26 report — 1859. 



appear to be unusually dark in colour, in which it contrasts finely with the 

 following. 



Plot K. Datura Stramonium, American Thorn-Apple. — Only three plants 

 have this year arrived at maturity, but its extreme whiteness is quite re- 

 markable when placed beside the D. Tatula, a crop, which, it will be remem- 

 bered, was formerly reported as being almost destitute of colour. 



Plot L. Dipsacus sylveslris (L.) 1 mixe( j # 

 „ fullonum (L.) / 



These, though distinguished by Linnaeus and retained as species by Smith 

 and Hooker, are shoivn by my garden experiments to be but varieties; in- 

 deed, Sir W. Hooker, in speaking of the reflexed scales, says, " These hooks 

 become obsolete by long cultivation in poor soil, and there is reason to 

 believe that D. fullonum is but a variety of D. sylvestris." In this he has 

 been followed by other authors ; as yet I am not aware of any direct obser- 

 vations upon the point, but my experiments upon the two forms enable me 

 to supply this. 



In 1857 I had a plot each of Dipsacus sylvestris and D. fullonum flower- 

 ing, and at last ripening their seed side by side. This seed became scat- 

 tered about the garden, and not having a distinct plot of teasels for botanical 

 illustration, a plot was made of the most vigorous plants which could be 

 selected from the self-sown examples without an attempt to discriminate the 

 different sorts, which indeed would have been impossible at this stage of 

 growth. Now the result at the time of my writing is very striking ; there 

 are the true D. sylvestris with the straight scales, the D. fullonum with the 

 stiff reflexed hooks, and all intermediate stages, so that it is most difficult to 

 separate them, if indeed they are to be distinguished. In order, therefore, 

 to keep up the fulling apparatus of the teasel in perfection, it is important 

 that the plants be cultivated, as, letting them go wild, they revert to the use- 

 less form ; and strong land is also necessary to the growth of stiff hooks. 



Plot M. Carduus tuberosus. — This plant, which I was fortunate enough to 

 discover in North Wilts, about the Avebury Circles, is the same as was 

 recorded some five-and-twenty years since, as existing at Great Ridge in the 

 south of that county, It has for a long time been lost to our flora, though a 

 few specimens were still in cultivation in the garden of my friend Mr. Cun- 

 nington of Devizes. 



In August 1857 I brought home a few plants from Avebury, which made 

 some new shoots last year, but did not flower; they, however, had the cha- 

 racteristic tubers of a good size. These were parted, and now occupy the 

 plot as above. 



As now seen in their wild habitat, the flower-stem is scarcely above a foot 

 high, with from two to four flowers each. In cultivation it has attained the 

 height of 3 feet, with a large mass of stems to each plant, bearing from six to 

 twelve flower- heads each: the flowers are very showy, and, like the tubers, 

 increase in size under cultivation. As this plant yields these tubers so 

 abundantly, I boiled some of them to ascertain if they were edible ; and as 

 they are made up of feculent matter which proves to be tender and sweet to 

 the taste, I am not quite sure that this thistle might not be cultivated as a 

 vegetable to advantage. 



Seeds of the plant have been saved for the purpose of experiment, as I 

 have not yet given up the idea of the hybridity of the Carduus tuberosus; 

 and, with all its large flowers, I may observe that it seeds only sparingly. 



Plot N. Carduus acaulis. — By the side of the above are two varieties of 

 this plant occupying the same plot ; one the normal stemless form, another 

 with stems as much as 2 feet high, each of which bears from four to eight 



