THE TIIAMES-SIHE BRASSICA 
105 
Thames in Surrey. Watson writes: ‘My conviction is, on a fami¬ 
liarity with the plant during thirty years, that the Thames-side 
Brassica is simply the wild stock of the true turnip/ ‘ As we see [the 
species] by the Thames side the seeds germinate and become plants 
early in [the] autumn. These live through the winter and flower in 
the succeeding spring or summer. They have a tuft of green and 
rough radical leaves, which are more lyrate-pinnatifid than the leaves 
of the annual form [B. campestris], As the flowering stem rises 
from this winter tuft in the following spring,’ the leaves produced on 
it are smooth, and become glaucous in hue, especially upwards. The 
plant as 1 have taken it along the Thames has a hard woody taproot 
sometimes thicker than the stem. I follow Watson in supposing that 
it represents a feral form of the turnip species, but I should call 
it Brassica Rapa , with which its foliage also more closely identifies 
it. Watson calls it B. campestris, using the name inclusively, but 1 
prefer, for purposes of identification, to keep the names and the 
plants distinct. Whether the plant represents an aboriginal form 
from which the cultivated turnip is derived or a run-wild race of the 
turnip, I am unable to say. The fact that it has persisted through 
so many years raises doubt whether it is merely a run-wild turnip, 
and the fact that it so long remains as a biennial indicates that it is 
not merely an incidental form of B. campestris. It may be signifi¬ 
cant that Linnaeus, who marks B. Rapa as biennial, assigns it to 
‘ habitat in arvis Angliae, Belgii ’: did he know such a feral or spon¬ 
taneous plan! ? I have seen nothing like this Thames-side plant in 
North America, but I have taken it, with woody root, on the island 
of Barbados: if the cultivated turnip runs wild and persists, we 
should expect its deliverance to occur in this country as well as else¬ 
where : material is needed ” (p. 86). 
CRYPTOGAMS FROM THE ANTARCTIC. 
Bt 0. Y. Darbishire. 
(The University, Bristol.) 
These Cryptogams were collected on the British Antarctic Ex¬ 
pedition 1907-1909 and on the expedition of 1914-1917, both led by 
the late Sir Ernest Shackleton. 
The Lichens comprise fifteen species which could be satisfactorily 
named, among which there was one new species, Buellia pernigra , 
of which a description is subjoined. Including this the total number 
of lichens known from the Antarctic Continent is now 209. The 
species enumerated were all collected on the slopes of Mount Erebus 
(South Victoria Land), except two gathered on Elephant Island. An 
asterisk indicates a new locality:— 
1. Rhizocarpon qeoqraphicum (L.) DC. Mount Erebus. 
2. Qyropliora anthracina (Wulf.) Kbr. Mount Erebus. 
*3. Gyrophora vellea (Linn.) Acli. Elephant Island. 
4. Rlacodium elegans (Link.) Nyl. Mount Erebus. 
*5. Rlacodium miniatum Hffm. Mount Erebus. 
6. Caloplaca citrina (Hffm.) Th. Fr. Mount Erebus. 
