10 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 



Key to the genera of Festiweae Continued. 

 14a. Lemmas cleft either side of the midnerve to near the 

 base, the lower two sterile, the third floret fertile, the 

 fourth reduced to a 3-awned rudiment- 28. BLEPHABIDACHNE. 

 14b. Lemma 2-lobed but not deeply cleft, all fertile but the 



uppermost 26. TEIODIA. 



12b. Inflorescence an exserted open or spikelike panicle 15 



15a. Lemmas pubescent on the nerves or callus (except in Tri- 

 *odia albescens), the midnerve usually exserted as an awn 



or mucro 16 



16a. Nerves glabrous; callus densely hairy; lemmas firm; 



panicle large, diffuse 15. REDFIELDIA. 



16b. Nerves hairy at least below, the lateral ones often 



conspicuously so 17 



17a. Palea long-ciliate on the upper half 27. TRIPLASIS. 



17b. Palea sometimes villous but not lorig-ciliate on the 



upper half; perennials 26. TEIODIA. 



15b. Lemmas not pubescent on the nerves nor callus (the inter- 

 nerves sometimes pubescent), awnless IS 



18a. Glumes longer than the lemmas ; lateral nerves of lemma 



marginal, the internerves pubescent 14. DISSANTHELIUM. 



ISb. Glumes shorter than the lemmas; lateral nerves not 



marginal, the internerves glabrous 19 



19a. Lemmas chartaceous; grain large and beaked, at 



maturity forcing the lemma and palea open_ 13. DIAEINA. 

 19b. Lemmas membranaceous ; if firm, the grain neither 



large nor beaked 20 



20a. Spikelets subterete; palea longer than the 



lemma, bowed out below 12. MOLINIA. 



20b. Spikelets compressed ; palea not longer than the 



lemma, not bowed out below 21 



21a. Lemmas truncate ; spikelets 2-flowered. 



11. CATABBOSA. 



21b. Lemmas acute or acuminate; spikelets 3 

 to many flowered ; rachilla continuous, 

 the paleas usually persistent after the 



fall of the lemmas 10. EEAGEOSTIS. 



111). Lemmas 5 to many nerved, the nerves sometimes obscure 22 



22a. Spikelets with 1 to 4 empty lemmas below the fertile florets; 



nerves obscure; lemmas firm 18. UNIOLA. 



22b. Spikelets with no empty lemmas below the fertile florets ; nerves 

 usually prominent; lemmas membranaceous (firm in a few 



species of Bromus and Festuca) 23 



23a. Lemmas flabellate; glumes wanting; inflorescence dense, 



cylindric; low annual 25. ANTHOCHLOA. 



23b. Lemmas not flabellate; glumes present; inflorescence not 



cylindric 24 



24a. Palea winged on the lower half of the keels; spikelets 



linear, in a loose raceme 5. PLEUEOPOGON. 



24b. Palea not winged on the lower half of the keels; in- 

 florescence mostly paniculate 25 



25a. Lemmas as broad as long, the margins outspread; 



florets closely imbricate, horizontally spreading- 9. BBIZA. 

 25b. Lemmas longer than broad, the margins clasping 



the palea ; florets not horizontally spreading 26 



