OF SOME SPECIES AT THE EDGES OF THEIR RANGES 41 
along an outcrop of Helderberg limestone in E. Monroe Co. and 
Wayne Co., C. F. Wheeler.’’ Thus its preferences in one part of 
the edge of its range would make it a calciphile and in another 
part a calcifuge plant. 
Rhododendron maximum is interesting in this connection. Its 
typical habitat is the densest shade in deep forests, where it forms 
impenetrable thickets. This for the most part is its habitat in 
the Sugar Grove area where it is found at the base of the cliffs 
in deep ravines on slopes with a northern exposure. In the 
northern section of the area immediately around Sugar Grove I 
have never seen it except in such situations. But in the southern 
section although likely habitats are common enough it is absent 
except for two isolated patches of small extent. One of these is 
near ‘Written Rock” on Clear Creek and the other is at the head 
of Laurel Run. In both of these stations the plant grows and 
apparently thrives measurably well as a crevice plant high up 
on cliffs with extreme southern exposure in conditions far different 
from its supposed optimum. 
Aralia spinosa was almost exclusively a crevice apie in the 
primeval forest, occurring high up on the faces of the cliffs and 
dropping its seeds into the caves below where they sometimes took 
root, asin Old Man’s Cave. Since the timber of the higher slopes 
has been cut off, the plant has multiplied extraordinarily until it 
has become a common pest on lumbered hillsides. The manuals 
credit it with growing in “‘Damp moist soil in the neighborhood of 
streams.’’ But in the valley of Queer Creek only a single specimen 
and that dead, was found in the moist bottom land. Mohr* 
describes its habitat in Alabama as ‘‘Damp borders of woods and 
copses.”” Hilgard,t page 495, describes it as a lowland plant in 
highly productive calcareous soil and again, on page 515, states 
that with the Liriodendron, black walnut, Kentucky coffee tree, 
and others which are like it normally lowland plants, it may 
ascend in calcareous regions into the uplands as well. The rock 
in whose crevices it occurs in our area is not limestone but a pure 
sandstone which is sometimes quarried for glass sand; the hill- 
sides which it has invaded are very poor land which was originally 
* Mohr, Charles. Plant Life of Alabama. Conk: Nat. Herb. 6:640. 1901, 
+ Hilgard, E. W. Soils. Macmillan Co., 1904. 
