Bromus hordeaceus
Bromus
brome mou, lesser soft brome, lopgrass, soft brome, soft chess
brome, chess
2-70 cm, erect or ascending.
5-190 cm.
closed to near the top, usually pubescent;
auricles sometimes present;
ligules membranous, to 6 mm, usually erose or lacerate;
blades usually flat, rarely involute.
1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets;
branches shorter than the spikelets, ascending to erect, straight or almost so.
panicles, sometimes racemes in depauperate specimens, erect to nodding, open to dense, occasionally 1-sided;
branches usually ascending to spreading, sometimes reflexed or drooping.
(11)14-20(23) mm, lanceolate, terete to moderately laterally compressed;
florets 5-10, bases concealed at maturity;
rachilla internodes concealed at maturity.
5-70 mm, terete to laterally compressed, with 3-30 florets;
disarticulation above the glumes, beneath the florets.
pilose or glabrous;
lower glumes 5-7 mm, 3-5-veined;
upper glumes 6.5-8 mm, 5-7-veined;
lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm;
awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity;
anthers 0.6-1.5 mm.
unequal, usually shorter than the adjacent lemmas, always shorter than the spikelets, glabrous or pubescent, usually acute, rarely mucronate;
lower glumes 1-7(9)-veined;
upper glumes 3-9(11)-veined;
lemmas 5-13-veined, rounded to keeled, glabrous or pubescent, apices entire, emarginate, or toothed, usually terminally or subterminally awned, sometimes with 3 distinct awns or unawned;
paleas usually shorter than the lemmas, ciliate on the keels, adnate to the caryopses;
anthers (2)3.
equaling or shorter than the paleas, thin, weakly inrolled to flat.
sheaths densely, often retrorsely, pilose;
upper sheaths pubescent or glabrous;
ligules 1-1.5 mm, hairy, obtuse, erose;
blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy.
= 7.
= 28.
Bromus hordeaceus
Bromus
Bromus hordeaceus is native to southern Europe and northern Africa. It is weedy, growing in disturbed areas such as roadsides, fields, sandy beaches, and waste places, and can be found in many locations in the Flora region, with the exception of the central Canadian provinces and most of the southeastern United States. Its origin is obscure. Ainouche et al. (1999) reviewed various suggestions, and concluded that at least one of its diploid ancestors may have been an extinct or undiscovered species related to B. caroli-henrici, a diploid species.
The four subspecies are usually morphologically distinct. Ainouche et al. (1999), however, found no evidence of genetic differentiation among them.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Bromus grows in temperate and cool regions. It is estimated to include 100-400 species, the number depending on how the species are circumscribed. Of the 52 species in the Flora region, 28 are native and 24 are introduced. The native perennial species provide considerable forage for grazing animals, with some species being cultivated for this purpose. The introduced species, all but three of which are annuals, range from sporadic introductions to well-established members of the region's flora. Many are weedy and occupy disturbed sites. Some are used for hay; others have sharp, pointed florets and long, rough awns that can injure grazing animals.
This treatment is based on one submitted by Pavlick, who died before it could be reviewed and edited. It has been substantially revised by Anderton to meet the requirements for publication in this volume. The majority of Pavlick's taxonomic concepts are retained, despite the necessity for overlap in many key leads; time constraints prevented a thorough investigation of problematic taxa. The treatment recognizes taxa at both the subspecies and varietal rank; this simply reflects the decisions of the original author. We thank Hildemar Scholz of the Botanic Garden and Botanical Museum Berlin-Dahlem, Free University Berlin, for providing accurately identified specimens of the weedy European species for use in preparing the illustrations, and for his helpful suggestions for the keys and descriptions.
In the keys and descriptions, the distances from the bases of the subterminal lemma awns to the lemma apices are measured on the most distal florets in a spikelet.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lemmas (7)8-11 mm long, usually pubescent or pilose. | → 2 |
2. Awns more than 0.1 mm wide at the base, straight, erect; culms (3)10-70 cm long | subsp. hordeaceus |
2. Awns less than 0.1 mm wide at the base, often divaricate or recurved at maturity; culms 15-25(60) cm long | subsp. molliformis |
1. Lemmas 6.5-8(9) mm long, glabrous or pubescent. | → 3 |
3. Culms (3)10-70 cm long; panicles up to 10 cm long, usually with more than 1 spikelet; lemmas usually glabrous; caryopses usually as long as the paleas; habitat various | subsp. pseudothomineii |
3. Culms 2-16 cm long; panicles 1-3 cm long, often reduced to 1 spikelet; lemmas pubescent or glabrous; caryopses shorter than the paleas; plants of maritime or lacustrine sands | subsp. thotninei |
1. Lemmas strongly keeled, at least distally; spikelets strongly laterally compressed; lower glumes 3-7(9)-veined | sect. Ceratochloa |
1. Lemmas rounded over the midvein; spikelets terete to moderately laterally compressed; lower glumes 1-5-veined. | → 2 |
2. Awns, if present, arising less than 1.5 mm below the lemma apices; lemma apices entire, emarginate, or with teeth less than 1 mm long. | → 3 |
3. Lower glumes 1-3-veined; upper glumes 3-5-veined; plants perennial or annual, if annual, the lower glumes 1-veined and the upper glumes 3-veined | sect. Bromopsis |
3. Lower glumes 3-5-veined; upper glumes 5-9-veined; plants annual or biennial, if biennial, the upper glumes 7-veined and/or the lateral veins of the lemmas prominently ribbed | sect. Bromus |
2. Awns arising 1.5 mm or more below the lemma apices, lemma apices entire, emarginate, or with teeth to 5 mm long. | → 4 |
4. Awns usually geniculate, sometimes only divaricate, lemma teeth 2-3 mm long, usually aristate, sometimes only acuminate | sect. Neobromus |
4. Awns straight, arcuate, or divaricate, not geniculate, sometimes absent; lemma teeth absent or to 5 mm long, acuminate. | → 5 |
5. Lower glumes 1-3-veined; upper glumes 3-5-veined; spikelets with parallel or diverging sides in outline, often widening distally; lemma apices bifid, teeth (0.8)1-5 mm long | sect. Genea |
5. Lower glumes 3-5-veined; upper glumes 5-9-veined; spikelets with parallel or converging sides in outline; lemma apices entire to bifid, teeth less than 1 mm long, apices sometimes split and teeth appearing longer | sect. Bromus |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
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- Wikipedia
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- Local floras: CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora,
MN Wildflowers, MO Plants, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
