\ 
214 Part III. Chapter 5. 
in the coastal plain, hardwood forests of the alluvial bottoms, the mixed 
loblolly and hardwood forest of the interior of the coast plain, the longleaf 
pine forests of the Fayette prairie and the hardwood and shortleaf pine forests 
of the lignitic belt. 
x  Eramples of coastal Species. A large part of the coastal plain flora was 
developed along the edge of the continent in rather restricted localities when 
the shore line was much more depressed than at present. The sea strand 
vegetation and salt marsh vegetation probably originated as such on the strand 
of the Tertiary continent. The distribution of the species of the genus Taro- 
dium is an interesting test case. Tarodium distichum grew, as far north, as 
Greenland in Miocene times. Later its distribution was restricted to the coastal 
plain and Mexico where the Mexican tree, 7. mucronatum, grows according 
to my observations at 5000 to 8000 feet respectively. On the Edwards Plateau 
in Texas, 7. distichum reaches enormous size at the edge of deep hollows at 
altitudes from 1000 to 1750 feet above the sea, hundreds of miles west of the sea, 
hundreds of miles west of the great cypress swamps (Fig. 5.). In all probability 
then after the Lafayette formation had been deposited Tarodium migrated into 
the coastal plain from higher elevations and became differentiated into two 
species 7. distichum and T. imbricarium‘). The absence of any serious ob- 
stacle to plant migration from and to all parts of the eastern section of the 
continent is a noteworthy fact connected with the spread of plants into the 
coastal plain. Completely open on the east and west, the denizens of the 
highland found no hindrance in peopling the new land, after its rise above 
the water. The longleaf pine (Pänus palustris)”), loblolly pine (?. faeda), etc. 
were probably prompt to seize upon the sandy, or gravelly soil of the coastal 
plain after it had been raised from the sea, first after the Lafayette period of 
submergence, later after the Columbia depasiis had been formed and the for- 
mation of these deposits afford a valuble time: index 3). Geologists tell us that 
the coastal plain has been elevated unequally, part at a time. The land soonest 
elevated was probably at once tenanted with forest trees such as the long leaf 
pine with seeds easily disseminated by the wind. As each successive portion 
of the plain was elevated the pine forests would naturally spread. The same 
may be said of the other coastal species which without question entered a 
period of mutation with the opening up of a new land for their occupancy. 
Since this was written, confirmation of it has been found in the discovery by 
ROLAND M. HARPER ©) of Pinus palustris at an elevation above 1000 feet on 
\ . 
1) For the distinction of these species and their habitats see two articles by HARPER, nn 
LAND M. Taxodium distichum and related species. rn Torrey Botanical Club XXIX: 383—399 
also Further Observations on Taxodium do, XXXIT: 05. 
2) name Pinus alustris L. is in N. Am. more common nly used for the Pinus australis 
Michx. — Carat in his Flora of the kn Un. States states: *P. palustris L-, the prior 
but inappropriate name”. (Drd.) 
3) See the reference to the monograph of W. J. MACGEE noted above. ä x 
4) HARPER, R. M.: Some noteworthy Stations for Pinus palustris Torreya V: 60. April 1905. 
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