A N F Keys
Genera Keys of
1 Palea > 1.0 mm long and > 1/2 lemma, the lemma minutely 3-toothed .. Agrostis gigantea [pics]
1' Palea absent or present but only to 0.3 mm long and < 1/5 lemma, the lemma minutely 5-toothed
2 Panicle mostly compact, the longest lower branches to 23 mm long; anthers 0.3−0.6 mm long; plants sometimes producing stolons with leaves densely tufted at base of each plantlet .. Agrostis exarata
2' Panicle mostly open with ascending branches, the longest lower branches mostly > 25 mm long; anthers 0.7−1.8 mm long; plants strictly rhizomatous and not producing stolons .. Agrostis pallens
1 Perennials; blades of basal leaves highly reduced, < 4.5 mm long; ligule of hairs 0.3−0.5 mm long; branches of panicle lacking pulvinus at base; lemma awns subequal, central awns 19−31.5 mm long, lateral awns 16−28 mm long .. Aristida adscensionis [pics]
1' Annuals; blades of basal leaves at least 20 mm long; ligule of hairs 0.4−1 mm long; major branches of panicle having pulvinus at base; lemma with central awn longer, central awns (7−)8−12(−15) mm long, lateral awns 7.4−10.6 mm long .. Aristida purpurea var. parishii
1 Blades rough along veins, some blades on plant 20−31 mm wide; spikelet not breaking above glumes and permanently retaining florets, callus glabrous; swelling beneath glumes 1.5−2 mm wide .. Avena sativa [pics]
1' Blades not rough along veins, always < 16 mm wide; spikelet breaking above glumes and florets falling separately, callus hairy
2 Swelling beneath glumes 0.4−0.8 mm wide; lemma forks 2−6 mm long .. Avena barbata [pics]
2' Swelling beneath glumes 1.1−1.4 mm wide; lemma forks 0.7−1.7 mm long .. Avena fatua [pics]
1 Lemmas strongly keeled, spikelets strongly flattened
2 Lemma lacking awn or awn only to 3.5 mm long .. Bromus catharticus var. catharticus [pics]
2' Awn attached to tip of lemma 4+ mm long
3 Leaf sheath closed to about midpoint, distinctly pilose; upper glume shorter than the lowest lemma .. Bromus carinatus var. carinatus [pics]
3' Leaf sheath closed most of length, glabrous to pilose-pubescent; upper glume about as long as the lowest lemma .. Bromus arizonicus
1' Lemmas rounded over midvein and not strongly keeled, spikelets ± cylindric or only slightly compressed
4 Perennials; leaves with blades often 10+ mm wide, short, ± bronze ligules, and well-developed lobes (auricles); awn arising close to lemma tip; stamens 3, exserted, with anthers 4−5 mm long .. Bromus pseudolaevipes [pics]
4' Annuals; leaves with blades < 10 mm wide and ligules not bronze, lacking auricles; awn arising 1+ mm from lemma tip; stamens 2−3, included and rarely exposed, with anthers mostly < 1 mm long (maximum 2.2 mm long in B. berteroanus, which sometimes also has short auricles)
5 Awns of lemma distinctly bent (geniculate) and strongly twisted below bend, lemma tips 2−5 mm long and sometimes awnlike .. Bromus berteroanus
5' Awns of lemma straight to curved, never distinctly bent, lemma tips never awnlike
6 Lemma tip entire to short 2-toothed
7 Upper glume 8.5−10 mm long; lemmas 9.5−11.2 mm long, awns 10.5−16 mm long .. Bromus arenarius
7' Upper glume 7−8 mm long; lemmas 7.5−9.3 mm long, awns 4.5−7.2 mm long .. Bromus hordeaceus [pics]
6' Lemma tip deeply 2-toothed, the tips mostly > 1.5 mm long
8 Panicle dense, erect, with spikelets having straight, stiff stalks
9 Stems (culms) glabrous or essentially so; upper glume 13−15 mm long; lemma 17−21 mm long with awn 20−25 mm long .. Bromus madritensis subsp. madritensis [pics]
9' Stems (culms) pubescent with backward-pointing hairs; upper glumes 7.5−12.5 mm long; lemmas 8.5−16 mm long with awn (8−)15−20 mm long .. Bromus madritensis subsp. rubens [pics]
8' Panicle open, the branches spreading or drooping
10 Lower glume 12−25 mm long; lemma 18−35 mm long with awn 30−62 mm long .. Bromus diandrus [pics]
10' Lower glume 5−11 mm long
11 Spikelets 1−14 on inflorescence branchlet; upper glume 7−9.5 mm long; lemma 12−14 mm long with awn 10−17 mm long .. Bromus tectorum [pics]
11' Spikelets 1(3) on inflorescence branchlet; upper glume 14−17 mm long; lemma 20−22 mm long with awn 22−29 mm long .. Bromus sterilis
NB. Bromus maritimus (Piper) Hitchc. was collected by Peter Raven near the intersection of Mulholland Drive and Beverly Glen Boulevard, a partially residential area, and the area is now maintained so that the species has not been rediscovered there, although it may be expected more likely at sites along Pacific Coast Highway.
1 Shoots highly branched commonly with > 10 leaves and inflorescences; leaf sheath pilose on margins; blades 10−50 × 1−3 mm, commonly abscising from sheath (appearing bladeless) .. Crypsis vaginiflora
1' Shoots not typically branched above base with 5−10 cauline leaves; leaf sheath glabrous on margins; blades 20−100 × 2−6 mm, not abscising from sheath .. Crypsis schoenoides [pics]
1 Spikelets generally 3 per node along inflorescence branch; upper glume about equal to spikelet and lower glume absent or reduced to a membranous scale or rim; achene 1.4−1.5 mm long .. Digitaria ischaemum [pics]
1' Spikelets generally 2 per node along inflorescence branch; upper glume up to midpoint of spikelet and lower glume 0.2−0.8 mm long; achene 2−2.2 mm long .. Digitaria ciliaris var. ciliaris [pics]
NB. Herbarium records indicate that Digitaria sanguinalis (L.) Scop. has been collected near the borders of the range and is known as a weed in suburban West Hills, so probably this species will eventually be included if found established away from urbanized situations. This species should have a keeled leaf sheath, and both surfaces of blades should have abundant long hairs with swollen bases. Digitaria sanguinalis generally has two spikelets per node, and the hairs on the glumes and lemmas are short or absent, not conspicuous and pilose, as seen in D. ciliaris.
1 Mat-forming, procumbent to decumbent plants of salt marsh; blades < 10 mm long and strongly keeled, later having opposite to subopposite lateral shoots; inflorescences difficult to find, terminal on several-leaved branchlets and spikelets with 3−5 florets .. Distichlis littoralis [pics]
1' Spreading to ascending plants of haline, brackish, or freshwater margins; blades 15−100 mm long and strongly inrolled, never exhibiting paired lateral shoots; inflorescences relatively easy to observe, elevated on peduncles and spikelets with (4−)7−12(−20) florets .. Distichlis spicata [pics]
1 Inflorescence with only 1 spikelet per node
2 Spikelets awned, glume awns (0)1−5(−9) mm long and lemma awns (5−)10−25(−35) mm long; florets (1−)2−4(−6) per spikelet .. Elymus glaucus subsp. glaucus [pics]
2' Spikelets lacking awns; florets 6−12 per spikelet .. Elymus ponticus [pics]
1' Inflorescence in which 2 or more spikelets occur at many or all nodes
3 Spikelets with long awns or awnlike tips on glumes and lemmas
4 Annuals; spikelets 2−3(−4) per node; glume "awns" not branched, but pairs of glumes fused on outer side of spikelet .. Elymus caput-medusae [pics]
4' Perennials but not rhizomatous; spikelets strictly 2 per node; glumes separate and each glume awn split into unequal divisions .. Elymus multisetus
3' Spikelets lacking glume awns and having lemma awns only to 4 mm long, awn not exceeding half the length of the lemma
5 Robust, dense clump (bunchgrass) often several meters across, to 250 cm tall and with broad, tough cauline leaves; spikelets 6−35 per node; lemma body 7−11 mm long .. Elymus condensatus [pics]
5' Clonal perennials with shoots spaced along creeping rhizome, shoots ± erect, generally < 100 cm tall; spikelikes 2 per node at midpoint but at some nodes with 3 spikelets and other nodes only 1 spikelet; lemma 5−7.5 mm long .. Elymus triticoides subsp. triticoides [pics]
1 Mat-forming by stolons and rooting at nodes in wet soil; blades < 25 mm long; axillary pulvini in inflorescence absent .. Eragrostis hypnoides
1' Roots only at plant base, stolons absent; blades mostly > 30 mm long; axillary pulvini present in inflorescence
2 Palea keels prominently short-ciliate; lemmas with craterlike glands along keel (also below nodes along the stem) ......Eragrostis cilianensis
2' Palea keels either smooth or minutely scabrous; shoots and inflorescence lacking craterlike glands
3 Stems and inflorescence axes with ring of glandular tissue below the nodes often shiny or yellowish .. Eragrostis barrelieri [pics]
3' Stems and inflorescence axes without ring of glandular tissue below the nodes
4 Axillary pulvinus of lateral inflorescence branch with hairs to 5 mm long; spikelets mostly with 9−13 florets .. Eragrostis pectinacea var. pectinacea
4' Axillary pulvinus of lateral inflorescence branch glabrous; spikelets with 5−9 florets .. Eragrostis mexicana subsp. virescens
NB. Eragrostis cilianensis (All.) Janch. was included in previous treatments but currently is excluded because the only known specimens were collected out of range in Westwood Village, but it should be expected in range.
1 Inflorescence spikelike; glume 1 (= Lolium)
2 Glume shorter than spikelet .. Festuca perennis [pics]
2' Glumes nearly equal to the spikelet in length .. Festuca temulenta
1' Inflorescence paniclelike; glumes 2
3 Perennials; stamens 3
4 Sheath closed about 3 mm at base, ligule 0.4−1 mm long; lower glume 4.5−5.5 mm long, upper glume 5.5−6.2 mm long .. Festuca arundinacea [pics]
4' Sheath open to base, ligule < 0.5 mm long; lower glume 2.2−3.3 mm long; upper glume 3−3.8 mm long .. Festuca elmeri [pics]
3' Annuals; stamens typically 1 (= Vulpia)
4 Lower glume 0.7−2 mm long, < 1/2 upper glume .. Festuca myuros [pics]
4' Lower glume 2−4.5 mm long
5 Spikelet with (5−)7−12 florets, appearing dense with overlapping spikelets .. Festuca octoflora
5' Spikelet with 1−6 florets, not appearing dense
6 Inflorescence lateral branches and solitary spikelets widely spreading to reflexed by axillary pulvini .. Festuca microstachys [pics]
6' Inflorescence lateral branches appressed to erect at mature and lacking axillary pulvini .. Festuca bromoides
NB. For convenience, the tuft grasses Festuca pratensis (L.) Columbus & J. P. Smith (MEADOW FESCUE) and F. rubra L. (RED FESCUE) have not been described. These grasses are grown within range and certainly occur out of cultivation, i.e., where transported by storm runoff and are establish and cloning. Such cultivated tuft grasses often are of hybrid parentage, and frequently sterile, so that choosing materials for description would also be problematic.
The genus Festuca here is treated in a very broad sense to include Vulpia and Lolium.
1 Blades > 4 mm wide; leaf sheath glabrous and having well-developed lobes (auricles)
2 Glumes of central spikelet and inner glume of lateral spikelets long-ciliate; rachis breaking apart at maturity, rachis segments 1.5−3 mm long .. Hordeum murinum [pics]
3 Stalk of central floret 1.2−1.5 mm long; glumes of central floret > glumes of lateral florets; palea of central floret ± pilose to midpoint; anthers 0.2−0.6 mm long ......Hordeum murinum subsp. glaucum
3' Stalk of central floret 1 mm long; glumes of central floret < glumes of lateral florets; palea of central floret scabrous to midpoint; anthers 0.9−3 mm long ......Hordeum murinum subsp. leporinum
2' Glumes with fine, ascending short hairs; rachis not breaking apart at maturity, rachis segments 3−4.5 mm long .. Hordeum vulgare subsp. vulgare [pics]
1' Blades < 4 mm wide; leaf sheath pubescent to pilose and lacking auricles or to < 0.5 mm long (H. brachyanthemum)
4 Perennials; inflorescence breaking apart at maturity; glumes of lateral spikelets < 0.2 mm wide, not flattened and expanded near base .. Hordeum brachyantherum subsp. californicum
4' Annuals; inflorescence not breaking apart at maturity; glumes of lateral spikelets at least 0.3 mm wide, flattened and expanded above base
5 Inflorescence (including awns) narrow, generally < 8 mm wide; rachis segments > 1 mm long; awn on lemma of lateral spikelets absent
6 Rachis segments ca. 1.2 mm long; glumes of central spikelet 8−13 mm long; stalk of lateral spikelets ca. 0.3 mm long; glumes of lateral spikelets 6.5−9 mm long .. Hordeum depressum [pics]
6' Rachis segments 1.5−1.9 mm long; glumes of central spikelet 15−16 mm long; stalk of lateral spikelets 0.8−1 mm long; glumes of lateral spikelets 13.5−16 mm long .. Hordeum intercedens
5' Inflorescence (including awns) wider, generally > 8 mm wide; rachis segments < 1 mm long; awn on lemma of lateral spikelets > 2 mm long .. Hordeum marinum subsp. gussoneanum [pics]
Leptochloa P.
Beauv.
SPRANGLETOP
1 Blades of cauline leaves mostly 460−600 mm long and exceeding panicle; lower glume 1.5−2.8 mm long and upper glume 2.9−3.3 mm long; lemma fusiform, 3−3.5 mm long with a terminal awn 0.8−1.5 mm long, maturing smoky white .. Leptochloa fusca subsp. fascicularis [pics]
1' Blades of cauline leaves mostly 35−350 mm long, not concealing panicle; lower glume 1.1−1.3 mm long and upper glume 1.8−2.2 mm long; lemma elliptic, 2−2.6 mm long and lacking awn, maturing lead-colored (dark green) .. Leptochloa fusca subsp. uninervia [pics]
1 Inflorescence closed and narrowly cylindric, 170−200+ × 6−8 mm; spikelets 7.5−10 mm long, with 6−7 florets having 5 bisexual florets and 1 or 2 upper florets sterile or rudimentary; lower glume 5.2−7 mm long, lemmas 7−7.7 mm long .. Melica californica [pics]
1' Inflorescence open and lanceoloid to ovoid with flexible, spreading lateral branches, 200−300+ × 50−100 mm; spikelets 3.5−4.5 mm long, with 2(−3) florets and upper floret sterile or rudimentary; lower glume 2.2−3.3 mm long, lemmas 3.5−4 mm long .. Melica imperfecta [pics]
1 Annuals of barren ground on sandy and rocky slopes, often with purplish foliage and feathery inflorescences; awns slender, 10−22 mm long on lemma, purple aging light tan; cleistogamous spikelets hidden by several leaf sheaths at base of plant .. Muhlenbergia microsperma [pics]
1' Perennials of wet habitats
2 Clonal perennial herb with scaly rhizomes and leafy stolons from which arise shorter shoots, growing on waterfalls; blades 10−50(−70) × 1−2.5 mm; inflorescence a feathery, open panicle, 50 × 260 mm long, with spreading branches having a pulvinus at base .. Muhlenbergia asperifolia [pics]
2' Clump-forming, cespitose bunchgrass along creek beds, not clonal; blades 90−930 × 2−5 mm, often inrolled above midblade; inflorescence condensed and cylindric, 210−440 × 5−9 mm, on long peduncle .. Muhlenbergia rigens [pics]
1 Blades 45−570 × 4−12 mm; inflorescence paniclelike with 3−7(−11) spikelike branches 30−115 mm long; glumes 1 (lower glume absent); bottlebrushlike stigmas purple to burgundy; achenes ± compressed-round, 1.9−2.1 mm .. Paspalum dilatatum [pics]
1' Blades to 130 mm long; inflorescence with (1−)2(−3) spikelike branches; glumes 1(−2)
2 Plants in monospecific stands from creeping stolons; blades 2−3.5 mm wide; branches of inflorescence paired at top of peduncle and spreading to reflexed, 26−45 mm long; bottlebrush stigmas colorless to light yellow aging reddish brown; achene compressed-ovoid, ± 3 × 1.9−2.2 mm; margins of upper glume and lower lemma glabrous .. Paspalum vaginatum [pics]
2' Plants with stolons and rhizomes but mixed with other plant species; blades 2.5−8 mm wide; branches of inflorescence staggered near top of peduncle (spaced to 9 mm apart), (10−)13−65(−70) mm long; bottlebrush stigmas dark burgundy; achene compressed-ellipsoid to slightly obovoid, 2.2−2.4 × 1.1−1.4 mm; margins of upper glume and lower lemma ciliate .. Paspalum distichum
Pennisetum Rich.
FOUNTAIN GRASS
1 Creeping herbs cloning by rhizomes and stolons, forming a mat; blades lanceolate, 9−11.5 × ca. 2 mm; inflorescence typically absent, when present terminal on short lateral shoots in a highly reduced and concealed cluster of 2−4 spikelets; stamens long-exserted from tip of palea, filaments becoming 40−55+ mm long and prostrate on turf canopy .. Pennisetum clandestinum [pics]
1' Cespitose herb with many ascending stems at base; blades linear, mostly 200−700 mm long; inflorescence a conspicuous, bristle-bearing panicle terminal on a long peduncle (culm) bearing many spikelets; filaments radiating from panicle and only to 6 mm long
2 Blades stiffy U-shaped base-to-tip; panicle (80−)110−250 × 40−62 mm, initially purple-red but fading after flowering; spikelet with 2 florets, having 1 glume, 2 lemmas, and 1 palea (upper floret) .. Pennisetum setaceum [pics]
2' Blades eventually flat for most of length; panicle 40−115 × 40−60 mm, appearing pale yellow to tawny white; spikelet with 2 florets but only forming an upper fruit, having 2 glumes, 2 lemmas, and 1 or 2 paleae .. Pennisetum villosum [pics]
1 Perennials, forming many-stemmed clump from rhizomes, plants in flower commonly > 100 cm tall and with cauline leaves > 250 mm long; dense panicle mostly 80+ mm long .. Phalaris aquatica [pics]
1' Annuals, lacking rhizomes, plants in flower typically < 100 cm tall and with cauline leaves < 250 mm long; dense panicle < 80 mm long
2 Spikelets in groups of 5 or more, 1 fertile surrounded by others sterile, the group falling as a unit; glume of fertile spikelet having a prominent lobe; in fruit panicles 7−9 mm diameter .. Phalaris paradoxa [pics]
2' Spikelets solitary, all alike and fertile, each spikelet falling individually; glume of fertile spikelet lacking a prominent lobe; in fruit panicles typically 10+ mm diameter
3 Panicles ± ovoid, 15−50 mm long; spikelet with 2 short sterile lemmas > 2 mm long inside the glumes below the fertile lemma (= 2 sterile florets with 1 fertile floret); glumes 7−10 mm long, margins minutely serrate .. Phalaris canariensis
3' Panicles lanceoloid-cylindric, 10−75 mm long; spikelet with 1 short sterile lemma ca. 1 mm long; glumes mostly 4−5 mm long, margins minutely serrate but having larger, irregular teeth above midpoint .. Phalaris minor [pics]
NB. At least four other species of Phalaris should be expected in range, especially P. caroliniana Walter, for which good vouchers are required to include it in the flora.
1 Spikelets modified into bulblike structure, and each shoot having a bulbous base .. Poa bulbosa subsp. vivipara
1' Plants lacking bulblike structures
2' Perennials
3 Bunchgrasses densely tufted, growing in scrubland in shallow soil; panicle compact and congested, with 1−3 erect to ascending lateral branches per node; spikelets 5−8 mm long; lemma 3.5−6 mm long .. Poa secunda subsp. secunda [pics]
3' Plants loosely tufted generally along stolons, growing in shaded wetlands; panicle open and wispy with ca. 5 spreading lateral branches per node; spikelets 3−5 mm long; lemmas 2−3 mm long .. Poa palustris
1 Spikelets with awns on glumes and lemmas; panicle condensed; floret on short stalk
2 Rhizomatous perennials with shoots tufted along rhizome; stem internodes to 75 mm long; awns of glumes 1.5−2.9 mm long .. Polypogon interruptus [pics]
2' Annuals; stem internodes mostly 90−185 mm long; awns of glumes 4−8.5 mm long .. Polypogon monspeliensis [pics]
1' Spikelets lacking awns; panicle open with spreading lateral branches having a pulvinus at each base; floret subsessile .. Polypogon viridis [pics]
Schismus P.
Beauv.
MEDITERRANEAN GRASS
1 Blades sparsely pilose on upper surface to midpoint; spikelet with both glumes exceeding the uppermost lemma; lemma deeply 2-lobed, the lobes 0.6−1 mm long and acute to acuminate, palea always noticeably shorter than lemma (typically to base of lemma lobes); stigmas exserted sideways from spikelet .. Schismus arabicus [pics]
1' Blades with pilose hairs on upper surface only at base near collar; spikelet with the uppermost lemma the same or exceeding lower glume; lemma shallowly notched, the lobes < 0.3 mm long and broad, palea of lower floret equal to or slightly longer than lemma; stigmas erect within florets .. Schismus barbatus [pics]
Setaria P.
Beauv.
BRISTLE GRASS
1 Blades (2−)5−12(−17) mm wide; panicle (including bristles) 25−85 × 11−15 mm, the bristles with downward-pointing barbs (retrorse) and typically 1(2) at base of spikelet .. Setaria adhaerens [pics]
1' Blades 2−4(−8) mm wide; panicle (including bristles) 5−7 mm diameter, the bristles with upward-pointing barbs (antrorse) and 4−12 at base of spikelet
2 Annuals, lacking knotlike nodes; panicle 15−35 mm long, lacking pulvinus at base of lateral branches; bristles in 2 unequal clusters .. Setaria pumila
2' Perennial herbs, with knotlike nodes; panicle 25−70 mm long, with pulvinus at base of lateral branches; bristles not in 2 unequal clusters .. Setaria parviflora
1 Annuals, with 1 principal, erect shoot; inflorescence dense and mostly fusiform, 90−250 × 15−30 mm, with stiff lateral branches; achenes ± spheroid, 3.9−4.3 × 4.1−4.5 × 2.7−3.1 mm, orangey to golden brown with black glumes .. Sorghum bicolor subsp. bicolor [pics]
1' Perennial herbs, rhizomatous and having several−many ascending to spreading principal shoots; inflorescence ovoid and open, 150−450 mm long, with flexible lateral branches; achenes ± obovoid, ± 3 × 1.9−2.3 mm, dull reddish brown with blackish glumes and having persistent whitish stalks of adjacent spikelets .. Sorghum halepense [pics]
1 Shoots having 3−5 cauline leaves with blades typically 350−700+ mm long, having the blade twisted 180° near base so upper actually functions as lower surface; margins of upper sheath conspicuously ciliate flanking ciliate ligule; lemma with dense, straight hairs 1−3.5 mm long; panicle mostly 300−600 mm long .. Stipa coronata [pics]
1' Cauline leaves, if present, with blades to 350 mm and never twisted 180°; margins of upper sheath ciliate or not at top; lemma, if pubescent, with hairs < 1 mm long
2 Sheath of cauline leaves conspicuously < internode and often flaring from stem; blades remaining ± flat and mostly 4−12 mm wide; lemma not forming a crown at tip with erect hairs, its awn somewhat curved and wavy, 2.9−4 mm long and never twisted or sharply bent .. Stipa miliacea var. miliacea [pics]
2' Sheath of cauline leaves not as above; blades when removed or water-stressed becoming strongly inrolled upward (involute) and appearing cylindric and < 3 mm wide; lemma forming crown at tip with erect hairs, its awn 20+ mm long, aging twisted and with at least 1 sharp bend
3 Lemma hiding fruit 6−7 mm long + crown; awns 70−95 mm long
4 Crown of lemma 0.2−0.5 mm long with bristles 0.8−0.9 mm long; awn basal diameter 0.2−0.3 mm diameter, at maturity with 1 sharp bend and a weaker second bend .. Stipa cernua [pics]
4' Crown of lemma 0.6−1.1 mm long with bristles 0.25−1.1 mm long; awn basal diameter 0.4−0.55 mm diameter, at maturity with 2 sharp bends .. Stipa pulchra [pics]
3' Lemma hiding fruit 5−6 mm long + crown 0.25−0.3 mm long, bristles on crown < 0.5 mm long; awns 20−46(−55) mm long, with 1 bend, ± 0.15 mm diameter at base .. Stipa lepida [pics]
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013