EXOTIC PLANTS ABOUT LONDON IN 1865. 147 
—In Peruvia, prope Casapi (Mathews, n. 1689, Herb. Kew.).—Herba, 
caulis piloso-pubescens, foliorum maj. limbi 0,05 longi 0,03 lati, 
petioli 0,008 longi. 
(To be continued.) 
EXOTIC PLANTS ABOUT LONDON IN 1865. 
By Henry Trimen, M.B. Lonp., F.L.S. 
The year 1865 was remarkable for its high temperature from April, 
to September. The average temperature of April was (roughly speak- 
ing) 53? F., being no less than 6:75? F. above the mean of the last 
fifty years. On the 27th the highest temperature ever registered in 
the month was noticed, 81:5? F. May, June, and July all showed a 
mean temperature considerably above the average, and there were some 
remarkably high readings registered, but the mean temperature of 
August fell somewhat below the usual average (1:0? F.). The first 
twenty days of September were excessively hot, the average of that 
period, 64:5? F., is 10? F. above the mean of fifty years. Scarcely a 
drop of rain fell during three weeks. On the 8th, 86° F. was regis- 
tered, a temperature never equalled in September (except on 6th, in 
1846) ; and the mean temperature, 72-1? F., was higher than that of 
any day since August 12th, 1861. On the 20th, a thermometer hung 
in the open air facing the south at Southampton showed, at 11 A.M., 
119?F. The mean temperature of the month was nearly 64° F., being 
about 7:5? above the mean of the last fifty years. 
The mean temperature of the whole of the six summer months (April 
to September inclusive) was about 3? F. above the mean of the same 
six months during fifty years. 
This unusual heat could not but influence vegetation to an impor- 
tant extent. It may, therefore, be worth while to put on record the 
Occurrence of numerous exotics about London last year, the luxuriant 
growth of some which I believe to be possible in this country only in 
years with an exceptionably high mean summer temperature. 
Mitcham, Surrey, has a rich soil in good cultivation, and the neigh- 
bourhood has long been known as a garden on a large scale for the 
growth of officinal plants. Ona farm to the north of the Common 
; L 2 
