208 On the finding of Carduus tuberosus at Avebury. 
two or three specimens thus handed down are now in Mr. William 
Cunnington’s possession, and upon paying him a visit at Devizes 
on our way from Avebury to Stonehenge, I was gratified to see a 
specimen in full flower in his garden, as well as two dried examples 
in his Herbarium; and from an examination of these, I am enabled 
to declare their complete identity with those I had so recently 
gathered at Avebury. 
Here then we have a curious example of a plant having been lost 
for many years in one locality, yet subsequently occurring in 
another: and though the collecting botanist may perhaps feli- 
citate us upon restoring this to the British Flora, I have myself 
great hesitation in receiving it as a true and undoubted species: 
the grounds for which I would shortly sum up as follows. It occurs 
sparingly at Avebury, surrounded by the true “ Carduus acaulis” 
(Linn.), and “C. acanthoides” (Linn.), in great abundance. Its most 
important distinctive character will be found in the radical tubers, 
which in full grown examples are somewhat large and fleshy, and 
unilaterally placed on the rhizome. In smaller specimens the 
roots are long and flexile, but not expanded into tubers, which is 
just the state in which they occur in the “ Carduus acaulis’’ (Linn.) 
It is true that it cannot be described as acauline as the stem is 
more than a foot in height, but this is also often the case with the 
true “C. acaulis” (Linn.), as we have now before us examples of 
this species several inches high. 
From these circumstances in connection with the rarity of the 
tuberous form in a plant that seeds so abundantly, each head of 
flowers being capable of perfecting as many as one hundred and 
fifty seeds; taking also in consideration the well known sporting 
propensity of this genus, I cannot help thinking this to be a hybrid, 
and from the fact of the abundance of the two forms before indi- 
cated in its immediate vicinity, we may not unreasonably look 
upon them as the origin of our tuberous type. There is perhaps 
no genus of plants more perplexing to the botanist than that of 
“ Qarduus,”’ which is now made to include Cnicus, and hence the 
variation in the number of species in our different floras, and thus 
Babington heads his descriptions of them with the following signi- 
