6 BULLETIN 461, IT. S. DEPARTMENT OF AGRICULTURE. 



The small grains, while true grasses, have been placed in a separate 

 group (p. 26), as there is more danger of confusing them with each 

 other than with the other grasses. The grasses studied are all 

 common to the eastern part of the United States, and no attempt has 

 been made to include the distinctively western species. 



ANALYTICAL KEY TO GRASS SEEDLINGS. 



GROUP I. — Leaves folded in the bud; shoot apparently flattened. 



A. Auricles narrow and clawlike, clasping the stems more or less. 



1. Perennial rye-grass (LoHum perenne). 

 AA. Auricles wanting, or at least not narrow and clawlike. 



B. Collar hairy. 



C. Stolons present, creeping. 



2. Carpet grass (Axonopus compressus) . 

 CC. Stolons absent. 



D. Leaves less than one-fourth inch wide. 



3. Poverty grass (DantJwnia spicata). 

 DD. Leaves one-fourth inch wide. 



E. Collar divided by the midnerve. 



4. Broom sedge (Andropogon virginicus). 

 EE. Collar not divided by the midnerve. 



5. Yard-grass (Eleusine iudica). 

 BB. Collar not hairy. 



C. Sheaths below ground bright yellow. 



6. Crested dog's-tail grass {Cynosurus cris- 



tatus). 

 CC. Sheaths below ground not yellow. 



D. Blades narrow and bristlelike, but with prominent veins on 

 upper surface. 

 E. Bootstocks wanting ; plant growing in a dense tuft. 



7. Sheep's fescue (Festuca ovina) . 



EE. Bootstocks present ; plant creeping, forming an even turf. 



8. Bed fescue (Festuca rubra). 

 DD. Blades flat ; nerves not prominent. 



E. Blades broad without white lines along midnerve by trans- 

 mitted light; tip of blade taper pointed. 



9. Orchard grass {Dactylis glomerata). 



EE. Blades narrow, with a white line on each side of the 

 midnerve, the leaf being held up to the light and 

 examined with a lens ; tip of blade abrupt, boat 

 shaped. 

 F. Bootstocks usually wanting. 



10. Annual bluegrass (Poa annua). 

 FF. Bootstocks present. 



G. Herbage pale bluish green. 



11. Canada bluegrass (Poa compressa). 

 GG. Herbage dark green. 



H. Ligule short, truncate ; stems smooth. 



12. Kentucky bluegrass (Poa pratensis). 

 HH. Ligule long, acute ; sheaths rough. 



13. Bough-stalked meadow grass (Poa trivi- 



alis ) . 



