STATE GEOLOGIST. 163 



STIPA, L. Feather-Grass. Weather-Grass. 



S. Ricliardsonii, Link. Richardson's Feather- Grass. 



North shore of lake Superior, and in Manitoba, Macoun; doubtless reaching into 

 Minnesota. North. 



S. spartea, Trin. Porcupine Grass. 



Abundant southwestward, being the principal grass of the prairie in some districts, 

 and extending undiminished into Dakota ; common north to Clay county and east to 

 New Ulm ; frequent northeast to the sources of the Mississippi, Houghton, and to 

 Sherburne and Anoka counties, and in the southeast part of the state, Upham. (See 

 American Naturalist, yol. xviii.pp. 929-931.) The grain is prolonged below in a stout 

 callus or base, needle-like in sharpness, and above in a long twisted awn ; boih of 

 which are minutely barbed, so that, when insertel in the wool of sheep or in men's 

 clothing, the seed works forward readily but not backward. Thus this very appropri- 

 ately named grass is a serious annoyance at the time of maturity and falling of the 

 seed, which is in July. Within a few weeks later, these seeds are found to have bored 

 into the hard, dry, clayey soil of the prairie to a depth of two or three inches, having 

 been pushed or impelled in some way by means of the awn. Perhaps this is effected 

 by its lengthening, while braced against the herbage above, after it had been con- 

 tracted by partially coiling up, these changes being produced by alternations of dry- 

 ness and moisture, as in days of sunshine and dewy nights ; or, as seems more proba- 

 ble, it may be that the wind, blowing upon the awn, first fastens the sharp-pointed 

 grain in the ground, and afterward slowly drills it downward. This was first brought 

 to the notice of the writer hy Mr. T. M. Young, at the Slsseton Agency, in Dakota, 

 where, late in August, scarcely any seeds of this grass remained on the surface ; but 

 they were found very plentifully thus buried in the ground, often only from a half inch 

 to one inch apart. All had penetrated to nearly the same depth, which was about two 

 and a half inches from the surface to the point of the seed, two thirds of this depth 

 being occupied by the lower part of the awn. 



ARISTIDA, L. Triple- awned Grass. 



A, basiraniea, Engelmann* Triple-awned Grass. 



Minneapolis (plentiful in the vicinity of the University, in the sward on dry sandy 

 land with species of Bouteloua, Poa and Andropogon, from which it is noticeably dis- 

 tinguished by its darker purplish color), Upham; Saint Cloud (plentiful), Campbell; 

 Pipestone City and Luverne, in southwestern Minnesota, and near Rock Kapids, Lyon 

 county, in the northwest corner of Iowa, Lciherg . 



It has also been collected in Nebraska by Rev. J. H. Wibbe, and in Kansas by Mr. 

 E. Hall; and Mr. F. L. ScriJ)7ier and Prof. J. M. Coidter report it from Iowa and Illi- 

 nois. i?et). J". Scott writes that it occurs at Brandon, Manitoba. [Nebraska specimens 

 show a much greater size (20 inches high) and a more branching habit, the culms becom- 

 ing geniculate. Vasey.] 



*Aristida basiramea, Engelmann in a letter to W. Upham. Annual: culms 



erect, 6 to 15 inches high, slender, much branched at the base (some of the branches 

 very short but floriferous), and with short floriferous branches enclosed in the upper 

 leaf -sheaths : leaves comparatively long (3 to 6 inches), narrowly linear, flat, becoming 

 involute toward the apex, sparsely hairy on the margins below, the upper ones nearly 

 equaling the panicle ; sheaths striate, loose; ligule very short, truncate : panicle 1'/^ 

 to 3 Inches long, erect, rather lax, its base sheathed by the upper leaf ; branches of the 

 panicle short, mostly single, the lower in twos or threes; glumes linear, unequal, 1- 

 nerved, lower one 4 lines, upper one 6 lines long including the short bristlo-like point : 

 flowering glume nearly terete, spotted with black, about 5 lines long including the short, 

 acute and hairy callus ; middle awn about 6 lines long, the lateral ones about 4 lines 

 long, spirally twisted below(when mature). Thesheathed flowers are somewhat stnaller. 



This species was discovered last season by Mr. Warren Upham, at Minneapolis, 

 Minn. The late Dr. Engelmann suggested the name, in a letter, as indicative of its 

 habit, and would have published it it he had lived. It is closely related to A. uicho- 



