10 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 
Key to the genera of Festuceae—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. BLEPHARIDACHNE. 
14b. Lemma 2-lobed but not deeply cleft, all fertile but the 
UPDELM OS to eS a ee ee 26. TRIODIA. 
12b. Inflorescence an exserted open or spikelike ae pe pwersptev ey soe 15 
15a. Lemmas pubescent on the nerves or callus (except in Tri- 
odia albescens), the midnerve usually exserted as an awn 
OF ‘WUCLO 22.2 Pe a eee eee a eee 16 
16a. Nerves glabrous; callus densely hairy ; lemmas firm; 
paniclewlarge: dittuses as Sees ee eee 15. REDFIELDIA. 
16b. Nerves hairy at least below, the lateral ones often 
CONSPICUOUS]Y.;SO!& sae ae ee ee i i 17 
17a. Palea long-ciliate on the upper half______ 27. TRIPLASIS. 
17b. Palea sometimes villous but not long-ciliate on the 
upper half; perennials___________________ 26. TRtopt1A. 
15b. Lemmas not pubescent on the nerves nor callus (the inter- 
nerves sometimes pubescent), awnless___________________ 18 
18a. Glumes longer than the lemmas; lateral nerves of lemma 
marginal, the internerves pubescent___ 14. DISSANTHELIUM. 
18b. 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. DIARINA. 
19b. Lemmas membranaceous; if firm, the grain neither 
large: nor. beaked= st. . a nae 2 eee 20 
20a. Spikelets subterete; palea longer than the 
lemma, bowed out below____________ 12. Morinta. 
20b. Spikelets compressed ; palea not longer than the 
lemma, not bowed out below________________ PAL 
21a. Lemmas truncate; spikelets 2-flowered. 
11. CATABROSA. 
21b. Lemmas acute or acuminate; spikelets 3 
to many flowered; rachilla continuous, 
the paleas usually persistent after the 
fall of the lemmas___________ 10. ERaGRostts. 
11b. seems 5 to many nerved, the nerves sometimes obscure____--__-__ On 
2a. Spikelets with 1 to 4 empty lemmas below the fertile florets; 
MET VES OW SCUIEs) TIS hits Ti eee ec ene 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 Mestuca) 2222 eee 23 
23a. Lemmas flabellate; glumes wanting; inflorescence dense, 
eylindrie; low annual__- = 25. ANTHOCHEOA. 
23b. Lemmas not flabellate ; glumes present; inflorescence not 
@yMimG nie Pheer er TOURER iN OP ee ee le 24 
24a. Palea winged on the lower half of the keels; spikelets 
linear, in a loose raceme_________________ 5. PLEUROPOGON. 
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. Briza. 
25b. Lemmas longer than broad, the margins clasping 
the palea ; florets not horizontally spreading__-___ 26 
