HO JOURNAL OF THE ARNOLD ARBORETUM |vol. v 



rivulet, and except in rainy seasons into a dry ravine. At other times its 

 waters may be seen dashing over the rocky bed, and occasionally spreading 

 out into quite pools, with a border of small trees and shrubs growing 

 amongst the masses and boulders of dark stained sandstone. The valley 

 varies in width from a few rods to a quarter of a mile or more, and where 

 it has not been cleared off is covered by a fine growth of Pine, Oaks, Hick- 

 ories, Sweet Gum, Sugar Maple and many other trees, which will be 

 mentioned in more detail later. Bounding the valley, and in places coming 

 down almost to the margins of the stream, rise on both sides the steep 

 slopes of the mountains. That on the north is Blackfork, and to the south 

 lies Rich Mountain. The little stream between them bears the somewhat 

 ambitious name of Big Creek, a title which would appear to be appro- 

 priate only at seasons when it carries the heavy run-off from the mountains 

 after torrential rains. Many interesting plants, including a variety of 

 trees and shrubs, grow along its margins, and some of them even amongst 

 the water-worn rocks of its channel, where they are borne down and sub- 

 merged by every flood. 



Conspicuous amongst herbaceous plants along this rocky channel are 

 the Willow-herb (Dianthera americana L.) and Letterman's Ironweed 

 {Vernonia Lettermanni Engelm.). Two shrubs are also quite abundant 

 here: the Silky Dogwood or Kinnikinnik (Cornus obliqua) and Ward's 

 Willow (Salix longipes var. Wardii). This Willow, so common along many 

 of the rocky streams of the Ozarks, sometimes becomes a small tree under 

 favorable conditions, but here, by reason of being so frequently buffeted 

 and broken down by the torrents, it seldom exceeds a meter or two in 

 height and sends out many shoots from the old stumps. In foliage, too, 

 it is rather a distinct form, perhaps worthy of segregation, the leaves being 

 firmer and the shoots having smaller stipules than in the typical form. 

 Cephalanthus occidentalism Alnus rugosa, Hamamelis vernalis, Callicarpa 

 americana and Amorpha tennessensis sometimes also venture into this 

 perilous habitat, but they are more characteristic of the rocky margins 

 of the stream, where they are dominant species, but where their sway is 

 also disputed by many others. Occasionally the border of the channel 

 or deep pools is demarked by low bluffs or huge boulders where shrubby 

 specimens of Amelanchier canadensis or Acer rubrum like to grow. More 

 frequently there is a wide low margin of gravel or coarse rubble, amongst 

 which sand and silt have accumulated, and since it is frequently flooded and 

 the ground water is always near the surface here, something like bog 

 conditions prevail. A dense growth of shrubs and herbaceous plants 

 occupy the less exposed spots of this peculiar flood plain. The royal fern 

 and the pretty little Iris cristata Ait., Viola blanda Willd., and many 

 other attractive flowering plants, including several orchids, may be found 

 in such situations. Conspicuous shrubs and small trees are Carpinus 

 caroliniana, Ostrya virginiana, Cercis canadensis, Rhus Toxicodendron, 

 Vaccinium stamineum, Xolisma ligustrina, Rhododendron roseum, R. 



