ALTAMAHA GRIT REGION OF GEORGIA 87 



About one-eighth of the species in the above list are ever- 

 green, but most of the evergreens are not abundant, so the sand- 

 hills have quite a desolate appearance in winter. There are half 

 a dozen or more perennial herbaceous vines, but these usually do 

 not climb. Instead they trail over the bare sand, where there is 

 plenty of room. Perennial herbs are in the majority here as in 

 most of the groups already discussed, but there are more an- 

 nuals on the sand-hills than in any other habitat. 



Almost every sand-hill plant has some evident contrivance for 

 reducing transpiration. Quercus Catesbcsi, the commonest species, 

 is a good example. Its leaves are coriaceous, apparently 

 about alike on both sides, and turned at all sorts of angles to the 

 horizon, so that only a few of them receive the full effect of the 

 sun's rays at any one time. Glaucous and woolly leaves are quite 

 common. Asclepias humistrata (see plate XIX, fig. i.), Baptisia 

 perfoliata, Polygonella gracilis, Chrysopsis gossypina, Serico- 

 carpus bifoliatus, Chrysoma pauciflosculosa, and probably other 

 species, have their leaves vertical, and alike or nearly so on both 

 surfaces. 1 In Stipulicida sctacea, one of the slenderest plants 

 imaginable, and many other species, the same end is accomplished 

 by reduction of leaf-surface. 2 



There are few spring flowers on the sand-hills, which is not 

 surprising, since it is well known that vernal -flowering plants 

 are usually most numerous in dense deciduous forests, where the 

 ground is covered with humus, and the sand-hills are just the 

 opposite of this. The species which bloom before April are 

 mostly trees. The annual plants mostly bloom between July ist 

 and October ist. The height of the flowering season for the 

 Whole sand-hill flora seems to be in September. (See diagram.) 

 The average length of the flowering period is 51 days. 



The proportions of the various colors of flowers are almost the 

 same as in dry pine-barrens. Only 20 species are anemophilous, 

 and of the entomophilous ones about 36 have white flowers, 

 12 cream-colored, 21 yellow, 9 purple, and 12 blue. Apparently 

 the sand-hill insects are not as fond of purple as are those which 



1 See Bull. Torrey Club, 30: 336, 339. 1903. 



2 The frequent occurrence in this group of such specific names as angus- 

 tijolia, filifolia, gracilis, lanceolata, pectinata and tenuijolia is suggestive. 



