FREE INSTITUTE OF SCIENCE 



VEGETATION OF SOUTH FLORIDA 



LIST OF PINELAND SEDGES 



4. Cyperus compressus L. 

 3. Cyperus haspan L. 



3. Cyperus Martindalei Britton. 



4. Cyperus Pollardi Britton. 



4. Dichromena floridensis Britton. 

 4. Dichromena latifolia Baldw. 

 4. Fuirena scirpoidea Michx. 



3. Rhynchospora Cymosa Ell. 



4. Rhynchospora divergens Curtis. 

 3. Rhynchospora Grayi Kunth. 



3. Rhynchospora stipitata Chapm. 



3. Scleria ciliata Michx. 



4. Scleria verticillata Muhl. 



4. Stenophyllus Carter! Britton. 



These lists show the character of the ground flora of the Slash-Pine Forma- 

 tion in southern peninsular Florida. It should be emphasized that these 

 species rarely form pure associations, but they are scattered over the forest 

 floor, a species here and another there. The surface soil is fairly well covered 

 with plants, so that at a distance it seems completely covered with annual 

 and perennial herbs, but a close inspection shows that in some cases the plants 

 are widely spaced and separated by the fragments of limestone, or by stretches 

 of bare sand and apparently in open formation. When one considers, how- 

 ever, the possible places where plants can grow between the rocks, the open 

 character of the growth is due to the restrictions of soil room. In other places, 

 the ground flora is much denser and the formation may be considered to be 

 closed. 



Climatic Factors. The rocky soil of these pine forests is well suited to the 

 growth of the citrous fruits, notably the grape-fruit, Citrus decumana Murr. 

 and the orange, Citrus aurantium L. In some cases, it is necessary to blast a 

 hole with dynamite before setting out these fruit trees. Under ordinary con- 

 ditions of weather, the soil is porous and the water which falls as rain is rapidly 

 lost by percolation through the sand and by the limestone holes to the under- 

 ground channels. During the dry season, the plants are under essentially 

 xerophytic conditions and this fact was emphasized in the field notes of the 

 writer during his first and second visits to the peninsula. The slash-pine is 

 structurally a xerophyte and many of the other plants are possessed of 

 xerophytic structures. Notwithstanding the fact that the plants are adapted 

 to meet the conditions of a porous soil, and a high evaporation rate, yet there 

 are seasons when torrential rains fall, when even the soil of the driest pine for- 

 est may be submerged with water for a shorter, or a longer, period. This fact 

 was forced home on the third visit to Florida in June, 1912, when for seven or 

 eight days without much cessation it rained almost continuously until 17 

 inches of rain had fallen. The pine woods on the west coast outside of the 



4 



