Key to PoaceaeView taxon page for PoaceaeJepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.
1. Leaf blade base constricted above sheath, forming false petiole; stem woody ..... [PHYLLOSTACHYS]
1' Leaf blade base not constricted, not forming false petiole, forming open or closed tubular sheath; stem generally herbaceous
2. Spikelets enclosed in bristly to spiny, burlike involucre ..... CENCHRUS
2' Spikelets not enclosed in bristly to spiny, burlike involucre
3. Some or all florets modified into bulblets with conspicuous, awnlike tails ..... Poa bulbosa subsp. vivipara
3' Florets not modified into bulblets
4. Leaf blades, at least upper, generally stiff at maturity, sharppointed and conspicuously arranged in 2 vertical rows
5. Spikelets unisexual, plants generally dioecious; plants of salt marshes and moist alkaline sites ..... DISTICHLIS (2)
5' Spikelets bisexual; plants known only from sand dunes in Inyo Co. ..... SWALLENIA
4' Leaf blades generally soft, rounded to acute, but not sharppointed (except Blepharidachne, Munroa), not conspicuously arranged in 2 vertical rows (except Muhlenbergia asperifolia)
6. Leaf blade and sheath undifferentiated; stem internodes solid; ligules 0
7. Spikelets 2ranked on inflorescence axis ..... ORCUTTIA
7' Spikelets spirally inserted on inflorescence axis
8. Plant glandularsticky at maturity; inflorescence a dense, cylindric spike, generally fully exserted at maturity; spikelets dorsally compressed ..... NEOSTAPFIA
8' Plant not glandularsticky at maturity; inflorescence clubshaped, often ± enclosed by leaves at maturity; spikelets laterally compressed ..... TUCTORIA
6' Leaf blade and sheath clearly differentiated; stem internodes generally hollow; ligules generally present
9. Basal or subterranean internodes swollen, bulb or cormlike
10. Inflorescence spikelike, cylindric or ovoid, branches not evident; glumes winged ..... Phalaris aquatica
10' Inflorescence paniclelike, open with evident branches; glumes not winged
11. Sheath open; glumes ± enclosing florets; lower lemma awns bent, twisted ..... ARRHENATHERUM (2)
11' Sheath closed to near tip; glumes = lowest floret; lower lemma awns generally 0 or awns straight, untwisted ..... MELICA
9' Basal or subterranean internodes not swollen, not bulb or cormlike
12. Robust perennial herb, generally 1.5–7 m; stem 0.5–3 cm diam, tough, hardened to woody, generally persisting; inflorescence terminal, often conspicuously plume or fanlike ..... Group 1
12' Low annual to midsized perennial herb, generally < 1.5 m; stem generally < 5 mm wide, strictly herbaceous, generally dying back annually; inflorescence axillary, terminal, or both, but not conspicuously plume nor fanlike
13. Plants generally < 15 cm; mature inflorescence not clearly exceeding leaves, often ± enclosed in upper sheath
14. Floret 1; lemma 1veined ..... CRYPSIS
14' Florets 2+; lemma >= 3veined
15. Lemma awn 0
16. Inflorescence subtended by 5–10 bristles; spikelets 1–2 mm; florets 2 ..... Pennisetum clandestinum
16' Inflorescence not subtended by bristles; spikelets 6–10 mm; florets 3–5 ..... SCLEROCHLOA
15' Lemma awns 1 or 3
17. Lemma 3lobed, conspicuously ciliate; upper florets 3awned ..... BLEPHARIDACHNE
17' Lemma 2lobed or tapering to awn
18. Glumes 6–9 mm, > lemma; lemma 2lobed ..... DASYOCHLOA
18' Glumes 2–4 mm, < lemma; lemma tapering to point ..... MUNROA
13' Plants generally >> 15 cm; mature inflorescence clearly exceeding upper leaves
19. Spikelets 1–2 per inflorescence
20. Glumes < lowest floret; awns (if present) not twisted, nor bent ..... Brachypodium distachyon
20' Glumes > lowest floret; awns twisted and bent ..... Danthonia unispicata
19' Spikelets few to many in a welldeveloped inflorescence
21. Spikelets subtended by 1+ bristles, sterile branches, or long, silky hairs > spikelet
22. Spikelets subtended by long, silky hairs from their bases, rachis joints, or pedicels
23. Spikelets dissimilar, sessile bisexual, stalked sterile ..... BOTHRIOCHLOA
23' Spikelets similar, bisexual ..... IMPERATA
22' Spikelets subtended by 1 or more generally stiff bristles or sterile branches
24. Bristles shortstiffhairy ..... SETARIA
24' Bristles scabrous to longciliate
25. Inflorescence paniclelike, branches 2–7 ..... ANDROPOGON
25' Inflorescence spikelike, dense, cylindrical ..... PENNISETUM
21' Spikelets not subtended by bristles or by long, silky hairs
26. Glume and/or lemma bodies covered with long, silky hairs
27. Inflorescence dense, ovoid or oblong, headlike; spikelets 1flowered ..... LAGURUS
27' Inflorescence open, branching evident; spikelets 2flowered
28. Spikelets paired on one side of a slender rachis ..... Digitaria californica
28' Spikelets single on ends of short capillary branches
29. Annual or shortlive perennial herb without stolons or rhizomes; upper floret compressed sidetoside; naturalized, disturbed areas, slopes, Outer North Coast Ranges, San Joaquin Valley, s Central Coast, Outer South Coast Ranges, South Coast, Western Transverse Ranges, Peninsular Ranges ..... MELINIS
29' Perennial herb from stolons or rhizomes; upper floret compressed fronttoback; native, sandy soils, dunes, e South Coast, Desert ..... Panicum urvilleanum
26' Glumes and lemma bodies glabrous to shorthairy
30. Glumes or lemma (perhaps only in a unisexual spikelet) with 3–9 awns or awnlike segments (lateral awns sometimes << than central 1)
31. Lemma awns 9, plumose ..... ENNEAPOGON
31' Lemma awns 0–3, not plumose
32. Lower glume with (2)3–9 awns or awnlike segments
33. Spikelets 1–flowered ..... Muhlenbergia alopecuroides
33' Spikelets 2–5 flowered
34. Annual; spikelets 1 per node ..... AEGILOPS
34' Perennial herb; spikelets 2(3–4) per node ..... Elymus multisetus
32' Lower glume awn 0 or 1
35. Spikelets 1flowered ..... ARISTIDA
35' Spikelets 2–severalflowered
36. Inflorescence open, paniclelike; spikelets pistillate ..... SCLEROPOGON (2)
36' Inflorescence 1–many racemelike or spikelike 1° branches; spikelets bisexual ..... BOUTELOUA
30' Glume or lemma awns 0–2
37. Spikelets generally dorsally compressed (cylindrical); florets 2, lower sterile or staminate, often reduced to sterile lemma, upper floret bisexual; glume and fertile lemma texture noticeably dissimilar; spikelets breaking apart below the glumes, falling singly or in pairs with segments of inflorescence axis attached ..... Group 2
37' Spikelets generally laterally compressed or cylindric; florets 1–many, if > 1, lower one(s) generally fertile, upper reduced and sterile; glume and fertile lemma texture generally similar; spikelets generally breaking apart above glumes and between florets or floret clusters
38. Plants bearing markedly dissimilar spikelets in the same or separate inflorescences
39. Spikelets unisexual ..... SCLEROPOGON (2)
39a. Terrestrial perennial herb to 20 cm; creosote scrubland ..... SCLEROPOGON
39a' Aquatic annual 1–1.5 m; cultivated fields and adjacent ditches ..... [ZIZANIA]
39' Spikelets bisexual or sterile
40. Inflorescence spikelike
41. Stem internodes solid; spikelets sessile ..... HILARIA
41' Stem internodes hollow; central spikelet sessile, laterals stalked (except in Hordeum vulgare) ..... HORDEUM
40' Inflorescence paniclelike, open to dense
42. Lemma awn 0; spikelets in groups of 7 (1 fertile + 6 sterile) ..... Phalaris paradoxa
42' Lemma awned; spikelets paired or in pendant clusters
43. Inflorescence paniclelike with drooping clusters of 1 fertile spikelet and 1–3 sterile ones; spikelet clusters falling as 1 unit ..... LAMARCKIA
43' Inflorescence headlike or cylindric, spikelets generally paired; spikelets falling separately ..... CYNOSURUS
38' Plants bearing similar spikelets, differing only in size and degree of maturity
44. Spikelets sessile or stalked on an unbranched central axis ..... Group 3
44' Spikelets attached to 1° or 2° branches (dissection may be needed to reveal branches)
45. Inflorescence a series of 2 or more digitate, racemelike, clusters, or whorls of 1° branches ..... Group 4
45' Inflorescence muchbranched, 2° or 3° branching evident
46. Spikelets 1flowered ..... Group 5
46' Spikelets 2–manyflowered (sterile florets reduced to small scales or hairy, awllike rudiments)
47. Spikelets 2–8 per node ..... ELYMUS
47' Spikelets 1 per node
48. Spikelets unisexual; plants dioecious
49. Leaf tips prowshaped; lemma base with cottony or cobwebby tuft of hairs ..... POA
49' Leaf tips flat; lemma bases glabrous to scabrous
50. Plants rhizomatous; lemma glabrous, veins 9–11, inconspicuous ..... DISTICHLIS (2)
50' Plants densely tufted; lemma scabrous, veins (3)5(7) ..... Festuca kingii
48' Spikelets bisexual
51. Fertile florets 2+ (occasionally 1 in Dissanthelium)
52. Lemma veins generally (3)5–several, sometimes very faint ..... Group 6
52' Lemma veins 3, generally prominent (laterals sometimes near margins)
53. Glumes > florets; florets 2(3) – Channel Islands only ..... DISSANTHELIUM
53' Glumes < upper florets; florets 3–many
54. Lemma veins glabrous ..... ERAGROSTIS
54' Lemma veins hairy, at least below
55. Leaf blade margin white; lemma awn 0.5–2.5 mm; stigmas white ..... ERIONEURON
55' Leaf blade margin green; lemma awn 0; stigmas purple ..... TRIDENS
51' Fertile floret 1
56. Spikelet breaking below glumes; lower floret bisexual, awn 0; upper floret staminate, awned ..... HOLCUS
56' Spikelet breaking above glumes; staminate or sterile floret(s) below fertile one (sometimes << fertile and easily overlooked)
57. Fertile floret generally awned
58. Perennial herb; nodes green or strawcolored; spikelets breaking apart below lowest floret ..... ARRHENATHERUM (2)
58' Annual; nodes purpleblack; spikelets breaking apart above lowest floret ..... VENTENATA
57' Fertile floret awn 0
59. Lower florets reduced to sterile lemma < 1/2 fertile floret ..... PHALARIS
59' Lower staminate or sterile florets >= fertile one
60. Spikelets strawcolored or brown at maturity; stamens 2–3; auricles 0 (except in Anthoxanthum aristatum, A. odoratum) ..... ANTHOXANTHUM
60' Spikelets green or purplish at maturity; stamens 3 or 6; auricles ciliate ..... EHRHARTA Group 1: Robust perennial herb; stem generally 1.5+ m, 0.5+ cm diam
1. Stem muchbranched above base ..... [PHYLLOSTACHYS]
1' Stem not branched above base (except inflorescence)
2. Leaves predominantly basal
3. Stem internodes hollow; spikelets unisexual (pls generally pistillate) ..... CORTADERIA
3' Stem internodes solid; spikelets bisexual ..... Stipa mauritanica
2' Leaves well distributed along stems
4. Inflorescence branches and spikelets glabrous
4a. Glumes 0 or vestigial  inflorescence branches unisexual, spikelets remaining intact until harvested ..... [ZIZANIA]
4a' Glumes present
5. Inflorescence spikelike (branched below) ..... Elymus condensatus
5' Inflorescence paniclelike ..... SORGHUM
4' Inflorescence branches and/or spikelets hairy
6. Stem internodes solid; spikelets paired, one or both stalked
7. Spikelets unequally stalked; inflorescence axis remaining intact at maturity ..... IMPERATA
7' 1 spikelet sessile, 2nd stalked; inflorescence axis breaking apart at maturity, segments with spikelets attached ..... SACCHARUM
6' Stem internodes hollow; spikelets 1 per node
8. Spikelet axis glabrous; lemma densely hairy ..... ARUNDO
8' Spikelet axis silkyhairy; lemma glabrous ..... PHRAGMITES Group 2: Spikelets dorsally compressed, breaking apart below glumes; glumes and fertile lemma of dissimilar texture
1. Glumes leathery to hardened (at least in sessile spikelets), ± equal, 1 or both generally > upper floret (except awns); fertile and sterile lemmas generally translucent
2. Spikelets 1 per node, subtended by a hairy bristle ..... ANDROPOGON
2' Spikelets 2 or 3 per node, 1 sessile and 1 (2) stalked
3. Terminal spikelets per branch in 3s, 1 sessile and 2 stalked ..... SORGHUM
3' Terminal spikelets per branch in 2s, 1 sessile and 1 stalked
4. Inflorescence unbranched, racemelike ..... HETEROPOGON
4' Inflorescence branched, paniclelike
5. Inflorescence internodes and spikelet stalks with a translucent longitudinal groove; lowest pair of spikelets per raceme fertile ..... BOTHRIOCHLOA
5' Inflorescence internodes and spikelet stalks without a translucent longitudinal groove; lowest pair of spikelets per raceme staminate ..... HYPARRHENIA
1' Glumes membranous, flexible, lower glume generally < upper (0), upper glume <= upper floret; sterile lemma membranous and resembling upper glume, fertile lemma leathery to hardened (membranous in Digitaria)
6. Inflorescence spikelike; spikelet bases ± embedded in 1 side of flattened, thickened axis ..... STENOTAPHRUM
6' Inflorescence paniclelike or a series of paired, digitate, or racemose branches; spikelets not embedded, on 1 or more sides of rounded, unthickened axes
7. Spikelet subtended by a cup or ringlike structure ..... ERIOCHLOA
7' Spikelet not subtended by cup or ringlike structure
8. Ligule 0, at least on upper leaves ..... ECHINOCHLOA
8' Ligule present
9. Inflorescence a series of digitate or racemelike branches
10. Fertile floret membranous, flexible at maturity ..... DIGITARIA
10' Fertile floret leathery to hardened, rigid at maturity ..... PASPALUM
9' Inflorescence paniclelike
11. Fertile lemma thin, flexible; lower glume minute or 0 ..... Digitaria californica var. californica
11' Fertile lemma ± thick, rigid; lower glume welldeveloped ..... PANICUM Group 3: Inflorescence solitary, spikelike or racemelike; spikelets sessile or stalked
1. Some or all spikelets stalked
2. Spikelets 3 per node, sessile and stalked (or only stalk remaining after upper spikelet has fallen); inflorescence spikelike
3. Stem internodes solid; auricles 0; central spikelet shortstalked, laterals sessile; glumes awned ..... HILARIA
3' Stem internodes hollow; auricles present or 0; central spikelet sessile, laterals stalked; glumes awnless ..... HORDEUM
2' Spikelets 1 per node, stalked; inflorescence racemelike
4. Lemma veins prominent, parallel; palea keeled, winged on lower 1/2 ..... PLEUROPOGON
4' Lemma veins converging at tip; palea not winged
5. Glumes >= florets, ± enclosing them ..... DANTHONIA (2)
5' Glumes ± = lower florets only
6. Spikelet axis thickened, falling with florets; lemma ± circular in ×section ..... DESMAZERIA
6' Spikelet axis not thickened, not falling with florets; lemma flattened
7. Upper leaf sheaths closed; lemma tips generally 2forked or 2lobed ..... BROMUS
7' Upper leaf sheaths open; lemma tips obtuse or acute
8. Upper glume veins (3)5–9; palea keeled, ciliate ..... BRACHYPODIUM (2)
8' Upper glume veins 3(5); palea glabrous or hairy, but not keeled, nor ciliate ..... FESTUCA (2)
1' All spikelets sessile or nearly so (upper spikelets sometimes stalked in Scribneria)
9. Glume 1 (except in uppermost spikelets; 0 in Elymus californicus)
10. Stem internodes hollow; inflorescence axis remaining intact at maturity; spikelets breaking apart above glumes; lemma veins 5 ..... FESTUCA (2)
10' Stem internodes solid; inflorescence axis breaking apart at maturity, spikelets falling with axis segments; lemma veins 3 ..... HAINARDIA
9' Glumes 2
11. Spikelet bases ± embedded in cavities or pits in thickened inflorescence axis
12. Perennial herb from stolons or rhizomes; spikelets attached to one side of flattened inflorescence axis ..... STENOTAPHRUM
12' Annual; spikelets attached to both sides of rounded inflorescence axis
13. Spikelets awnless ..... PARAPHOLIS
13' Spikelets awned
14. Glumes awned; lemmas awnless; florets 2–5 ..... AEGILOPS
14' Glumes awnless; lemma awned; floret 1 ..... SCRIBNERIA
11' Spikelet bases not embedded in cavities or pits of thickened inflorescence axis
15. Spikelets borne on one side of inflorescence axis; lemma veins 3 ..... BOUTELOUA
15' Spikelets 2ranked; lemma veins 5–9
16. Spikelets 2–8 per node ..... ELYMUS (2)
16' Spikelets 1 per node
17. Lemma keels ciliate ..... SECALE
17' Lemma keels (if present) not ciliate
18. Glumes > florets and generally enclosing them (except awns and lemma teeth) ..... DANTHONIA (2)
18' Glumes < florets
19. Fertile floret 1, subtended by 2 sterile florets ..... Ehrharta longiflora
19' Fertile florets 2+, sterile florets above the fertile ones
20. Auricles 0 ..... BRACHYPODIUM (2)
20a. Palea keels strongly ciliate; awns (when present) straight; nodes generally pubescent ..... BRACHYPODIUM
20a' Palea keels not ciliate; awns twisted, bent; nodes glabrous ..... [GAUDINIA]
20' Auricles present
21. Glumes and lemma backs rounded ..... ELYMUS (2)
21' Glumes and lemmas keeled
22. Perennial herb; lemma awns 1–6 mm ..... AGROPYRON
22' Annual; lemma awns to (0)4 cm ..... TRITICUM Group 4: Inflorescence branches digitate, racemelike, clustered, or in whorls; no further branching evident
1. Inflorescence branches digitate or clustered at tip of inflorescence axis
2. Glume and lemma awns 0
3. Perennial herb; floret 1; internal spikelet axis extended behind palea as a slender bristle, rarely bearing a sterile floret ..... CYNODON
3' Annual or shortlived perennial herb; florets 2+; internal spikelet axis not extended behind palea ..... ELEUSINE
2' Glumes and/or lemmas awned
4. Spikelets laterally compressed or cylindric, but not keeled; upper glume awn 0; tip of inflorescence branch not extending beyond last spikelet ..... CHLORIS (2)
4' Spikelets strongly keeled; upper glume awned; tip of inflorescence branch extending beyond last spikelet ..... DACTYLOCTENIUM
1' Inflorescence branches racemelike, 1+ per node along a central, unbranched axis, or in whorls
5. Floret 1 per spikelet; plants of coastal marshes and wet places ..... SPARTINA
5' Florets 2+ per spikelet (except basal spikelet per branch in Bouteloua aristidoides); plants of various habitats
6. Fertile floret 1 per spikelet
7. Inflorescence branches 2+ per node ..... CHLORIS (2)
7' Inflorescence branches 1 per node
8. Spikelet laterally compressed; lowest floret bisexual ..... BOUTELOUA
8' Spikelet dorsally compressed; upper floret bisexual ..... ECHINOCHLOA
6' Fertile florets 2+ per spikelet
9. Lemma 3veined, sometimes appearing 1veined ..... LEPTOCHLOA
9' Lemma 5–severalveined
10. Upper glume 3veined ..... FESTUCA
10' Upper glume 7veined ..... SCLEROCHLOA Group 5: Inflorescence paniclelike, open and spreading to compact, cylindrical or headlike; spikelets 1flowered
1. Stem nodes purpleblack; floret staminate ..... VENTENATA
1' Stem nodes green or strawcolored; floret bisexual
2. Glumes 0; palea 3veined; plants of wet sites ..... LEERSIA
2' Glumes 1 or 2; palea, when present, 2veined; plants generally of drier sites (except Oryza and some Phalaris)
3. Lower glume awns 2 ..... Muhlenbergia alopecuroides
3' Lower glume awn 0 or 1
4. Spikelets ± round, overlapping in 2 rows on 1 side of inflorescence branch; glumes winged, body transversely wrinkled ..... BECKMANNIA
4' Spikelets not round, nor overlapping in 2 rows; glumes not winged, body smooth or veined, but not transversely wrinkled
5. Glumes ciliatekeeled
6. Glumes united at base; lemma awned; palea 0 ..... ALOPECURUS
6' Glumes separate at base; lemma awnless; palea present ..... PHLEUM
5' Glumes glabrous to sparsely hairy, but not ciliatekeeled
7. Glumes unequal, tapering to a long point, ± swollen at base ..... GASTRIDIUM
7' Glumes equal or unequal, but not tapering to long points, not swollen at base
8. Glumes keeled, often winged; floret subtended by a membranous flap or tuft of hairs ..... PHALARIS
8' Glumes generally rounded, not winged; floret not subtended by a flap or tuft of hairs
9. Lemma generally hardened at maturity, margins generally overlapping and enclosing palea and grain; grain hardened, round in ×section; callus welldeveloped, blunt or sharppointed
10. Stem internodes ± solid; lemma veins 3, awns generally straight; ligule of hairs or basal membrane longciliate ..... ARISTIDA
10' Stem internodes hollow; lemma veins 3–7, awns generally bent 1–2 ×; ligule generally membranous ..... STIPA
9' Lemma and grain membranous or firm, but not hardened, generally flattened; callus not especially welldeveloped
11. Spikelet axis extended beside or above floret as a glabrous or hairy stub or bristle
12. Spikelets breaking apart below glumes at maturity; stamens 1–2 ..... CINNA
12' Spikelets breaking apart above glumes at maturity; stamens 3
13. Annual; callus glabrous to sparsely hairy ..... APERA
13' Annual or perennial herb from stolons or rhizomes; callus hairy
14. Inflorescence dense, cylindrical; spikelets 12–14 mm; lemma awn 0 ..... AMMOPHILA
14' Inflorescence open, paniclelike; spikelets 2–4(11) mm; lemma awn 0.5–17 mm ..... CALAMAGROSTIS
11' Spikelet axis not extended beside or above floret
15. Plants of flooded fields and in adjacent ditches; stamens 6 ..... ORYZA
15' Plants terrestrial; stamens 1 or 3
16. Glumes with welldeveloped awns (except Polypogon viridis); spikelets breaking apart below glumes ..... POLYPOGON
16' Glumes acute, acuminate, or awntipped; spikelets breaking apart above glumes
17. Lemma vein 1, awn 0; leaf sheaths generally ciliate at tip; seed ejected from grain at maturity ..... SPOROBOLUS
17' Lemma vein 3 or 5, awn present or 0; leaf sheaths not ciliate at tip; seed remaining within grain at maturity
18. Lemma veins 5(3), faint; palea generally 0 or << lemma ..... AGROSTIS
18' Lemma veins 3, generally obvious; palea generally welldeveloped ..... MUHLENBERGIA Group 6: Inflorescence paniclelike, open and spreading to compact, cylindrical or headlike; fertile florets 2+
1. One or both glumes >= lowest floret, sometimes enclosing all of them
2. Spikelet length ± = width; glumes, lemma papery to translucent, inflated, at right angles to spikelet axis ..... BRIZA
2' Spikelet longer than wide; glumes, lemma not papery to translucent, nor at right angles to axis
3. Glumes of 2 kinds, lower linear to lanceolate, upper 3–4× wider than lower when spread flat; spikelet axis breaking below glumes ..... SPHENOPHOLIS
3' Glumes similar in shape, equal in length or not; spikelets breaking above glumes and between florets (except Trisetum)
4. Lemma awnless
5. Spikelet axis extended beyond bisexual florets as a slender, hairy bristle, sometimes with a reduced floret at its tip
6. Spikelets shiny; glume keels minutely ciliate; axis internodes < 1 mm ..... KOELERIA (2)
6' Spikelets not shiny; glume keels not ciliate; axis internodes 1.5–2 mm ..... TRISETUM (3)
5' Spikelet axis not extended beyond bisexual florets
7. Perennial herb; palea veins swollen at base; spikelets 7–15 mm ..... [Danthonia decumbens]
7' Annual; palea veins not swollen at base; spikelets 4.5–7 mm ..... SCHISMUS
4' Lemma awned (sometimes awnless in Avena sativa)
8. Spikelets 15–50 mm ..... AVENA
8' Spikelets < 15(20) mm
9. Lemma awned at or below middle
10. Annual; lemma tip 2lobed; spikelet axis not extended beyond upper floret ..... AIRA
10' Perennial herb (except Deschampsia danthonioides); lemma tip 2–4 toothed at truncate tip; spikelet axis generally extended beyond upper floret
11. Leaves generally basal, blades 1–3 mm wide; spikelet axis >= 0.75 mm beyond upper floret, generally densely hairy ..... DESCHAMPSIA
11' Leaves generally cauline, blades 3–7 mm wide; spikelet axis inconspicuous beyond upper floret, ± 0.5 mm, generally glabrous ..... VAHLODEA
9' Lemma awned at or near tip or between 2 teeth
12. Spikelet axis clearly hairy ..... TRISETUM (3)
12' Spikelet axis ± glabrous
13. Lemma hairy, hairs in 1+ transverse rows ..... RYTIDOSPERMA
13' Lemma glabrous or if hairy, hairs on margins or evenly distributed ..... DANTHONIA
1' Lower glume < lowest floret, never enclosing 2 or more florets
14. Lemma awnless
15. Lemma veins ± prominent, equallyspaced, parallel
16. Upper glume 1veined; leaf sheath closed to near top ..... GLYCERIA
16' Upper glume 3veined; leaf sheath open
17. Rhizomes 0; lemma faintly 5veined; plants of saline or alkaline soils ..... PUCCINELLIA
17' Rhizomes present; lemma distinctly 7–9veined; plants of freshwater sites ..... TORREYOCHLOA
15' Lemma veins not especially prominent, converging at tip
18. Leaf tips prowshaped; callus and/or lemma base generally cobwebbyhairy ..... POA
18' Leaf tips flat; callus or lemma base glabrous to scabrous
19. Spikelet axis segments thickened, falling with florets; lemma ± round in ×section ..... DESMAZERIA
19' Spikelet axis segments not thickened, not falling with florets; lemma flattened
20. Lower glume broadly translucent distally and along margins; uppermost florets vestigial, densely clustered, sometimes appearing as a clubshaped rudiment; leaf sheaths closed ..... MELICA (2)
20' Lower glume generally membranous or narrowly translucent near tip or margins only; uppermost florets, if vestigial, not densely clustered, clubshaped rudiment 0; leaf sheaths open or closed
21. Leaf sheath closed to near top; lemma tip 2toothed; spikelets generally 15–70 mm ..... BROMUS (2)
21' Leaf sheath open for at least 1/2 its length; lemma tip tapering to a point; spikelets generally 3.5–12(18) mm ..... FESTUCA (2)
14' Lemma awned
22. Inflorescence often dense, cylindric, spikelike, or more open in full flower; spikelets shiny, palea colorless ..... KOELERIA (2)
22' Inflorescence branching evident; spikelets not especially shiny; palea brown or green, at least along veins
23. Spikelets in dense, 1sided clumps on distal portions of panicle branches; lemma keels stiffciliate ..... DACTYLIS
23' Spikelets not densely clumped at ends of panicle branches; lemma keels not stiffciliate
24. Lower glume broadly translucent distally and along margins; uppermost florets vestigial, densely clustered, sometimes appearing as a clubshaped rudiment; leaf sheaths closed ..... MELICA (2)
24' Lower glume generally membranous or narrowly translucent near tip or margins only; uppermost florets, if vestigial, not densely clustered, clubshaped rudiment 0; leaf sheaths open or closed
25. Spikelet axis hairy, extended beyond upper florets; upper glume >= lowest floret ..... TRISETUM (3)
25' Spikelet axis generally glabrous, not extended beyond upper florets; upper glume < lowest floret
26. Leaf sheath closed; spikelet generally 1+ cm; lemma tip 2toothed; ovary tip hairy ..... BROMUS (2)
26' Leaf sheath open for at least 1/2 its length (except in Festuca rubra); spikelet generally < 1 cm; lemma tip entire, occasionally minutely 2toothed; ovary tip glabrous or hairy ..... FESTUCA (2)
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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/eflora/ [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.
