46 Bulletin VII. 1. 



erally ovate or ovate-lanceolate. In the early flowering stage the culms 

 are nearly always simple, and support a single, often long-exserted pan- 

 icle; later the culms become much branched, and the branches are ter- 

 minated by more simple, fewer-flowered panicles, which very frequently 

 are partially enclosed in the leaf-sheaths. The primary panicle, and 

 sometimes the first culm leaves, disappear, and there is left a much- 

 branched grass with numerous, crowded and usually small leaves, and 

 many small, few-flowered, simple panicles. 



15. Panicum clandestinum Linn. 



Plate XI. Figure 43. 



A rather stout, ascending or erect and finally much-branched 

 perennial, three to four feet high, with usually very rough-hispid 

 sheaths and broad leaves. Nodes and internodes smooth, or the 

 latter tuberculate-pilose in the upper part. Sheaths usually very 

 rough tuberculate-hispid, rarely nearly smooth, the outer margins 

 ciliate-pubescent; ligule very short; leaf-blade broadly lanceolate, 

 three to eight inches long, one-half to one and three-fourths inches 

 wide, with a clasping rounded-cordate base and very acute apex, 

 surfaces usually smooth, margins minutely serrulate scabrous and 

 often ciliate near the base. Panicle diffuse, that of the primary 

 stem three to five inches long and finally exserted, those of the 

 branches partly or wholly concealed within the leaf-sheaths; 

 branches of the panicle alternate, decompound to the base, scab- 

 rous, as are the pedicels, which are for the most part longer than 

 the spikelets. Spikelets one and one-half lines long, obovate ellip- 

 tical, smooth or thinly pilose, and usually three-nerved; first 

 glume about one-half as long as the nearly equal nine nerved 

 second and third glumes, the latter with a palea in its axil, the 

 inner or fourth glume minutely pubescent at the apex, otherwise 

 smooth. Leaves on the branches shorter and more crowded, and 

 the sheaths more roughly hairy than on the primary stem. The va- 

 riety pedunculatum A. Gray is based upon the early stage of the 

 species. The primary, terminal, exserted panicle disappears after 

 the development of the lateral branches. 



Common along the banks of streams, rivers and low thickets.. 

 June to September. 



16. Panicum viscidum Ell. 



Plate XI. Figure 44. 



A rather stout, erect or ascending, and finally much-branched 

 perennial, two to four feet high, with the culm and sheaths usually 

 densely pubescent with spreading or deflexed, canescent hairs, and 

 all the parts somewhat viscid when fresh. Ligule a dense ring of 

 hairs about one line long; leaf-blade lanceolate, gradually tapering 

 from near the middle to the very acute apex; sub-cordate at the 

 base, softly pubescent on both sides, minutely scabrous on the 

 margins, villous on the back at the point of union with the sheath; 

 basal leaves ovate, two to four inches long, obtuse, those of the 

 primary culm five to ten inches long, five to nine lines wide; the 

 leaves of the branches more crowded and much smaller. Panicle 

 four to six inches long, ovate or sub-pyramidal, branches com- 

 pound to the base, the lower ones about three inches long, flexuose. 

 Pedicels nearly capillary, usually much longer than the spikelets. 



