Ridley .— The Distribution of Plants. 13 
with very small white flowers, and small capsules of very small seeds. It 
was described by Linne from Jamaica specimens in 1753, and is undoubtedly 
a plant of South American origin. It is now abundant all over Africa, 
South America, and the Malay Peninsula and Archipelago. A note by 
J. Rotheram in a copy of Linne’s ‘ Species Plantarum ’, ed. 2,1762, states that 
it was used as a remedy for venereal disease in Africa. It is recorded for 
the Congo in Tuckey’s voyage in 1816 by Christopher Smith. Loureiro 
met with it in Cochin China in 1773, and Robert Brown found it in 
Australia in 1802. It first appeared in India at Serampore in 1845, but it 
is very scarce there to the present day and has never been met with in 
Ceylon. 
My earliest record in the Malay Peninsula is 1884, but it was probably 
there before. It has since travelled farther in Pahang and other parts than 
any South American weed except perhaps the grass, Paspalum conjugatum. 
Wherever buffaloes or cattle go, this plant follows, and it is frequently to be 
seen springing up from the dung of these animals, which readily feeds on it. 
Besides a reputation as a drug in venereal disease, it is also considered 
beneficial in consumption. The Malaya call it Te’Macao (Macao Tea), 
which implies that they consider it as having been derived from China. 
I would suggest its having been carried about at first as a drug, prob¬ 
ably dried whole, capsules and all, and by this means got from the West 
Indies to Africa and to the Philippines. There is nothing to show it was 
ever cultivated. From these places it has spread, mainly in cattle fodder, 
to the Malay Islands and Peninsula as far north as Siam, in fact wherever the 
Malay buffalo and cattle are sent. Its absence from Ceylon, and largely from 
India and Polynesia, is due to the fact that there has never been a cattle 
trade between these countries and the Malay or African regions. 
This is a good sample of the wide distribution of a plant, extremely 
abundant in its area, which has obtained marked extension in a very short 
period of time, viz. about 200 years. 
By way of comparison as to the difference in rapidity and wideness 
of distribution of species, I will give an illustration from two English 
weeds, both Compositae, Galinsoga parviflora , Cav., and Matricaria 
discoidea , DC. They are both herbs of American origin. 
Galinsoga parviflora , Cav., occurred in Spain as early as 1794, and 
has since appeared in Holland, Germany (Berlin, 1812), Italy, and 
Austria, more or less sporadically and apparently chiefly as an escape 
from botanic gardens. In England the earliest record is at Twickenham, 
where it was collected by Rudge before 1809. It is now abundant in 
vegetable fields round Kew, being first reported in 1861. It has appeared 
at Guildford, and there is a specimen from Hertfordshire in the Natural 
History Museum, and in 1912 at the Tweedside with other aliens brought 
in wool. It has not spread very far from the Kew locality, though very 
