76 PLANT LIFE OF ALABAMA. 



vations thus formed are called by the people of the country " rook 

 houses." In these gloomy recesses, never visited by the direct rays 

 of the sun, their roofs and walls constantly moistened by the water 

 oozing from every crevice, some of the rarest and most delicate ferns 

 find a shelter from wind and sudden changes of temperature. Triclio- 

 manes peter sii, the tiniest of this order in the United States, and con- 

 fined to northern Alabama, is at home in these rock houses, and thence 

 it was first brought to light by Judge T. M. Peters, who discovered it 

 on the banks of the head waters of Sipsey River. The filiform hori- 

 zontal rhizomes are interwoven into dense patches, their fronds of 

 dark green scarcely an inch high, somewhat resembling the thallus of 

 a large liverwort. This fern was subsequently found in a similar 

 locality on the western edge of the table-land by Prof. E. A. Smith, 

 and later by the writer on its eastern border at the falls of Black 

 Creek, in Etowah County. Trichomanes radicam is also a frequent 

 inhabitant of these rock houses, being found on wet, deeply shaded, 

 rocky walls northward to the Cumberland Mountains of Kentucky. 

 The long creeping rootstock of this beautiful fern, adhering firmly to 

 the rock, decorates the roof and walls of these recesses. A&pleftiwm 

 trichomanes, with its fronds of brightest green, ana the thallus of a 

 large liverwort (Dumortiera sp.) are the frequent companions of the 

 above. Of plants of higher orders only a few have been observed in 

 these cavities. Thin grass (Agrostis perennanx) with its weak, decum- 

 bent stems, occurs here, where its foliage is scarcely ever affected by 

 frost and never touched by the direct sunlight, and Heuchera rugelri 

 is also quite frequently found on the damp ledges which form the 

 threshold of the caves, but rarely penetrates beyond them. 



Hydrophytic %>lant associations (paludial plants). On the table-land 

 beyond the channels of the large streams and their very numerous 

 branches no areas of great extent of a water-soaked or submerged 

 soil are found, and the narrow channels through which the water 

 rushes toward the lowlands afford but little chance for the spread of 

 a hydrophile vegetation. The wet grassy swales are inhabited by the 

 following: 



Andropogon virginicus. Car ex granularis. 



Homalocenchrus (Leersia) Virginia**. Eteocharis tennis. 



Panicularia nervata. Eleocliaris acicularis. ' 



Panicum rostratum. Eleocharis ovata. 1 



Panicum commutatum. Scirpus polyphyllus. 



Panicum polyanlhes. Dichromena colorata. 



Panicum sphaerocarpon. Kobresia pumila. 



Carex lurida. Juncus marginalus. 1 



Carex lupulina. Juncus (common species) . 



Carex intumescens. ' Cicuta maculaia. l 



Carex squarrosa (rare) . Coreopsis tripteris. 1 



Carex torta. Eupatorium maculatum.^ 



Occurs also in the Louisianian area. 



