Exotic Plants in Forests: Supplementary Note 
RoLanp M. HARPER 
While my paper on this subject in the preceding number of 
Torreya (31: 1-7) was in press, there appeared a monograph by 
Paul C. Standley on the Flora of the Lancetilla Valley, Honduras 
(Field Museum Publication 283—Bot. Series, vol. 10—418 PP., 
68 pl., Jan 15, 1931), which contains some interesting observa- 
tions on a similar problem in a tropical environment. Second- 
growth vegetation and weeds (including a few of the same species 
I listed from Lee County, Georgia) are discussed on pages 16-19, 
35-38, 45, 88, and elsewhere: and on pages 27, 41-43, 281, and 
316 the possibility of some of the plants found in dense forests 
and other apparently natural habitats being relicts from long- 
forgotten clearings is indicated. 
; The author states that fruit trees planted by the natives in 
their small clearings often persist for many years after the place 
is abandoned and grown up to jungle again, and then have the 
appearance of accidental introductions, though most of them (like 
the species mentioned in the last paragraph of my article) are 
unable to reproduce themselves. Three important fruit trees 
which are cultivated throughout Central America, namely, Theo- 
broma, Persea and Calocarpum, grow in dense and apparently 
primeval forests on steep hillsides; but in such forests can be 
found many much-weathered fragments of pottery, which may 
indicate that the land was cultivated centuries ago. i 
Some of Mr. Standley’s comments on this are worth quoting 
verbatim. On page 43 he says : “Is it unreasonable to suppose that 
hundreds of years ago these hills may have been cleared and 
planted with corn, just as they are being cleared today by the 
descendants of those aborigines? If these transient clearings are 
surrounded by virgin forest, will not the native plants at some 
time, after the clearings have been occupied by guamil [second- 
growth thickets], reseed them with forest species? Is it not 
possible that these cacao bushes and sapote and avocado trees are 
remnants of plantations of long ago?” He does not seem to men- 
tion fire, and very likely it is a negligible factor in the environment 
of that region, as in dense hardwood forests generally. But pine 
forests and savannas in the tropics, from all accounts, must be 
burned over about as frequently as those in temperate regions, 
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