1889. | NEW YORK ACADEMY OF SCIENCES. T7 
misias and Ephedras. The alkaline flats are densely covered 
with a half-shrubby growth—through which travel is nearly im- 
possible—of Dicorea Brandegei, Gray; Oxytenia acerosa, Nutt., 
and many species of Atriplex and other Chenopodiaceous and 
Amarantaceous plants. Upon the sides of some of the canyons 
occurs an extensive growth of shrubs, but these spots for the 
most part are exceedingly dry and barren, reflecting back the 
sunshine from their bare rocks, and maintaining a temperature 
most trying to the endurance of the collector. Upon these 
plains there has once been an extensive forest growth, as in- 
dicated by the petrifactions that occur. Some of these silicified 
trunks are of great size. One that I found near Holbrook 
measured eleven feet from a point just beyond the centre on one 
side to the periphery upon the other. ‘The remaining portion 
had separated and fallen down the hillside. 
The table-land is a never-ceasing source of surprises to us from 
the East. During the greater part of the year the surface is dry 
and desolate, of an ashy gray color; but immediately upon the 
occurrence of the annual rains it changes with marvellous 
rapidity. Within three days after the first important showers, 
a distinct tinge of green is perceptible. In a week the surface 
is of an almost uniform light green, and in from ten days to 
two weeks it presents an appearance of great luxuriance. From 
this time on, until the occurrence of killing frosts, it is a 
paradise for the collector. Among the earliest plants to mature 
are those which spring from bulbs, including several beautiful 
species of Allium and Calochortus, and a Brodixa or two. 
Among grasses, Boutelouas and Aristidas are most abundant 
over the general surface, with Poas, Agrostis verticillata, Vill., 
Ammophila longifolia, Benth., and Setaria caudata, R. and S8., 
in the low and sandy places. Among these grasses other plants 
grow, not scattered and intermingled as in the Hast, but each 
species occupying a larger or smaller area almost independently. 
Thus we find patches of golden Pectis, Gutierrezia, Viguiera, 
Verbesina, Hymenatherum, and Hymenopappus, showy purple 
Astragali and brilliant many-colored Pentstemons and scarlet 
Castilleias. In the slightly elevated, broken ground, where the 
growth of the grasses is disturbed, abounds the Argemone, 
showy species of (inothera, Sidas, Malvastrums, and Spheral- 
ceas. One or more species of Hriogonum will be found every- 
where. #. annuum, Nutt., and #. Wrightii, Torr., with the 
larger form of 4. Abertianum, Torr., seek the rocky places, 
while #. cernwum, Nutt., and #. racemosum, Nutt., prefer the 
grassy plains, and LZ. trichopodum, Torr., 2. vimineum, Dougl., 
and the dwarf form of 2. Abertianum, Torr., grow almost ex- 
clusively in the sand. Certain plants like Rumex, Bahia 
