I 4 6 



GRAMINEAE. 



12. Muhlenbergia pungens Thurb. 

 Prairie Muhlenbergia. (Fig. 331.) 



Muhlenbergia pungens Thurb. Proc. Acad. 

 Phila. 1863: 78. 1863. 



Culms 6 / -i5 / tall from a creeping root- 

 stock, erect from a decumbent branching 

 base, rigid, minutely pubescent. Sheaths 

 overlapping, crowded at the base of the 

 culm, scabrous; ligule a ring of soft silky 

 hairs; leaves i / -2 / long, involute-setaceous, 

 rigid, scabrous; panicle 3 / -6 / in length, open, 

 the branches 2 / -2*4 / long, single, distant, 

 much divided from near the base, the divi- 

 sions apparently fascicled; spikelets on long 

 pedicels, which are clavate-thickened at the 

 apex; outer scales, when mature, equalling 

 or often shorter than the body of the third 

 one, scabrous, especially on the keel; third 

 scale, when mature, tyi"-\" long, scab- 

 rous, the awn shorter than its body. 



On prairies, Nebraska to Utah, south to Texas 

 and Arizona. Aug.-Sept. 



I 



26. BRACHYELYTRUM Beauv. Agrost. 39. 1812. 



A tall grass with flat leaves and a narrow panicle. Spikelets i-flowered, narrow, the 

 rachilla produced beyond the flower and sometimes bearing a minute scale at the summit 

 Scales 3; the outer small and inconspicuous, the lower often wanting; the third much 

 longer, rigid, 5-nerved, acuminate into a long awn; palet scarcely shorter, rigid, sulcale on 

 the back, 2-nerved Stamens 2. Styles short, distinct. Stigmas plumose, elongated. 

 Grain oblong, free, enclosed in the scale and palet. [Greek, in allusion to the minute outer 

 scales.] 



A monotypic genus of eastern North America. 



i. Brachyelytrum erectum (Schreb.) Beauv. Brachyel}-trum. (Fig. 332.) 



Muhlenbergia erecta Schreb. Besch. Gras. 2: 139. pi. 



50. I772-9- 



Brachyelytrum erectum Beauv. Agrost. 39. 1812. 

 Brachyelytrum aristatum R. & S. Syst. 2: 413. 1817. 

 Brachyelytrum aristatum var. Engelmanni A. Gray, 



Man. Ed. 5, 614. 1867. 



Culms i-3 tall, erect, slender, simple, smooth 

 or rough, pubescent at and near the nodes. 

 Sheaths shorter than the internodes, scabrous to- 

 ward the apex, more or less villous especially at 

 the throat; ligule about %" long, irregularly 

 truncate; leaves 2 / -5 / long, 3"-9" wide, acuminate 

 at both ends, scabrous; panicle 2 / -6 / in length, slen- 

 der, branches i'-3' long, erect or appressed; outer 

 scales of the spikclet unequal, the upper less than 

 one-third as long as the flowering scale, the lower 

 minute or wanting; third scale, exclusive of the 

 the awn, 4#"-6" long, 5-nerved, scabrous, espec- 

 ially on . the midncrvc, the awn erect, 9"-i2" 

 long; rachilla produced beyond the flower about 

 half the length of the third scale and lying in the 

 groove of the palet. 





Newfoundland to western Ontario and Minnesota, south to North Carolina, Tenn- 

 M>un. Ascends to 5000 ft. in North Carolina. July-Aug. 



