-fig- 



aureum, already well pointed out by Mr. Gilbert, are ample for 

 even the casual observer, the presence of sterile and fertile pinnae 

 on wholly separate fronds being especially marked. 



On the same key, near the village of Aiken, our party unex- 

 pectedly encountered three of the typically southern Polypodiums. 

 We entered a dark, moist forest, composed largely of madeira- 

 wood and the Florida sumac, and were at once attracted by the 

 glossy green fronds of P. phyllitidis, growing in large clumps 

 directly on the ground. At first it appeared that this handsome 

 species held undisputed sway over that particular woodland; but 

 a little further examination revealed the delicate climbing stalks 

 of P. Swartzii around the bases of the tree trunks, adhering so 

 closely to the bark that they could not be removed except with 

 the aid of a knife. It was too early in the season to obtain fruit- 

 ing fronds, and I am inclined to believe that in this locality, at 

 least, the fern does not fruit freely. The pinnae are so delicate in 

 texture that they do not survive the dry period from fall to spring, 

 but start into fresh growth in March. While collecting specimens 

 of Swarizii a single plant of what afterward proved to be P. 

 Plumula was detected on a dead tree trunk. This fern, like P. 

 polypodioides, withers and ceases to grow during the dry season, 

 but the fronds remain evergreen so that they revive and turn 

 green with the first rainfall. 



Pteris caudata occurs frequently on these islands, particu- 

 larly in the subtropical jungles of Sugar Loaf Key. It is impossi- 

 ble for one who has examined this noble fern under natural con. 

 ditions to regard it as a mere variety of the familiar northern 

 "brake." The fronds are much more decompound, the ultimate 

 segments being uniformly narrowly linear. In stature it is above 

 the average height of P. aquilina, numerous specimens exceed- 

 ing six feet. Its habitat, almost invariably densely wooded thick- 

 ets, is also characteristic, and its range is exclusively subtropical 

 and tropical. I am convinced that much of the misconception has 

 arisen from the fact that numerous specimens from northern 

 localities have been wrongfully referred by collectors to "P. 

 aquilina, var. caudata" 



Pteris longifolia is one of the most abundant ferns on the 

 keys, growing in various situations. At Miami, on the shore of 

 Biscayne Bay, we also collected Polypodium aureum and Vittaria 

 lineata, but neither of these were observed on the islands, prob- 

 ably because both species are epiphytic on the cabbage palmetto, 



