1889.] NEW YORK ACADEMY OF SCIENCES. 77 



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; Oxytmnia 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 Brodiaea 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 S., 

 in the low and sandy places. Among these grasses other plants 

 grow, not scattered and intermingled as in the East, 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 Oenothera, Sidas, Malvastrums, and Sphaeral- 

 ceas. One or more species of Eriogonum will be found every- 

 where. E. anmmm, Nutt., and E. Wrightii, Torr., with the 

 larger form of E. Ahertianum, Torr., seek the rocky places, 

 while E. cernuum, Nutt., and E. racemosum, Nutt., prefer the 

 grassy plains, and E. tricliopodum, Torn, E. vimineuni, Dougl., 

 and the dwarf form of E. Ahertimium, Torr., grow almost ex- 

 clusively in the sand. Certain plants like Rumex, Bdhia 



