[Illustration: The Common Polypody. _Polypodium vulgare_ (Photographed by Miles Greenwood, Melrose, Mass.)]
Fronds oblong, two to seven inches long, deeply pinnátifid, gray and scurfy underneath with peltate scales having a dark center. Fruit-dots rather small, near the margin and obscured by the chaff.
[Illustration: Gray or Hoary Polypody. _Polypodium incanum_]
In appearance the gray polypody is much like the common species, as the Greek ending _oides_ (like) implies. In Florida and neighboring states it often grows on trees; farther north mostly on rocks. Reported as far north as Staten Island. It is one of the "resurrection" ferns, reviving quickly by moisture after seeming to be dead from long drouth. July to September. Widely distributed in tropical America. Often called Tree-Polypody.
Sporangia near or on the margin of the segments, the reflexed portions of which serve as indusia.
_Ptèris aquilina_. PTERÍDIUM LATIÚSCULUM[1]
[Footnote 1: The use of small capitals in the scientific names indicates in part the newer nomenclature which many botanists are inclined to adopt.]
Fronds broadly triangular, ternate, one to three feet high or more, the widely spreading branches twice pinnate, the lower pinnules more or less pinnátifid. Sporangia borne in a continuous line along the lower margin of the ultimate divisions whose reflexed edges form the indusium. (Greek, _pteron_, a wing, the feathery fronds suggesting the wings of a bird.)
[Illustration: Common Bracken or Brake, a Sterile Frond. _Pteris aquilina_ (Providence County, R.I.)]
[Illustration: A Fertile Frond of Common Bracken. _Pteris aquilina_ (Suffolk County, Mass.)]
"The heath this night must be my bed, The bracken curtain for my head." SCOTT.
The outlines of the young bracken resemble the little oak fern. It flourishes in thickets and open pastures, often with poor soil and scant shade. It is found in all parts of the world, and is said to be the most common of all our North American ferns. In a cross section of the mature stipe superstition sees "the devil's hoof" and "King Charles in the oak," and any one may see or think he sees the outlines of an oak tree. It was the bracken, or eagle fern, as some call it, which was supposed to bear the mysterious "fern seed," but only on midsummer eve (St. John's eve).