104 BOTANICAL GAZETTE [august 



These two perennials add little or nothing to the tone of the aspect, 

 as they are of sparse occurrence and decidedly inconspicuous. Ane- 

 mone occurs rarely though widely on upper and middle slopes. 

 Physalis is of rare occurrence on lower slopes, but would be noticeable 

 except for the pendent inflorescence which hides the yellow flowers 

 beneath the leaves. The former rises some 50 to 6o cm , with its 

 exposed cylindrical head of numerous woolly achenes, which are 

 subject to wide dispersal. The immobile fruit of the latter and its 

 ventral position cooperate to insure a very restricted dissemination. 



The last days of the third week and early part of the fourth are 

 marked by the general flowering of three forms, Ratibida columnaris, 

 Smyphoricarpus occidentalism and Verbena stricta, all of primary impor- 

 tance. Gaura parviflora, Linum sulcatum, and Allionia linearis, 

 three flowering forms of minor significance, are added at about the 

 same time. Linum is an annual some 40° m high, occurring sparsely 

 upon the lower slopes. Its humble place in the floral tone is largely 

 due to its limited occurrence, for its yellow flowers (1 . 5 cm in diameter) 

 would otherwise make it a notable element. Gaura is noteworthy 

 mainly as a matter of record, a few specimens only being noted on 

 the middle slope of a northwest exposure. It is an annual and 

 frequently reaches a height of i m or more. Allionia is a perennial 

 occurring rarely upon middle slopes. The straw-colored involucre 

 incloses one to three small purplish flowers and it is always of minor 

 prominence. The anthocarpous fruit has little mobility. About 

 this time are also added two sod-forming species, Festuca octoflora 

 and Aristida purpurea. Aristida is of rare occurrence and con- 

 tributes little to the floral aspect or plant covering. Festuca, on the 

 other hand, is a sod-former of some significance upon lower and 

 middle slopes, being easily replaced however by Poa, which seems 

 to follow it. It is apparently a pioneer form, taking rapid possession 

 of available ground in the open association by means of its heavy, 

 thick, matlike sod. 



In Ratibida the long yellow ligulate ray-flowers first spread about 

 June 20, but it is not until several days later that there is a general 

 display and the tube flowers of the columnar disk begin to open. 

 They flower first in a band at the base of the indeterminate head, 

 progressing up at the rate of about 3 to 5 mm a day. The plants are 



