1922] ^ Fernald,—Polypodium virginianum and P. vulgare — 133 
in the novel habitat that he specially recorded the discovery, the 
Polypody growing on the “trunk several feet above the base, after 
the manner of P. incanum . . . The roots have taken a firm 
hold in the clean living bark, so that I collected my specimens with 
a knife, leaving the bark attached."' In 1884, in their paper on 
Canadian Filicineae, after stating the range and the ordinary habitat 
of the plant in Canada, Macoun & Burgess added as a noteworthy 
item: "growing plentifully on old elm trees, near Belleville, Ont., 
near Heely Falls, Trent River, Northumberland Co., Ont., and near 
Amherstburg, Essex Co., Ont."? In 1903 Waters? published a photo- 
graph, taken apparently near Baltimore, of “The Polypody at the 
Base of a Tree”. In September, 1906, Professor J. Franklin Collins 
showed me at Lincoln, Rhode Island, several trees of Betula lenta with 
festoons of Polypody hanging from the lower halves of the trunks, 
and he was so interested in the novelty that he photographed the 
colony; and similar occurrences in Nova Scotia, observed in 1920, 
seemed so unusual as to merit the note: “ Polypodium vulgare |i. e. 
P. virginianum], here having no rocks to grow on, was climbing the 
tree-trunks, the creeping rootstocks ascending in the crevices of the 
bark to a height of 2 or 3 meters" 
climbing Polypodium again.”4 Almost simultaneously, Professor 
Duncan S. Johnson discussed in some detail the occurrence of the 
. eastern American Polypody on trees near Baltimore, this habitat 
being so unusual in his experience that he had “not been able to find 
a definite report of its being really epiphytic in habit in the United 
States." ^ In Europe and Pacific America, then, although often 
occurring on mossy rocks and wooded banks, P. vulgare 1s frequent 
on living or dead trees; but the eastern American P. virginianum, 
though very rarely epiphytic, is ordinarily a plant of rock-habitats. 
In view of the similarly stout and firm, sweetish rhizome with 
peltately attached scales of similarly dense structure, the identical 
- fronds with often very broad pinnae (up to 1.8 em. and rarely to 4 
cm.) bearing median sori, the clearly intergrading venation, and the 
and at another station “the tree- 
1L. F. Ward, Field and Forest, iii. 150 (1878) and report in Bull. Torr. Bot. Cl. 
vi. 238 (1878). 
? Macoun & Burgess, Trans. Roy. Soc. Can. ii. Sect. iv. 181 (1884). 
3 Waters, Ferns, 82 (1903). 
4 Fernald, Ruopona, xxiii. 147, 149 (1921). 
5D. S. Johnsón, Bot. Gaz. Ixxii. 237 (1921). 
