ALTAMAHA GRIT REGION OF GEORGIA 61 



The commonest method of dissemination seems to be by 

 smooth seeds contained in erect capsules, calyces, or honey- 

 comb-like receptacles opening at the top and borne on stiff erect 

 stems which persist through the winter. When such a stem is 

 bent suddenly to one side the seeds are discharged by centrifugal 

 force. Good examples of this (called by Dr. Clements tono- 

 boles x ) are seen in 40 or 50 species, belonging to Baldwinia, 

 Gerardia, Mesosphcsrum, Sabbatia, Ludwigia, Rhexia, Hypericum, 

 Linum, Sisyrinchium, Lilium, Juncus, Xyris, and doubtless 

 several other genera. About 25 species have wind-borne seeds 

 or achenes, and a few of the shrubs have fleshy fruit. Adhesive 

 fruits seem to be entirely wanting, 2 unless the achenes of the 

 Rhynchosporas with their barbed bristles function in this manner. 

 The plants of this habitat-group evidently do not depend much 

 on animals to carry their seeds. 



The list contains 187 species in 105 genera and about 46 fam- 

 ilies. The largest family is Cyperaceae, with 27 species. Com- 

 positae is a close second, with 24, and Gramineae third, with 16. 

 Rhynchospora is the largest genus in moist pine-barrens (as well 

 as in the whole Altamaha Grit region), with 13 species. No other 

 genus has half as many. The total absence of the Euphor- 

 biaceas and Leguminosae, and of all families between Mag- 

 noliaceae and Myricaceae, is noteworthy. Over two-fifths of 

 the whole list (43.6% of the angiosperms) are monocotyledons. 

 This accords with the common belief among botanists that plants 

 growing in wet places are as a rule not as highly organized 

 as others. Although no forms of vegetation below the ferns 

 have been observed in these moist pine-barrens, it is altogether 

 probable that some species of Sphagnum could be found, and 

 perhaps also some of the minute parasitic fungi. 



The plants of this group do not seem to be quite so restricted 

 in range as those in the intermediate pine-barrens. About 

 60 species, or nearly a third, are confined to the pine-barrens of 

 the southeastern states, while an equal number reach their 

 northern limits in the coastal plain somewhere between New 



1 Bot. Sum. Neb., 7: 47. 1904. 



2 Compare this with a statement in Bull. Torrey Club, 31 : 16. 1904. 



