, cottony, the phyllaries lance-shaped, awl-like, with a strong midrib, spreading, spinous, the spines long. The fruit is striped, smooth, shining. The pappus is feathery.
Spear Thistle is about 3 ft. high. Flowers are found from June to September. The plant is a deciduous herbaceous plant, biennial, propagated by seeds.
The flowerheads are much as in C. arvensis, but the honey is not so accessible. The narrow tubes of the florets and involucre are much longer (16-18 mm.), and thus have no effect on the possibility of reaching the honey; but the throat where the honey collects is much longer, and is 4-6 mm. instead of 1-1 1/2 mm. In the former, insect visitors are less varied. It is visited more particularly by long-tongued bumble bees and honey bees, butterflies, and flies, Bombus terrestris, B. agrorum, B. lapidarius, B. campestris, Megachile, Polistes gracilis, Eri-stalis tenax, and E. arbusforum, E. nemorum, Pieris brassicae, Hesperia.
1 Not improbably these radical leaves belong to the Marsh Thistle, but the photo. shows the similar rosette habit of Spear Thistle at this stage.
The pappus is feathery, and the achenes thus well adapted to wind dispersal.
This handsome Thistle is more or less a clay-loving plant growing on a clay soil, but will also subsist on sand soil or sandy loam.
It is infested by the cluster-cup fungi Puccinia hieracii, P. cardui.
Three Hymenoptera, Andrena filipes, A. denticulatus, Megachile ligniscea; Lepidoptera, Conchylis dubitana, Myelois cribrella, Gelechia acuminatella, Painted Lady (Pyrameis cardui), Catoptilia scopoliana, Cnephasia octomaculana, Argyrolepia cnicana, Xanthosetia hamana, Depressaria arenella, D. propinquella, D. Carduella, etc.; and the flies Lonchaea nigra, Cheilosia variabilis, feed upon it.
Cnicus, Tournefort, is Greek for a thistle-like plant, and the second Latin name refers to the shape of the leaves.
Names by which it is known include Bow Fistle, Bur, Cheese, Dashel, Marian, Quat Vessel (Bank, Bell, Bird, Blue, Boar, Bow, Buck, Bull, Bur, Horse, Scotch Thistle). The first name was given because goldfinches feed on the seeds. Boar Thistle refers to the strong prickles. Children blow the pappus, saying:
"Marian, Marian, what's the time of day? One o'clock, two o'clock, it's time we were away".
Essential Specific Characters:170. Cnicus lanceolatus, Willd. - Stem tall, winged, leaves hairy, lanceolate, decurrent, obovate, pinnatifid, lobes spinose, bifid, flower-heads purple, scales woolly, spreading, lanceolate, involucres ovate, pappus feathery.