Ferns of the Dismal Swamp, Virginia. 69 



age duration of direct sunlight received by the frond ; so that the plants 

 on the east side of the ditch face toward the southwest, while those on 

 the west side approximate the southeast, often to the east, according to the 

 amount of foliage about them. The largest frond collected measures 2 

 feet 10 inches (970), its jet black stipe is 2 feet 9 inches long (955) 

 and greatly enlarged at the base. At the outlet canal at the east end of 

 Lake Drummond, where the depth of the canal has drained the adjoining 

 swamp, it is abundant, but harsh and less herbaceous, and was found 

 fruiting abundantly in early June. Plantlets were common. 



12. Woodwardia areolata (Linn.) Moore. Narrow Chain-fern. 



Abundant and growing with its relative except in dryer situations. It 

 is common in low places in the swamp, among the cane and other vege 

 tation and about the bases of the trees. Its delicate fronds grow best 

 where well protected from the sun either by taller vegetation or in wet, 

 densely crowded or well-shaded situations. Prothallium fronds and young 

 plants are numerous on small decaying logs which are well shaded and 

 constantly wet. 



13. Aspleiiium platy neuron (Linn.) Oakes. Ebony Spleenwort. 



Near the western end of Washington ditch a dozen or so plants of vari 

 ous sizes were found growing on well-shaded stumps near the water and 

 mixed with numerous other plants. The fronds are all much broader 

 and longer than specimens of similar age from higher and dryer altitudes, 

 and are more deeply and irregularly incised. The pinnae are wider apart, 

 broader, more blunt, and the basal portion overlaps the rachis. The 

 largest frond measures 18| inches long (476), the longest pinna is If 

 inches (41.5), and the stipe is 3 T 7 6 inches (88). 



14. Asplenium filixfcemina (Linn.) Bernh. Lady-fern. 



Common throughout the sandy woods but not seen in the peaty swamp. 

 A green-stemmed form was the only one found. 



15. Pteris aquilina Linn. Bracken. . 



Seen but sparingly near the upper end of Jericho ditch, where the 

 dredging has formed an embankment. 



16. Polypodium polypodioides (Linn.) Hitchcock. Gray Polypody. 



Extremely abundant but usually high up in the tree tops. It persists 

 for several years on the fallen trees but finally succumbs. It is abundant 

 on the cypresses standing in Lake Drummond, where its usually dry 

 curled fronds may be reached from a boat. In the woods it is rarely 

 found where it can be easily reached. In the streets of Suffolk it is 

 abundant in wide bands on the trunks of the shade trees, usually grow 

 ing in dense masses, mostly on the northern sides and about ten feet from 

 the pavement. 



17 BIOI.. Sr. WASH., VOL. XIII, 1899 



