194 BOTANICAL GAZETTE [SEPTEMBER 
This transect is typical of the greater part of the road. Near 
Gleneyrie Machaeranthera cichoracea appears in abundance in 
the frontal zone. At the lower end of the mesa road is found 
considerable variation. Cleome serrulata forms the frontal zone, 
and with this Boebera papposa, Xanthium commune, Polygonum 
aviculare, Verbena bracteosa, Munroa squarrosa, Amaranthus bli- 
toides, Solanum rostratum, Chenopodium album, and Malvasirum 
coccineum. Just back of this, on a portion of the old roadway, is 
Stipa Vaseyi, with Boebera papposa, Euphorbia dentata, Chenopo- 
dium leptophyllum, Ambrosia artemisifolia, Sophora sericea, Poly- 
gonum aviculare, Schedonnardus paniculatus, Bouteloua oligostachya, 
Muhlenbergia gracillima, Artemisia frigida, Xanthium commune, 
Carduus undulatus, Iva xanthijolia, Asclepias pumila, and Salvia 
lanceolata. The advance on the graded graveled part is made 
almost entirely by annuals, Boebera papposa, Verbena bracteosa, 
Amaranthus blitoides, or in rare cases Solanum rostratum is most 
important, while other species are generally present in reduced 
numbers. The soil in these cases has been packed down and Stipa 
Vaseyi does not enter. 
The old mesa road is not followed by the new in all places. In 
the lower end of the mesa it turns to one side. Here through the 
original formation, it was only a path. It had been worn down 
and when abandoned the soil, through the agency of frost and rain, 
had loosened and fallen in at the sides, This road is now revege 
tated with Stipa Vaseyi, which is in many places replaced by Muh- 
lenbergia gracillima and Bouteloua oligostachya. In one place this 
vegetation is practically identical with the formation. 
The successions on trails vary considerably in different parts of 
the region. As one travels from Colorado Springs to Palmer Lake 
changes are soon noted. A short distance above Colorado Spnng 
Boebera papposa becomes less abundant and the first species 10 
invade the roadway is Plantago Purshii. Above Monument 5!?¢ 
Vaseyi drops out as an invader, and the principal species which enter 
are Polygonum aviculare, Lappula occidentalis, Verbena bracteosa, 
Amaranthus blitoides, A. retroflexus, Salvia lanceolata, and Ramet 
acetosella. Below Monument a short distance the following SY“ 
cession was noted: +The advancing zone was made up of Lepidiu™ 
