72 THE ROYAL SOCIETY OF CANADA 



and petioled, the upper linear, entire or slightly serrate with ciliated 

 margins. The heads are arranged on one side of the branches of the 

 short but broad panicle. 



(B) Plants from the Clayey, Depressed Areas 



1. Cladonia pyxidata (L.) Fr. This is a grayish-green lichen, 

 with short, thick ascending lobes. Macoun says that it is common 

 everywhere throughout Canada on earth, rocks, logs and stumps. 

 The brown apothecia are situated on the margins of the grayish-green 

 stalked, open cups. Such lichens are the first plants to appear on ex- 

 posed surfaces after slides and "blow-outs." In. the Great Plains, as 

 soon as soil has been prepared by them, Artemisia and Gutierrezia 

 are apt to succeed. In this instance, the lichens formed expanded 

 groups associated with Artemisia and clusters of Antennaria leaves. 



2. Polytrichum piliferum, Schreber. This moss is found in the 

 northern regions of both the old and the new world. The specimens in 

 this case showing no inflorescences, the determination is only pro- 

 visional. The leaves, however, were characteristic, bearing numerous 

 lamellae and terminating in a long white awn. The lower half of the 

 stem was naked. 



3. Bouteloua gracilis (H.B.K.) Lag. It is shorter on the lower 

 than on the higher ground, and shows the characteristic blue-green 

 colour, whereas on the higher ground the colour is brownish be- 

 cause of approaching maturity. 



4. Opuntia polyacantha. Haw. (Cactaceae). This is a prickly 

 pear cactus with prostrate, conspicuously jointed stems, the inter- 

 nodes being obovate, and pale green. The stout spines, from 5 to 

 15 in mJmber and from 1 to 5 cm. long, are either deflexed or spread- 

 ing. In the late spring and summer, it bears yellow flowers, followed 

 by spiny fruits. The range is from Saskatchewan to British Columbia 

 and south to Missouri, on plains and prairies. Mr. Stansfield reports 

 that it was common in the "burn-outs" of southern Saskatchewan, 

 but not present on the higher sandy parts of the same district. 



5. Astragalus, Sp. A fragment of one of the Leguminosae 

 suggested a milk vetch or Loco Weed. It was, however, impossible 

 to determine this without flowers, fruits and complete leaves. 



6. Potentilla bipinnatifida, Dougl. Like other plants from the 

 lower level, this cinquefoil was much shorter, smaller and less ad- 

 vanced than specimens from the higher areas. 



7. Antennaria campestris, Rydb. Rosettes of leaves and por- 

 tions of stems with roots were collected but no flowers were obtained. 

 The plant seems, however, to be the everlasting called "Cat's-foot." 



