486 BOTANICAL INFORMATION. 
the former, and growing about twice as high. Amongst 
these stand preeminent as the most showy :—Asclepias tube- 
rosa, Phlox aristata, (varying, in its native place, so much in 
colour, as to resemble the Dianthus barbatus of the gardens) ; 
then come Petalostemon violaceum and candidum, Salvia 
azurea, Lilium Canadense, Melanthium Virginicum, and Bap- 
tisia azurea. Later still, towards August, the Composite reign 
almost alone, from Helianthus angustifolius, Actinomeris 
helianthoides, Ambrosia trifida and Silphium connatum, 
(growing 5-15 feet high in the most fertile spots) to the dwarf 
Aster sericeus of the adjoining limestone-hills. 
Great difficulties presented themselves to us while tra- 
versing this beautiful country. Rivers, with steep banks of 
50 or 60 feet in height, where we had to let our waggons and 
baggage-carts down upon ropes ; and sudden rises of water, 
peculiar to these streams, and which when full, defy almost 
any attempt to cross them, resembling so many torrents. 
Daily we had to traverse some or other of the smaller rivers, 
and often were obliged to construct bridges by felling a large 
tree, and carrying our baggage over, and then swimming the 
horses through. 
Towards the sandy barriers of the valley of the lower 
Platte, the Missouri limestone disappears almost entirely 
above the surface, leaving only extensive platforms, slightly 
covered with earth. Such rocky tracts are clothed all over 
with the beautiful Astragalus assurgens of Hooker. It varies 
of every shade, from pure white to vivid pink, deep purple 
and violet ; Astr. caryocarpus is its constant companion, very — — 
remarkable for its large wallnut-shaped fleshy legumes, grow- — 
ing in bunches, and stretching in a circle around the plant — 
. on the stony ground or limestone rock. Another pretty 
plant, the Malva Munroana, is often found with the two fore- — 
going, likewise groups of Verbena Aubletia, with Calymenia 
nyctaginea, Batschia longiflora, and Hedeoma. hispida. : 
The ridges and slopes of the ravines are studded with - 4 
Ceanothus Americana, Amorpha canescens, and Tephrosia : 
Virginiana, while the level prairies present dense masses of 
