84 



DISTRIBUTION OF PLANTS. 



Agropyrum (repens?; compare No. 7 Our Atlantic States). Growing on the Upland 

 plain ; (possibly indigenous). 



Elymus (No. 15). Growing on the tract of sand-hillocks, and elsewhere. 



Apogonia (No. 1); llottboella of authors. Resembling A. ciliata of Nutt. On the Up- 

 land plain, and elsewhere. 



Andropogon (No. 31); normal. Growing on the Upland plain. 



Azolla (bis No. 2 California and Brazil). Floating in the river ; drifting and collecting 



along the water's edge. 

 Parmelia? (No. 13); a fine species. Adhering to the stem and branches of a shrub; rare, 



once only met with. 



Tropical American Analogies. At so great a distance from the 

 Tropics, under such an entire change in climate and the vegetable 

 growth, the continuance of Tropical forms and genera was unexpected. 

 They were, however, few and rare, and nowhere prominent ; consist- 

 ing of the Mimosa, two Amaryllidacem, and the Cereus. 



North American Analogies. A general resemblance to the un- 

 wooded portion of Arkansas was remarked by Mr. Peale; and not- 

 withstanding the wide geographical interval, some characteristic genera 

 were observed to be in common : as, Grindelia, Stevia ?, Baccharis, 

 Oenothera, Opuntia, Gilia?, the SoJanum with deflected unequal sta- 

 mens, Apogonia, and Agropyrum. Other North American genera were 

 met with : as Sisyrinchium, Anychia, Geraj'dia, Bigelotoia ? or a genus 

 agreeing in habit, Asclepias, Uniola, CeratocMoa, and Spartina. 



European Analogies. After excluding the genera that are com- 

 mon to all cool climates, European Analogies are traceable only in the 

 presence of the ZygopliyJlaceoi, Epihedra, the normal upright Eupjliorhia, 

 and in the Ulex-like Genistoid aspect of certain Compositse. 



Analogies with distant Austral countries. The Austral genera 

 of plants are known to be confined in a very striking manner, each to 

 its own division of the globe : but I was unprepared to find so little 

 in common with Austral Africa on the opposite side of the Atlantic ; 

 amounting to the mere simulating of Helichrysums by certain Labiati- 

 tioral Compositse. 



2. Terra del Fuego. 



Continuing South, the Vincennes on the 14th of February, arrived 

 at the Straits of Le Maire. In sailing through, we left Staten Island 

 in the distance, keeping near the main land of Terra del Fuego. 

 The coast appeared everywhere rocky and rugged, at the base of 



