58 American Midland Naturalist Monograph No. 2 



l.Spikelets 2-3 mm. long. 

 2. Awns scarcely exceeding the glumes; shallow water and wet banks. May- 

 July. [A. aristulatus Michx.] A. aequalis Sobol 



2. Awn bent, exserted from the spikelet 2 mm. or more. 



3. Plants perennial; stems decumbent and rooting at the nodes; anthers 



1.5 mm. long; in water and wet ground. June-July. Water Foxtail 



A. geniculatus L. 



3. Plants annual; stems tufted, branched at the base; anthers 0.5 mm. 



long; ditches and fields. [A. ramosus Poir.} ....A. carolinianus Walt. 



35. Phleum L. 



P. pratense L. Timothy. Roadsides and fields, very common; nat. from 

 Eur. June- July. 



36. Muhlenbergia Schreb. 



1. Panicles narrow, not diffuse or spreading. 



2. First glume obsolete or nearly so, the second minute, truncate; lemma 



long-awned; fields and dry woods. July-Oct. Nimble Will 



M. schreberi J. F. Gmel. 



2. Glumes at least half the length of the lemma, or longer. 

 3. Plants with conspicuous scaly rhizomes. 



4. Lemma awnless or nearly so; anthers 0.5-1 mm. long. 



5. Glumes lanceolate or oval, cuspidate, about half or two-thirds the 



length of the lemma; rocky woods. July-Oct 



M. sobolifera (Muhl.) Trin. 



5. Glumes subulate. 



6. Glumes equalling the lemma, or somewhat shorter, awnless or 

 short-awned. 

 7. Intemodes of the stem glabrous. 



8. Panicles shortly exserted or partly included in the sheath; 



fields, roadsides, waste places, common. Aug.-Sept 



M. mexkana (L.) Trin. 



8. Panicles usually well exserted; woods. Aug.-Oct 



M. brachyphylla Bush 



7. Internodes of the stem puberulent. 



9. Lemma short-pilose at base (on the callus) ; moist woods 



and thickets. Aug.-Oct M. foliosa (R. & S.) Trin. 



9. Lemma not pilose at base; woods, chiefly in the s. and 



centr. parts of the state M. glabriflora Scribn. 



6. Glumes much longer than the lemma, owned; panicle dense, 



somewhat interrupted; wet ground. Aug.-Sept 



M. racemusa (Michx.) BSP. 



4. Lemma long-awned. 



10. Spikelets 3-4 mm. long; glumes lanceolate, awn-pointed, shorter 

 than the lemma; anthers 1-1.5 mm. long; rocky woods. July- 

 Oct M. tcnuiflora (Willd.) BSP. 



