PAWSON : THE POSITION OF ANNUALS. 3 
return home; the little speedwells and geraniums would be sent 
back to the rocks ; the clans Zamium, Galeopsis, and Fumaria would 
disappear, and the strong tribes Chenopodium, Atriplex, and Poly- 
gonum would lose half their numbers. 
Of nettles we have two common species, one perennial and one 
annual. The perennial plant grows strongly amongst other vegeta- 
tion wherever it establishes itself, while the annual (Urtica urens) 
villages. Of dog’s mercury also we have two sorts. The perennial 
is one of the most aggressive plants in our flora, often in shady 
positions destroying all other herbage ; the annual, although it grows 
large and branching, can survive only in cultivated ground. 
I was led by these reflections to examine the list of our British 
plants to see more exactly what position the annuals and biennials 
hold among their fellows. The number of our flowering plants may 
be taken at 1,800 species, which-is probably as many as would be 
allowed by most botanists. Some 300 of these are annual, and 
about 60 biennial: a fifth of the whole, therefore, is monocarpic. 
Of the 300 annuals, at least 70 are practically confined to cornfields 
and cultivated ground (this list includes most of the aliens and 
4 colonists); 20 are sea-shore plants or inhabiting brackish mud-flats ; 
and waysides, and on dry sandy ground; nearly 20 more are para- 
sites, feeding on perennial plants. 
Of the 50 or 60 species which remain, and which form an 
inconsiderable part of our flora, some are very uncommon, and 
there are very few indeed which can be found ordinarily growing 
in perennial herbage. Among these, Linum catharticum is con- 
spicuous, and the three annual gentians and the nearly-allied 
common centaury. These are all found in pastures where the 
ground is well covered by grasses. Their roots are small, and 
their position is similar to that of the semi-parasitic Zuphrasia. 
Can these be also dependent on perennials ? 
The annual vetches and Corydalis claviculata and Galium aparine 
do not shun crowded ground ; they choose bushy places and spring 
up in the dark among briars and brambles ; by means of tendrils or 
hooks they climb out into the sunshine, and thus flourish where 
most vegetation would be choked. 
Biennial herbs link together the annual and the perennial, 
for some of them, if they are sown early, will often flower and 
die in the same year; yet others will occasionally, as the foxglove, 
by means of offsets, prolong their life beyond two years. Again, 
January 1897. 
