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.
This handsome plant is found to-day and not earlier in the North Temperate Zone in Europe and West Asia. In Great Britain it occurs in the Peninsula, Channel, Thames, Anglia, and Severn provinces, and in Glamorgan, Pembroke, Cardigan, Montgomery, Carnarvon, Denbigh, Flint, and Anglesea, throughout the Severn provinces and Mersey except Mid Lancs, in the Humber and Tyne provinces, and in Westmorland, Dumfries, Wigtown, Ayr, Renfrew, Lanark, Dumbarton, and Clyde Isles. In England and Ireland it is rare, and local in Scotland.
The Common Teasel is a conspicuous plant, growing in clumps by the side of the road upon the rising banks of some ditch just under the hedge, because it prefers the moist side of some stream along the banks of which it forms a long line as if for protection with its bristling heads of bloom. It is usually exterminated by farmers, hence this linear arrangement. The Teasel is erect in habit. The plant is hairless, and the stem is stout, rigid, with prickly ribs, leafy, branched. The leaves are opposite, simple, inversely egg-shaped to lance-shaped, stalkless. The radical leaves of the first year are spreading. The stem-leaves are oblong to lance-shaped, entire, scalloped, with a prickly midrib, united below.1
The flowerheads are large, conical, oblong. The florets are pale lilac. Each floret has a separate bract and an involucre. The ascending slender involucre overtops the flowerhead with upwardly curved bracts. The calyx limb is not persistent. The corolla tube is unequally 4-lobed with 4 stamens. The scales of the receptacle are straight and exceed the florets. The floral bracts are long, rigid, awllike, fringed with hairs. The partial involucre or involucel is downy. The fruit is 4-sided with 8 depressions.
Forming a head of numerous florets the flowerhead is conspicuous. The anthers ripen first. The corolla tube is narrow, 9 - 11 mm. long. One of the branches of the style is wanting or nearly so, for the tube is not wide enough for an insect to insert its head if there were two stigmas. The inner surface of the stigma is covered with papilla;. The floral bracts overtop the anthers and stigmas, and insects do not touch the last with the ventral surface in creeping over the flower, but with the head when inserting the proboscis. Hence it is of advantage that the second stigma is rudimentary, as if both were present the inner surfaces, which alone are receptive, might not be rubbed by the bee in its effort to penetrate the tube. Honey is secreted in the upper part of the ovary, and the corolla tube by its length helps to contain and conceal it. The divisions get into each other's way, an instance in which nature can afford to improve the present arrangement.
1 Water collects in the axils, and insects drowned in it are absorbed, and thus small flies do not reach the flowers and rob them of honey. The water serves as a reservoir, and is of use to the plant in dry seasons.
Photo. Flatters & Garnett - Teasel (dipsacus Sylvestris, Huds.)
The Teasel is visited by Bombus rupestris, B. lapidarius, B. agrorum.
The fruits are provided with a parachute arrangement which aids in wind-dispersal, in the form of persistent bracts or leaf-like organs.
The Teasel is a sand-loving plant growing on a sand soil, but requires also some proportion of humus.
Only moths feed on it, as the Burnished Brass Plusia chrysitis, Square-spot Rustic Agrotis xanthographa, Eupcecilia roseana, Auti-thena Gentianana.
Dipsacus, Dioscorides, is from the Greek dipsao, I thirst, because of the water collected in the base of the leaves. Teasel is from A.S. tcesan, from its use in teasing wool. The second name denotes a woodland habitat.
It is called Adam's Flannel, Barber's Brushes, Brushes, Sweep's Brushes, Card Teazel, Card Thistle, Churchbrooms, Gipsy's Combs, Pricky Back, Tazzel, Teasel, Venus Bath or Basin. The last name is explained thus by Lyte: " It is termed Labrum Veneris and Laver Lavacrum of the forme of the leaves, made up in fashion of a bason, which is never without water." The name Carde Thistle is explained by Gerarde thus: " In some of our Northern Counties large quantities of the Teazel are planted that there heads may be used in Carding wool ". This may refer to the Fuller's Teazel.
It was named Church Brooms from the resemblance of the flower-heads in shape to the long " turk's head brooms used for sweeping high places ".
" Tezils or Fuller's thistle, being gathered and hanged up in house, where the air may come freely to it, upon the alteration of cold and windy weather will grow smoother and against rain will close up its prickles."
In the old days it was held to have healing virtues, the water caught up in the connate leaf-base being said to be good for bad eyesight, and called virga pastoris in Chaucer's day. It formed part of the remedy " Save " also.
Essential Specific Characters: 147. Dipsacus sylvestris, Huds. - Stem tall, stout, erect, prickly, leaves prickly along the midrib, lanceolate, connate, opposite, flowers lilac, scales of receptacle straight, longer than flowers, involucres curved upwards.